By Richard M. Sullivan, DDS
Only 20 years ago, the term "osseointegration" was virtually unknown within the United States. The use of endosseous implants to replace dentition, although not unheard of in 1980, fell outside the American dental mainstream in general practice. This article reviews some of the key developments that have ensued since then. Special attention is paid to the concept of osseointegration as it applies to dental general practitioners.
Tooth loss is a traumatic, even devastating, occurrence; and this has doubtless been true throughout human history. It is not surprising, then, that humans for millennia have sought to replace their lost dentition.1 The Etruscans are believed to have created bridgework fashioned from oxen bones some 2,500 years ago. Likewise, the notion of dental implants has its roots in antiquity. Archeologists have found evidence that occupants of what is now Honduras as long as 1,000 years ago developed a way to use tooth-shaped stones as dental implants.
In Europe, the earliest reference to an implant in modern literature appeared in a French work published in 1809; and by the late 1800s, dentists on both sides of the Atlantic were experimenting with implants made of such things as extracted teeth (human and animal) and lead. As the first half of the 20th century unfolded, dental innovators continued to search for materials and designs that would survive for more than a brief period after implantation. One breakthrough came in 1941, when a Swedish doctor named Gustav Dahl placed a metal structure below the periosteum; vertical extensions protruded through the gingiva. Impressed by this work, two dentists from Providence, R.I., Aaron Gershkoff and Norman Goldberg, brought the technique for placing subperiosteal implants to the United States, an achievement that attracted attention from other American dental practitioners. In 1951, 30 dentists met in St. Louis to form the American Academy of Implant Dentures (later known as the American Academy of Implant Dentistry).2
Another advance came with the work of Leonard I. Linkow of New York, who in 1964 introduced a self-tapping titanium implant. For cases in which bone was limited, Linkow later created a blade implant that eventually became the most widely used implant design in the 1970s.3
By 1978, a National Institutes of Health-Harvard University consensus conference was held to examine the implant modalities predominant at that time: subperiosteal, blade, vitreous carbon, and staple. This conference identified benefits and risks of implants, and a panel made specific recommendations for patient informed consent. As a historical note, Dr. Isaih Lew, then associate clinical professor of implant dentistry at New York University, had wanted screw-shaped implants to be included in the conference. Because they were not "current technology" in the United States at the time and the conference organizers were unaware of European developments, the program excluded them.4
v European Efforts
By the time the first Harvard consensus conference was held, a number of crucial developments were already under way in Europe. In Switzerland, Dr. Andre Schroeder, chairman of the University of Berne, was working to develop a dental implant system for clinical use. This work was done in conjunction with the Institute Straumann, a pioneer in the use of metal products in orthopedic surgery. Dr. Schroeder's experiments, first reported in 1976 in the German-language Swiss Dental Journal, histologically demonstrated the in-growth of bone into titanium plasma-sprayed hollow endosseous implants.5
At the same time, Professor Willi Schulte of the University of Tübingen in Germany was reporting success with immediate placement of vitreous carbon implants after dental extraction.6 Work with this design would eventually lead to the Frialit-2 implant.
v Brånemark's Contribution
In Sweden, similar research was to have an even more profound impact on dentistry. It
had its genesis in an accidental discovery made in the 1950s by a Swedish physician named
Per-Ingvar Brånemark. An anatomical and experimental biologist, Brånemark was
interested in studying bone healing response and regeneration. To observe the functioning
of bone marrow in vivo, a process known as vital microscopy, he adapted an experimental
chamber that had been used in England for insertion into rabbit ears. Unable to obtain
tantalum (the material used in the original design), he instead used titanium to make a
chamber that could be inserted into rabbit legs to allow
microscopic visualization of vital processes. After a months-long series of investigations, he sought to retrieve the chamber for reuse and found to his annoyance that it could not be removed from the rabbit bone.6
Brånemark reportedly was not struck by the significance of this turn of events until
some time after 1960, when he accepted a professorship in the Department of Anatomy at
Gothenburg University. There, using an adaptation of the titanium chamber placed in the
upper arms of human "volunteers" (also known as graduate students), he and his
team investigated the workings and structure of human blood cells under a number of
conditions, including response to cigarette smoking. This work yielded a great deal of
information about the nature of blood, and it showed the researchers that the titanium
serving as lens casings appeared uniquely compatible with the human soft tissue and skin,
provoking no adverse immunological reactions. At this point, Brånemark began to
contemplate using titanium for medical applications (Figures 1 through 4).
 |
| Figures 1 through 4. Brånemark first used a lens encased in titanium to be installed in the bones of living rabbits. This method of observation is called vital microscopy. This was followed by titanium-sheathed lenses placed in graduate students' upper arms. These experiments in vital microscopy established both the bone and soft tissue compatibility of titanium as an accidental finding. |
In the years that followed, Brånemark and his team pursued this vision along a number of fronts. They designed titanium screws and inserted them into the jaws of beagle dogs, studying the conditions needed to achieve a solid bond between the bone and the metal (Figures 5 through 7). They studied the biomolecular processes that occur when titanium is placed in living tissue. As this understanding advanced, Brånemark believed it necessary to coin a new term to refer to the in-growth of the bone into the threads and crevices of titanium. He finally settled upon "osseointegration," derived from the Latin words os (bone) and integro (to renew).
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| Figures 5 through 7. Functioning implants supporting fixed bridges in dogs and the eventual analysis of the implants provided understanding of the mechanisms to achieve this state of osseointegration before the first humans were operated on. |
By 1965, the Swedish team felt ready to apply its findings to human patients. Although they had originally planned to work with knee and hip joint surgeries, they instead selected as their first human subject a 34-year-old man who had been born with a deformed chin and jaw. Brånemark inserted four titanium fixtures into the man's mandible, and several months later he used the fixtures as the foundation for a fixed set of false teeth. The fixtures survived, the patient's life was transformed, and Brånemark resolved to develop more techniques for dealing with dental rehabilitation.
By 1975, Brånemark's findings and techniques had won approval from an independent
team of three professors who reported to the Swedish National Health and Welfare
Board that "treatment with a jawbone-anchored bridge construction can and should be
used as a complement to conventional prosthetics." A year later, in April of 1976,
the Brånemark method became fully covered by the Swedish national health insurance
system, and Brånemark began training the first Swedish dental experts in his techniques
in October 1977.
Almost five more years would pass, however, before Brånemark's findings would explode like a bombshell upon the consciousness of North American dentists. George Zarb, a dentistry professor from Toronto University who had trained under Brånemark in Sweden and then replicated his results independently, orchestrated this development. In May of 1982, Zarb organized the Toronto Conference on Osseointegration in Clinical Dentistry. The well-respected Zarb personally invited all the leading researchers in American and Canadian dentistry to the conference, and representatives from more than 70 universities responded. At this forum, Brånemark presented the results of his 15 years of meticulous human and animal research.
The weight of the scientific evidence, combined with Brånemark's charismatic personality, convinced a substantial percentage of the Toronto attendees that dental implants should at last be taken seriously. Shortly after the conference, researchers from the Mayo Clinic and Mayo Medical School obtained training in Brånemark's methods in Sweden; and the following year, the Mayo Clinic became one of five academic institutions in North America designated to train dental specialists (oral surgeons and, later, periodontists) in the surgical techniques. Under Brånemark's initial policy, restoration was to be carried out by prosthodontic specialists (with general dentists to follow).
Another consequence of the 1982 Toronto conference was the formation of a study club by a group of dental clinicians from the greater New York area. Their intent was to share research and information about osseointegration, and they eventually formed a national organization to foster education and advancement in the field of implant dentistry. In April of 1986, the first annual meeting of the Academy of Osseointegration was held in Chicago. It was at this point that a differentiation between implant-delivery formats became apparent in the United States. In a general sense, "multimodal implant dentistry" encompasses a wide range of formats, including blade or plate-form implants, subperiosteal, ramus frame, and cylindrical endosseous implants. These implants may rest on or be encapsulated within the bone. Today, when people use the term "osseointegration" they generally imply the installation of cylindrical implants in a manner to ensure rigid fixation of the implant without an intervening fibrous or soft-tissue layer. The osseointegration approach as the foundation for tooth replacement by far predominates other methods, but other implant modalities continue to have adherents.
In the early 1980s, recognizing the need for research to substantiate patient safety for dental implants based on research, an American Dental Association council adopted a resolution that permitted dental implants to be submitted for review. In 1985, Nobelpharma, the company manufacturing Brånemark’s implants for commercial use, submitted the first application, with approval coming the following year.
Since 1985, the American Dental Association's initial use of the word "approval" has given way to the term "acceptance." Eleven implant systems have received the ADA Seal of Acceptance (Table 1). In addition, two implant systems have received provisional acceptance: Astra Tech Implants for partially edentulous indications (Astra Tech, Inc.) and MicroVent Dental Implants (Sulzer Dental, Inc.).
Figure 8. "Osseointegration" implies rigid adaptation of
the implant in the host bone site, with no intervening soft tissue layer visible at the
light microscope level.
During the past 20 years, the field of osseointegration has witnessed a number of significant developments in the United States. One of the most notable is the expansion of the treatment indications. Treatment indications are a method of segmenting the field of osseointegration for discussion purposes; historically, dental restorations supported by osseointegrated implants evolved in this order:
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The fully edentulous lower jaw (Figures 9 through 15); |
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The fully edentulous upper jaw; |
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The short-span edentulous segment; and |
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The missing single tooth. |
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| Figure 10. | Figure 11. |
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| Figure 12. | Figure 13. |
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| Figure 14. | Figure 15. |
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| Figure 10. | Figure 11. |
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| Figure 12. | Figure 13. |
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| Figure 14. | Figure 15. |
| Figures10 through 15. Osseointegrated dental implants were first applied to the fully edentulous jaws. The rigid functional stability they provided was superior to previous augmentation methods. In Sweden, there was an emphasis on fixed restorations in both jaws. Other parts of the world, including the United States, have developed overdenture alternatives utilizing dental implants. | |
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| Figures 16 and 17. Soon after rehabilitation of the fully edentulous patient was introduced, American dentists started applying these principles to the missing single tooth and short-span segmental restoration. |
Treatment indications are important in any discussion of osseointegrated dental implants because not all concepts apply to all indications. The subjective symptoms of the patient seeking treatment, the patient's expectations regarding treatment outcome, anatomical limitations, and the components used all may vary widely, depending upon the treatment indication.
When Brånemark presented his findings at the 1982 Toronto conference, dental implants up to that point had only been utilized for fully edentulous jaws (upper or lower), and the treatment was only recommended for individuals in this category. That might appear to defy logic, since placement of implants for a fully edentulous arch may appear more complex than replacing only one tooth or using implants to support a short-span bridge.
However, the context of Brånemark's early research explains why the field developed as it did. Anxious to avoid the possibility of making any patient's condition worse, Brånemark selected for his early research subjects only individuals whom he classified as "dental cripples." These were people suffering from catastrophic dental failures, for whom traditional treatments were no longer an option. For such people, any success with dental implants would be an improvement.
Soon after the first Americans were trained in Brånemark's method in Sweden, they began to adapt and apply these methods for other treatment indications, specifically single-tooth and short-span fixed partial dentures. In one sense, this was a logical thing to do. If Brånemark demonstrated that a full arch of teeth could be successfully restored on four or five implants, it seemed an obvious extrapolation that a three-unit bridge could be done on two implants (Figures 16 and 17).
| Table 1. Implant Systems With Acceptance | |
| Manufacturer | Implant System |
| Astra Tech, Inc | Astra Tech Implant |
| Nobel Biocare USA Inc. | Brånemark System Dental Implants |
| IMZ 4.0mm Implant System | |
| Steri-Oss HA-Coated Titanium | |
| Screw Type Dental Implants | |
| Steri-Oss Titanium Screw Type Dental Implants |
|
| Straumann Co. | |
| ITI Dental Implants | |
| Sulzer Dental, Inc. | Integral Endosseous Implant System |
| Integral Omniloc Endosseous Implant System | |
| Omniloc Dental Implant System With Interface Ring | |
| Spline HA-Coated Cylinder Dental Implant System | |
However, while the early adopters experienced many successes with the expanded utilization, unanticipated complications and failures also resulted. The first studies demonstrating the efficacy of implants for single-tooth and short edentulous span indications began appearing in the early 1990s. As they have accumulated, understanding has grown of the unique biomechanical factors that must be considered for each treatment indication. Dentists and their patients can benefit from the experiences gained during these developmental years.
A second important development has been the gradual shift in attention to the creation of esthetic restorations. In the mid-1980s, implant practitioners were focusing on functional rehabilitation of the fully edentulous patient. Esthetic results were secondary to the profound impact on patients' life quality that resulted from having a truly fixed restoration after functioning with denture adhesives for 30 years or more. But as dentists sought to offer osseointegrated dental implants on a more routine and elective basis, demand for esthetic results that were at least comparable to other forms of dentistry grew.
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| Figure 24 | |
| Figures 18 through 24. The transition from functional full arch to esthetic single tooth replacement has entailed a deeper understanding of the implications of soft tissue on the esthetic result. Advances in components, such as this ceramic abutment, allow cemented restorations analogous to everyday restorative procedures in general practice. In this instance, the osseointegration approach prevents the preparation of an unrestored canine tooth, and also prevents the remaking of a crown that would require a midline shade match. | |
Implant dentistry in the1990s experienced a transition from functional rehabilitation to esthetics, with esthetic results improving throughout the decade. One aspect of this transition has been the development of components specifically designed for the single-tooth restoration or segmental bridge (Figures 18 through 24).
What has also emerged is a more detailed understanding of the relationship between residual bone volume and papilla height, along with treatment planning to correct soft-tissue deficits either surgically or prosthetically. It has become apparent that changes in the soft-tissue contours in the post-tooth-loss resorptive process have the greatest impact upon the final restorative esthetic result. During the past two decades, the focus on bone and implants has been joined with an equal focus on ceramics and soft tissue (Figure 25).3
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| Figure 25. The physiologic health of the living bone, periimplant tissue, and functioning restoration help determine long-term success. |
Another significant change has come in the manner in which osseointegrated dental implant restorations are delivered. In the 1980s, dental implant restorations were not only primarily of a full-arch nature, but they were also screw-retained. That is, the dental restoration was attached to the implant or implant abutments with the use of small set screws. From a research perspective, especially with unknown outcomes at the outset, this was very practical. It made the restoration retrievable by the dentist so it could be modified or the status of the individual implants could be experimentally assessed. During the 1990s, however, as more general dentists and dental laboratory technicians have entered the field, a rapid changeover to cemented restorations has occurred. These implant restorations more closely resemble their natural tooth counterparts and do not require the same intricacies in fabrication as a screw-retained restoration. Long-term provisional cements seek to retain the retrievability of cemented restorations. Today, virtually any restoration can be done in either a screw-retained or cemented fashion, provided this preference is accounted for in the treatment-planning process.
Today, approximately 450,000 osseointegrated implants are being placed every year. The fastest-growing treatment indication is the single-tooth replacement. At one time, a dental implant was thought to be an aggressive treatment of last resort. Today, replacing a missing single tooth with an implant-supported crown has a reasonable expectation of a 95 percent success rate. Compared to the preparation of healthy, vital natural abutment teeth, many dentists realize and embrace the idea that the single-tooth implant is actually a more conservative treatment for the patient in the long term (Figures 26 through 36).
Despite all the successes, a couple of factors have impeded still wider acceptance of implants as a treatment modality. For one thing, dental insurance continues to lag behind the technology. Academic training in implant techniques has also developed slowly. For the most part, implant dentistry still is not being taught at the undergraduate level. Dentists must acquire their knowledge about treatment planning, implant placement, and hands-on restorative procedures as a postgraduate pursuit, either from residencies or approved continuing education courses. Ongoing study-club participation supports development in a group-learning context and provides the opportunity for mentorship.
Even with the obstacle of dental implant proficiency being a post-graduate pursuit, implant-supported dental restorations are definitely on an upswing in the United States. More patients are choosing to have their teeth replaced without having their adjacent teeth ground. They are understanding the long-term benefits and decreased risk of complications by avoiding preparation of abutment teeth.
Dentists are recognizing that implant-supported restorations are often the most conservative and predictable approach to tooth replacement. Offering patients this alternative represents the standard of care in informed consent. The author's position is that every restorative dentist in the United States should at least be providing cemented single-tooth and short-span segmental restorations on dental implants, and lower overdentures on ball attachments.
The historical perspective of osseointegration demonstrates that these developments are now part of the mainstream armamentarium for routine treatment planning for the replacement of missing teeth. Dental patients can experience routine benefits with minimum risks and complications based on the careful developmental footsteps established by the foresight of the early innovators.
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| Figure 26. Figure 27. |
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Figure 28. Figure 29. |
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Figure 30. Figure 31. |
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| Figure 32. Figure 33. |
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| Figures 26 through 36. Dental implants have evolved to the point of becoming the more conservative treatment to replace a missing single tooth. Placement of two implants in a one-stage surgical procedure provide the foundation for customized titanium abutments and all-ceramic crowns to be cemented without preparation of unrestored and vital potential abutment teeth. |
Author
Richard M. Sullivan, DDS, is the clinical director of Nobel Biocare USA, Inc.
References
Legends
Figures 1 through 4. Brånemark first used a lens encased in titanium to be installed in the bones of living rabbits. This method of observation is called vital microscopy. This was followed by titanium-sheathed lenses placed in graduate students' upper arms. These experiments in vital microscopy established both the bone and soft tissue compatibility of titanium as an accidental finding.
Figures 5 through 7. Functioning implants supporting fixed bridges in dogs and the eventual analysis of the implants provided understanding of the mechanisms to achieve this state of osseointegration before the first humans were operated on.
Figure 8. "Osseointegration" implies rigid adaptation of the implant in the host bone site, with no intervening soft tissue layer visible at the light microscope level.
Figures 9 through 15. Osseointegrated dental implants were first applied to the fully edentulous jaws. The rigid functional stability they provided was superior to previous augmentation methods. In Sweden, there was an emphasis on fixed restorations in both jaws. Other parts of the world, including the United States, have developed overdenture alternatives utilizing dental implants.
Figures 16 and 17. Soon after rehabilitation of the fully edentulous patient was introduced, American dentists started applying these principles to the missing single tooth and short-span segmental restoration.
Figures 18 through 24. The transition from function full arch to esthetic single tooth replacement has entailed a deeper understanding of the implications of soft tissue on the esthetic result. Advances in components, such as this ceramic abutment, allow cemented restorations analogous to everyday restorative procedures in general practice. In this instance, the osseointegration approach prevents the preparation of an unrestored canine tooth, and also prevents the remaking of a crown that would require a midline shade match.
Figure 25. The physiologic health of the living bone, peri-implant tissue, and functioning restoration help determine long term success.
Figures 26 through 36. Dental implants have evolved to the point of becoming the more conservative treatment to replace a missing single tooth. Placement of two implants in a one-stage surgical procedure provide the foundation for customized titanium abutments and all-ceramic crowns to be cemented without preparation of unrestored and vital potential abutment teeth.
Copyright 2001 Journal of the California Dental Association. Vol. 29, No. 11, Nov. 2001
Reprinted with permission.
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In an effort to resolve some of the existing controversies and to deal with the gaps in knowledge in dental implantology, the NIDR in conjunction with the National Institutes of Health (NIH) Office of Medical Applications of Research and the Food and Drug Administration convened a consensus development conference on June 13-15, 1988. It also is evident that the tremendous interest in this field as well as many clinical case series studies also are responsible for the NIH convening this second Consensus Development Conference on Dental Implants within a 10-year period. A group of distinguished speakers presented current data on many aspects of implantology. The audience of approximately 750 included an illustrious group of clinicians, researchers, and educators, many of whom were responsible for the development and advancement of the field of dental implantology. Following 1-1/2 days of presentations by experts in the relevant fields and presentations by professional organizations involved in dental implantology, a consensus panel consisting of representatives from the fields of dental implantology, oral surgery, anatomy, bone biology, periodontology, materials and engineering, epidemiology, statistics, behavioral science, and the public considered the evidence and formulated a consensus statement responding to the following questions:
The use of dental implants to provide support for replacement of missing teeth is becoming an important component of modern dentistry. As a result of advances in research on implant design, materials, and techniques the use of these devices has increased dramatically in the past few years and is expected to expand further in the future. Many types of implants are now available for application to different clinical cases, and an increasing number of dentists have become involved in this form of treatment. It has been estimated that the overall number of dental implants inserted in the United States increased fourfold from 1983 to 1987, and during that same period the number of practitioners who perform implant therapy increased tenfold. It is estimated that as many as 300,000 dental implants will be used in the United States by 1992. Growth in dental implant utilization also is evident in Europe and Japan.
The magnitude of the missing tooth problem (edentulism) in the United States adult population remains considerable. Although there has been a tremendous reduction in coronal dental caries during the past several decades, this improvement is evident mainly in the younger segments of the population, with individuals over 35 years of age still showing a significant prevalence of full or partial edentulism. According to the 1985-1986 National Institute of Dental Research's (NIDR) national survey of oral health conducted on U.S. employed adults and seniors attending multipurpose senior centers, approximately 42 percent of Americans over 65 years of age and 4 percent of those 35 to 64 years of age are totally edentulous. Moreover, those over 65 years with teeth have lost an average of more than 10 of 28 teeth, and employed dentate persons ages 55 to 64 have lost an average of 9 of 28 teeth. Thus, there are many individuals in this country who could conceivably benefit from dental implant therapy.
Many individuals with edentulism can be treated with partial or complete traditional removable dentures or fixed bridges. However, these prostheses are not satisfactory for a significant number of individuals who have lost the tooth-bearing portions of the bone and simply cannot manage removable prostheses, or are medically compromised and cannot properly masticate food. Moreover, there is a strong suggestion that a substantial number of patients prefer implant-supported prostheses over soft tissue supported prostheses.
Research advances in dental implantology have led to the development of several different types of implants, and it is anticipated that continued research will lead to improved devices. At present, continued evaluation is necessary to determine that appropriate implant devices are available to meet the therapeutic demands of the different portions of the jawbones and the unique needs of patients.
Criteria of success vary with different implant systems. Therefore, it is difficult to compare certain types of implants for which success criteria and indications may be different. Furthermore, for implants that are comparable, proper research designs for comparison (randomized, controlled trials) have not been used. Thus, the panel could only conclude that there is evidence from a number of case series studies that when specific types of dental implants are inserted by clinicians experienced with the respective techniques, a large proportion of implants remains in place for periods of 10 years or more.
However, it is difficult to make definitive statements on the long-term effectiveness of dental implants from these case series studies because of unreported information and the lack of uniform application of proper research designs. Although the ideal research design for documenting the effectiveness of new treatment techniques should be a randomized, controlled clinical trial, case series studies are capable of providing limited evidence when proper methods are used. Future case series studies should conform to the following principles:
The case series studies available generally did not follow these principles. In addition, little data were available on traditional treatment outcome measures such as patient satisfaction, esthetics, comfort, lack of physical and psychological symptoms, phonetics, and masticatory efficiency.
The evidence that dental implants are effective in providing total support for restorations is based on several case series studies with a duration of 10 years or more and several others that lasted for more than 5 years. The evidence that implants are effective in the long term in partially tooth-supported restorations is based on fewer studies that have been conducted for periods of up to 10 years. Because of the lack of randomized trials to compare different implant systems and the lack of uniformity in defining success, it is not possible to make judgments on the comparative merits of different implant systems. Additional knowledge about the biology of hard and soft tissues coupled with technological advances in the construction and insertion of various implants will likely result in a trend toward improved long-term success rates. This expectation is evident in the historical learning curve apparent when survival rates of specific implant systems are monitored. For example, in the case of endosseous implants, available long-term data are derived from studies in which many factors now known to affect implant survival were not properly appreciated when the longitudinal studies were begun. Included among these factors were bone preparation procedures that failed to stay within certain thermal limits now known to be critical for bone cell survival. Furthermore, the insertion of implants in a one-stage procedure may not have ensured absence of functional forces during the critical early stages of wound healing. These techniques may explain in part the early failure of some implants and the frequent fibrous adaptation of bone to some implants. Although it is not clear that the fibrous tissue interface compromises the long-term success rate of endosseous blade implants, the best reported long-term survival rates for root-form implants have been achieved with systems that have bone at the interface.
No reliable data are available on the effect of variations in restorative techniques on the long-term success rate of implants nor are data available on the long-term use of implants in edentulous children.
Dental implants may be classified by type as endosseous, subperiosteal, transosteal, intramucosal, endodontic, and bone substitutes. The data that were presented at this conference were confined to the first three types. These are the only ones for which indications and contraindications have been promulgated in this statement. These implant types are subdivided as follows:
Endosseous:
| Root form.
| Blade (plate) form.
| Ramus frame. | |
n Subperiosteal:
| • Complete.
| • Unilateral.
| • Circumferential. | |
n Transosteal:
| • Staple.
| • Single pin.
| • Multiple pin
| |
For long-term successful performance of all dental implant types the following general factors should be considered:
| Biomaterials.| • Biomechanics. | • Dental evaluation. | • Medical evaluation. | • Surgical requirements. | • Healing processes. | • Prosthodontics. | • Postinsertion maintenance.
| |
All practitioners involved in patient care should be knowledgeable regarding these
factors and their interrelationships. Standards of dental practice would suggest the
following general contraindications for the above three categories of dental implants:
| • Debilitating or uncontrolled disease. |
| • Pregnancy. |
| • Lack of adequate training of practitioner. |
| • Conditions, diseases, or treatment that severely compromise healing,
e.g., including radiation therapy. |
| • Poor patient motivation. |
| • Psychiatric disorders that interfere with patient understanding and
compliance with necessary procedures. |
| • Unrealistic patient expectations. |
| • Unattainable prosthodontic reconstruction.| • Inability of patient to manage oral hygiene. | • Patient hypersensitivity to specific components of the implant.
| |
With regard to indications for a specific implant type, the bone available to support the implant is the primary factor after prosthodontic diagnosis and treatment plan. This bone is measured in width, height, length, anatomical contour, and density. These physiological and anatomical factors may be altered by either osteoplasty or augmentation of the bone. In addition, other factors affecting indications for implant type are the degree and location of the edentulism of the patient. Indications for each implant type are specified below:
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ENDOSSEOUS, root form: |
| Adequate bone to support the implant with width and height being the primary
dimensions of concern.
| • Maxillary and mandibular arch locations.
| • Completely or partially edentulous patients.
| |
n ENDOSSEOUS, blade (plate) form:
n ENDOSSEOUS, ramus frame:
n SUBPERIOSTEAL, complete, unilateral, circumferential:
n TRANSOSTEAL, staple, single pin, multiple pin:
Implant treatment is delivered in several ways: (1) by multidisciplinary teams of dentists in which an oral surgeon or periodontist performs the surgical component of the implant and a prosthodontist performs the prosthetic component; (2) by individual implan-tologists with extensive training in both the surgical and prosthetic components who perform all aspects of the procedure; and (3) by general dentists who may perform both components or the prosthetic component only and whose training in implant techniques may vary widely.
Unfortunately, there are no data available to the panel that address the surgical, restorative, and periodontal requirements for the individuals managing the implant patient.
Minimal training has not been precisely defined, but the panel recommends that the individual that assumes the surgical treatment phase be well prepared in accepted surgical methodologies. In as much as the restorative procedures employed in implantology differ from those in traditional restorative dentistry procedures, the panel recommends instruction in the restorative phase of implantology. These programs also should include expertise in short- and long-term tissue maintenance addressing gingival status as well as radiographic evaluation of tissue support.
Patient selection should be restricted to those patients who show a need and motivation for the implant procedures. The evaluation of the recipient should include a survey of adequate bone structure, medical history, and, where indicated, medical laboratory studies and consultation with the patient's physician. The use of computerized tomography for evaluation of maxillary and mandibular anatomy is suggested when more accurate information regarding implant placement is needed. The patient's dental evaluation also should include a psychosocial appraisal of his or her suitability for implant procedures when psychological symptoms are present.
The panel supports a multidisciplinary approach, and we recommend a preimplant consultation involving the professional participants with the patient. Postimplant procedures should include communication, monitoring, and collection of recorded data by the professional. We recommend that the patient be thoroughly instructed in maintenance therapy with the understanding that the patient serves as a cotherapist.
There is a lack of data detailing the minimum requirements for an adequate maintenance program. The proper recall interval, methods of plaque and calculus removal, and use of antimicrobial agents are critical variables that need further evaluation.
There are at least three areas in which the assessment of patient risk should be considered, including risks associated with the surgery and/or anesthesia, psychological risks, and medical risks. Risks associated with the surgical procedure may include inadvertent perforation of the nasal sinus, local and systemic infection, and nerve injury. Before surgery a medical history should be taken to evaluate the history of the presenting problem and chief complaints. A review of the current status of the patient's organ systems should be made.
Children need special consideration, given long-term morbidity concerns, requirements
of growth, manual dexterity, and coping skills.
Psychological stressors and motivational factors have been shown to influence patient response to surgery and long-term compliance with oral hygiene maintenance. These stressors include both familial and social environmental factors such as job satisfaction, financial status, and health concerns. Specific mental conditions may require psychological intervention to assist with patient cooperation and outcome satisfaction. Individuals with excessive neurotic concerns, depression, anxiety, and specific medical fears or previous negative medical or dental experiences should be appropriately evaluated. Relative contraindications include individuals with psychotic symptomatology, especially requiring psychotropic medication, and somatization disorders or chronic pain complaints where medical symptoms are exhibited in the absence of organic evidence. Tobacco use, alcohol, or drug dependency may interfere with good nutrition or compliance requirements.
Temporary conditions that may result from implant placement may include pain and swelling, speech problems, and gingivitis. Long-term problems may include nerve injury, local bone loss exacerbation, hyperplasias, local or systemic bacterial infection, and infectious endocarditis in susceptible individuals, including those with body part replacement. Existing natural dentition may be compromised.
Factors related to prediction of health risks need to be continuously assessed before the surgical decision, after implantation, during the temporary waiting period, following the loading period, and at 6-month intervals throughout the followup period. Reliable and valid standardized measurements sensitive to both psychological and physical factors should be used in clinical prospective studies to enhance comparison across studies.
v What Are the Future Directions for Research On Materials and Designs of Dental Implants and On Clinical Management?
Materials and Designs
Dental implants have many compositions and surface textures. Manufacturing processing techniques affect these surfaces in subtle ways. To better control clinical protocols, characterization of these surfaces is essential. Ion release from the implant may influence biocompatibility (bioacceptance). To achieve a more complete understanding of tissue response to the implant, basic experiments in host-implant physiology and biology must be continued. Dynamic studies in laboratory animals also should be completed. Other matters that warrant further study are the influence of surface preparation on wettability or bonding of tissues to the implant and the effect of galvanic couples resulting in corrosion. Studies must document the possible release of constituents of
implant materials at the trace and subtrace level into other tissues to determine their significance with respect to toxicity, mutagenicity, or carcinogenicity.
Basic research should be emphasized to develop materials and methodology to allow for predictable bone augmentation. The implant- host interface should be studied to characterize wound repair and tissue adaptation in the peri-implant region.
Among the factors involved in the design of an implant are the force components produced during loading, the dynamic nature of loading, and the mechanical and structural properties of the prosthesis of stress transfer to tissues. Unfortunately, accurate data on such parameters are incomplete. Such information is essential for efficient design of implants.
Clinical Management
Randomized, controlled, prospective multicenter clinical studies should be initiated. These studies should investigate the role of several factors on the long-term effectiveness of dental implants. These factors include, in addition to implant characteristics, the operator's skills in implant placement, tissue management, various patient characteristics, including the intraoral location of the implant, and occlusal and prosthetic considerations.
The panel feels that one important method of accumulating accurate data on implant performance is to establish a National Dental Implant Registry, which will standardize reporting forms to collect information on this activity in the United States. A rating scale based upon function and discomfort should be developed for evaluation of all implant procedures. In this way, the causative factors involved in success and failure of implants can be more accurately identified. Consideration also should be given to the establishment of centers for training, treatment, and research in dental implantology.
To ensure continued safety evaluation of dental implants, long-term prospective studies should specifically address failures due to medical or psychological complications that led to premature removal of the implant. When failures occur in either implants or an existing dentition, a failure analysis should be performed and reported.
All patient data should be recorded, including age, education, socioeconomic level, number of previous implants, nutritional status, periodontal status, acute or chronic coexisting diseases, and pharmacologic use.
Patient Considerations
Considering that edentulousness is frequently the result of the patient's high susceptibil
ity to destructive forms of periodontal disease, the relationship of implant success rates to the patient's relative susceptibility to periodontitis should be studied. Also, data are needed on both the acute and chronic or long-term morbidity that may result from various types of implants.
The public is entitled to educational materials that enable informed participation in implant treatment decisions, and the panel recommends that these materials be developed.
Conclusion
During the 10 years since the first Consensus Development Conference on Dental Implants, a great deal of activity in the field has occurred with the development of better materials and newer techniques that have resulted in improved implant-bone interface. This conference examined case series studies, and the panel concluded that a large proportion of endosseous, subperiosteal, and transosteal implants have remained in place for more than 10 years. The indications and contraindications of various types of dental implants have been described. The complexity of the surgical, restorative, and periodontal procedures used to successfully insert and maintain dental implants demonstrates the need for a multidisciplinary approach in this field.
Long-term studies that concurrently compare various types of implants are needed to provide information beyond mere survival rates. Functional success of various implants should include such criteria as the ability to support fixed or removable prostheses in the absence of discomfort, the presence of satisfactory esthetics, and clinical and radiographic evidence of tissue health. A suggestion for the establishment of a National Dental Implant Registry was proposed with the objective of collecting data and documentation on various procedures being conducted in the United States. Future studies in materials and techniques were proposed.
Consensus Development Panel
D. Walter Cohen, D.D.S.
Conference and Panel Chairperson
President
The Medical College of Pennsylvania
Philadelphia, Pennsylvania
James D. Beck, Ph.D.
Professor and Chairman
Department of Dental Ecology
University of North Carolina at Chapel Hill
School of Dentistry
Chapel Hill, North Carolina
Chester W. Douglass, D.M.D., Ph.D.
Associate Professor and Chairman
Department of Dental Care Administration
Harvard School of Dental Medicine
Boston, Massachusetts
Manville G. Duncanson, Jr., D.D.S., Ph.D.
Professor and Chairman
Department of Dental Materials
University of Oklahoma College of Dentistry
Oklahoma City, Oklahoma
Lawrence J. Emrich, Ph.D.
Cancer Research Scientist
Department of Biomathematics
Roswell Park Memorial Institute
Buffalo, New York
Max A. Listgarten, D.D.S.
Professor and Chairman
Department of Periodontics
University of Pennsylvania School of
Dental Medicine
Philadelphia, Pennsylvania
Barbara G. Melamed, Ph.D.
Professor of Psychology
Departments of Clinical and Health
Psychology and Community Dentistry and
Psychiatry University of Florida College of Health
Related Professions Health Sciences Center
Gainesville, Florida
Carl E. Misch, D.D.S.
Codirector
Oral Implantology Center
University of Pittsburgh School of Dental Medicine
Director Misch Implant Institute
Dearborn, Michigan
Ralph W. Phillips, D.Sc., M.S.
Research Professor of Dental Materials
Indiana University School of Dentistry
Indianapolis, Indiana
Mary Kaye Richter
Executive Director
National Foundation for Ectodermal Dysplasias
Mascoutah, Illinois
Elaine A. Stuebner, D.D.S., F.A.C.D.
Professor, Oral and Maxillo Facial Surgery
Department of Pediatric Dentistry
College of Dentistry
University of Illinois
Chicago, Illinois
Allan M. Weinstein, Ph.D.
President and Chief Executive Officer IatroMed, Inc.
Phoenix, Arizona
Speakers
Robert E. Baier, Ph.D., P.E.
Director Health-care Instruments and Devices Institute
State University of New York at Buffalo
Buffalo, New York
Burton E. Balkin, D.M.D.
Director Implant Dentistry
University of Pennsylvania
School of Dental Medicine
Narberth, Pennsylvania
Charles L. Bolender, D.D.S., M.S.
Professor and Chairman
Department of Prosthodontics, SM-52
University of Washington
School of Dentistry
Seattle, Washington
Per I. Branemark, M.D.
Professor
Institute for Applied Biotechnology
SWEDEN
John B. Brunski, Ph.D.
Associate Professor
Department of Biomedical Engineering
Rensselaer Polytechnic Institute
Jonsson Engineering Center
Troy, New York
Ulrich M. Gross, M.D.
Professor
Institute of Pathology,
Steglitz Clinic
Free University of Berlin
FEDERAL REPUBLIC OF GERMANY
Jack E. Lemons, Ph.D.
Professor and Chairman
Department of Biomaterials
University of Alabama at Birmingham
School of Dentistry
Birmingham, Alabama
Krishan K. Kapur, D.M.D., M.S.
Professor-in-Residence Removable Prosthodontics
University of California at Los Angeles
Chief Dental Services
Veterans Administration Medical Center
Sepulveda, California
Victor J. Matukas, D.D.S., Ph.D., M.D.
McCallum Professor and Chairman
Department of Oral and Maxillofacial Surgery
University of Alabama at Birmingham
Birmingham, Alabama
Ralph V. McKinney, Jr., D.D.S., Ph.D.
Professor and Chairman
Department of Oral Pathology
Medical College of Georgia
School of Dentistry
Augusta, Georgia
Roland M. Meffert, D.D.S., F.A.C.D., F.I.C.D.
Professor and Chairman
Department of Periodontics
Louisiana State University
School of Dentistry
New Orleans, Louisiana
Anthony H. Melcher, M.D.S., H.D.D., Ph.D., D.Sc.
Professor of Dentistry
Faculty of Dentistry
Associate Dean of Life Sciences
School of Graduate Studies
University of Toronto
Toronto, Ontario CANADA
Lawrence H. Meskin, D.D.S., Ph.D.
Dean of Graduate School
University of Colorado
Health Sciences Center
Denver, Colorado
Joseph R. Natiella, D.D.S.
Professor and Chairman
Department of Stomatology and
Interdisciplinary Sciences
State University of New York at Buffalo
School of Dental Medicine
Buffalo, New York
Michael G. Newman, D.D.S.
Adjunct Professor
University of California at Los Angeles
School of Dentistry
Section of Periodontics
Center for Health Sciences
Los Angeles, California
W. Eugene Roberts, D.D.S., Ph.D.
Professor of Orthodontics
Director
Bone Research Laboratory
University of the Pacific
School of Dentistry
San Francisco, California
Paul A. Schnitman, D.D.S., M.S.
Associate Professor and Head
Department of Implant Dentistry
Harvard School of Dental Medicine
Boston, Massachusetts
Leonard B. Shulman, D.M.D., M.S.
Associate Clinical Professor and Head
Department of Implant Research
Forsyth Dental Center
Boston, Massachusetts
Dennis C. Smith, D.Sc., Ph.D., M.Sc., F.R.S.C.
Professor and Head
Department of Biomaterials
Faculty of Dentistry
University of Toronto
Toronto, Ontario CANADA
Charles M. Weiss, D.D.S., F.I.C.D.
President
Director of Research and Development
Oratronics, Inc.
The Chrysler Building
New York, New York
Philip Worthington, M.D., F.D.S.R.C.S.
Professor of Oral and Maxillofacial Surgery
Department of Oral and Maxillofacial Surgery
University of Washington
Seattle, Washington
Franklin A. Young, Jr., D.Sc., M.S.E.
Professor and Chairman
Department of Materials Science
Medical University of South Carolina
Charleston, South Carolina
George A. Zarb, B.Ch.D., D.D.S., M.S., M.S., F.R.C.D.(c)
Professor and Chairman
Department of Prosthodontics
University of Toronto
Toronto, Ontario CANADA
Planning Committee
D. Walter Cohen, D.D.S.
Conference and Panel Chairperson President
The Medical College of Pennsylvania
Philadelphia, Pennsylvania
Michael J. Bernstein
Director of Communications
Office of Medical Applications of Research
National Institutes of Health
Bethesda, Maryland
Jerry M. Elliott
Program Analyst
Office of Medical Applications of Research
National Institutes of Health
Bethesda, Maryland
Albert D. Guckes, D.D.S., M.S.D.
Chief Commissioned Officer's Dental Clinic
Warren Grant Magnuson Clinical Center
National Institutes of Health
Bethesda, Maryland
H. David Hall, D.M.D., M.D.
Professor and Chairman
Department of Oral Surgery
Vanderbilt University School of Medicine
The Vanderbilt Clinic
Nashville, Tennessee
Jack E. Lemons, Ph.D.
Professor and Chairman
Department of Biomaterials
University of Alabama at Birmingham School of Dentistry
Birmingham, Alabama
Jack L. Lewis, Ph.D.
Professor of Orthopaedic Surgery and Mechanical Engineering
University of Minnesota Medical School
Minneapolis, Minnesota
Marie U. Nylen, D.D.S., Dr. Odont. h.c.
Director Extramural Program
National Institute of Dental Research
National Institutes of Health
Bethesda, Maryland
Anthony Rizzo, D.M.D.
Planning Committee Chairperson
Chief Periodontal and Soft Tissue Diseases Branch
National Institute of Dental Research
National Institutes of Health
Bethesda, Maryland
Patricia Sheridan
Technical Writer/Editor
Office of Planning, Evaluation, and Communication
National Institute of Dental Research
National Institutes of Health
Bethesda, Maryland
D. Gregory Singleton, D.D.S.
Dental Officer Center for Devices and
Radiological Health
Food and Drug Administration
Silver Spring, Maryland
Thomas M. Valega, Ph.D.
Special Assistant for Manpower Development and Training
Extramural Program
National Institute of Dental Research
National Institutes of Health
Bethesda, Maryland
Philip A. Watson, D.D.S., M.S.D.
Professor
Department of Biomaterials
Faculty of Dentistry
University of Toronto
Toronto, Ontario CANADA
Wayne T. Wozniak, Ph.D.
Assistant Secretary
Council on Dental Materials, Instruments, and Equipment
American Dental Association
Chicago, Illinois
Conference Sponsors
National Institute of Dental Research
Harald Loë Director
The Office of Medical Applications of Research
John H. Ferguson Director
The Food and Drug Administration
Frank Young Commissioner
Wise Choices for Maxillary
Single-Tooth Implants
By Belinda L. Gregory-Head, BDS, MS; Alex McDonald PhD, DDS; and Eugene LaBarre DMD, MS
Abstract: The purpose of this article is to demonstrate to general practitioners who have no experience with dental implant treatment the esthetic limitations of such treatment. The criteria for wise case selection will be described so that esthetic excellence can be predictably achieved in general practice. A checklist of criteria will be provided as a treatment-planning tool to determine if a patient is likely to have an esthetically successful outcome.
While the anterior implant patient may come into the office fixed on the notion of having an implant, further questioning often reveals that his or her chief concern is to have a missing tooth replaced with something that looks good, feels good, and works like a real tooth. The challenge of treatment planning is to fulfill these goals. If any of these criteria cannot be satisfied, then the treatment may be considered a failure.1-3
California dentists may very well face a greater challenge than most in satisfying the esthetic demands of their patients. Practitioners here must satisfy an extremely esthetically aware population. Unreasonable demands from patients and unrealistic promises by practitioners can led to unsatisfactory experiences for all parties. A clear understanding of the esthetic limitations of dental implants and the practitioner's own expertise in this area will reduce the risk of unforeseen problems.
Long-term data on the success of implant-supported single-tooth restorations in the anterior maxilla have been available since 19964 and have been corroborated in many more recent studies.5-7 Success rates of between 90 percent and 98 percent have been consistently reported. Early papers documented complications as being mainly mechanical in nature, including screw loosening, component fracture, and loss of integration. Studies seeking to define success in the anterior region have, until recently, focused on retention and not on esthetic success.
The push for better function and esthetics has led to a growing appreciation of the biomechanical limitations of implants. Wider-diameter implants have been introduced.8,9 This addition to the armamentarium along with better engineering of the components and screw-tightening systems10,11 have brought us to a time when a dental implant can be a predictable and functional success. Advances in determining the ideal position of the implant and more accurate surgical techniques have greatly enhanced esthetic outcomes.12 These have been significant improvements, but they may never be enough to allow a dental implant to be the treatment of choice for all edentulous spaces in the anterior region.
The purpose of this article is to demonstrate that there are some esthetic limitations to dental implant treatment. It is aimed at practitioners with no experience with implant treatment. The criteria for wise case selection will be described so that esthetic excellence can be predictably achieved in general practice.
The following checklist of nine issues will be discussed. The checklist provides a treatment-planning tool to determine if a patient is likely to have an esthetically successful outcome:
Patients' desires are often overlooked in guides to treatment planning, yet they may be the most important criterion assessed by the dentist. An experienced practitioner will be better able to judge a patient's esthetic demands, but in any case a clear understanding of the patient's wishes must be established before any treatment recommendations are made. It is possible to satisfy some demanding patients, but significant cooperation is required of them. It is critical that the patient be involved and educated as to the risks, esthetic or otherwise, that may be inherent in the treatment. The patient will be expected to maintain rigorous dental hygiene and deal with various provisional restorations as treatment progresses. For this reason, an emphasis on the team approach is recommended. The patient should become an integral member of the treatment team along with the laboratory technician, hygienist, and dentists.13,14 Pretreatment intraoral photographs and carefully selected patient-education videos can help bring the patient's level of understanding up to that required for an esthetic case.15 For a practitioner's first anterior implant case, it is recommended that he or she choose a cooperative patient with realistic expectations.
After initial assessment of patient expectations, the evaluation of the smile line or gingival display will provide the best indicator as to the esthetic risk of the case. Excessive gingival display may be due to a number of factors, including vertical maxillary excess, short clinical crowns, and hypermobility of the upper lip.16 Whatever the underlying etiology, it is important to evaluate the patient's ability to display gingiva.17,18 Being asked to smile can result in a forced or half smile and may be misleading. It is recommended that the patient be asked to sneer or lift his or her upper lip as high as possible so the dentist can assess the situation. If a "gummy" smile is presented, the patient should be fully informed of the difficulties ahead. Additional periodontal procedures such as crown lengthening of remaining maxillary dentition may be considered.19 If the patient is unable to display gingival tissue, it is still important to discuss the risks, but it is also possible to reassure the patient that any gingival esthetic compromise will be hidden from view. The single most important factor for esthetic success in anterior implants is the smile line. It is highly recommended that the first few patients treated in a practice have a low lip line.
The morphology of gingival tissue has been discussed extensively in the periodontal literature. It is relevant to esthetic success with anterior implants since gingival recession has been identified as a significant complication in these cases.20 The forms of
periodontium can be broadly divided into two distinct "biotypes," which have been correlated to specific tooth forms.21 Thin, highly scalloped gingival tissues are associated with long, narrow, and tapered tooth forms. The second important biotype is the thick, flat, more fibrous form associated with a shorter, wider, and squarer tooth shape. The two tissue types are associated with different responses to inflammatory stimuli. The thin, highly scalloped type tends to respond with marginal recession and loss of papillary height, while the thick, fibrous type tends to develop a chronic inflammatory response that may result in periodontal pocketing.22 An ideal first implant patient would have an abundance of thick, flat, fibrous gingival tissue and therefore be more resistant to gingival recession around the restoration. This biotype also allows for the use of metal abutments with less chance of show-through at the gingival margin. This gingival form is also associated with a favorable square tooth form.
The existence of papillae filling the interdental spaces is a key indicator for future success. If the remaining dentition exhibits "black triangles" due to lack of complete fill of the spaces, then the risk of similar incomplete fill around the implant restoration is high. "Black triangles" may be pre-existing for a number of reasons, including gingival recession, highly tapered triangular tooth form, and previous periodontal surgery. The problem is difficult to resolve, and the patient should be educated as to the esthetic risks involved. Attempts have been made to classify loss of papillae and provide prognostic indicators.23 Surgical techniques aimed at regenerating lost papillae have been developed.24,25 Such regeneration remains challenging, and it may be unwise for a general dentist who is new to implants to treatment plan a first case anticipating the need for additional periodontal plastic procedures.
The position of the osseous crest is a critical indicator for potential loss of papillae after a surgical intervention such as extraction or implant placement.26 The greater the distance from the free gingival margin to the osseous crest, the greater the esthetic risk. A sounding depth of greater than 3 mm at the midfacial aspect or 4 mm at the interproximal position would indicate an esthetic risk.27 An ideal patient would therefore have excellent periodontal health and a high, flat bone profile.
Complete papillary fill of the interdental space after implant restoration is also closely related to tooth form, particularly the position and shape of the contact areas.
It has been determined that if the apical limit of the contact area is 5 mm or less from the osseous crest, then a papilla will be present almost 100 percent of the time in the
Figure 2. The triangular crown form is associated with thin, highly scalloped gingival tissues.
Figure 4. The broader, squarer tooth form is associated with thicker, flatter gingival
tissue.
Figure 1. The tapered crown form results in a short, incisally positioned contact area. A
small interdental space is visible in this natural dentition.
Figure 3. Shorter, broader tooth forms have longer contact areas and better prognosis
for fill of the interdental space.
Figure 6. Example of a patient with excellent bone height and favorable tooth form, note
long contact areas.
Figure 5. Ideal vertical placement of implant 3 mm apical to the cement oenamel junction of adjacent teeth allows for appropriate emergence of crown form (Nobel Biocare implant with a custom abutment).
natural dentition. An additional 1 mm distance drops the likelihood of a papilla being present to only 56 percent.28 While the position of the osseous crest may be difficult to adjust, the position of the contact areas may be changed by the restorative dentist. A careful evaluation of the patient's natural tooth morphology should be made. Long, narrow tapered teeth tend to have short incisally positioned contact areas (Figure 1) likely to be further from the osseous crest and therefore likely to have incomplete fill of the interdental space. The triangular shape (Figure 2) is also associated with thinner highly scalloped gingival tissue that tends to recede. More predictable anterior esthetics will be gained with patients who have broader tooth forms and longer, more cervically positioned contact areas (Figures 3 and 4). Pretreatment photographs are an essential tool for evaluation of tooth shape and educating the patient as to potential risks.
Crown shape is related to root form. Ironically, unfavorable clinical crowns with a triangular morphology taper into a narrow neck and narrow, tapered root form with more interdental bone. This would be a favorable variable providing for more bone between the titanium implant and the adjacent natural roots. This makes placement easier and reduces the risk of root proximity issues. It is generally believed that at least 1.5 mm of healthy bone should exist between the dental implant and the adjacent root surface. Recent work on treatment-planning criteria for multiple implant restorations has suggested that at least 3 mm should separate neighboring implants to reduce interimplant crestal bone loss and hence preserve vital osseous support for the interimplant papillae.29
Adjacent tooth morphology has an additional effect on treatment planning a single dental implant. The length of the adjacent clinical crowns will have biomechanical consequences for the implant restoration regardless of tooth shape. Neighboring long clinical crowns must be replicated in the final restoration and may result in a long lever arm acting on the dental implant itself. Unless excellent bone height is available to facilitate the placement of a long implant, an unfavorable crown-to-implant ratio will result for most implant systems available.
In relation to adjacent tooth morphology, the ideal implant patient would have short, wide clinical crowns with long contact areas and existing papillae.
Occlusal forces act obliquely on anterior teeth. Likewise, an anterior implant restoration will be loaded nonaxially. Longer implants resist nonaxial loading better and have been associated with higher success rates. Implants of 11 mm or longer have proven to be successful in the anterior maxilla.30 If the replacement being proposed is for a single tooth only, there is often adequate remaining bone height to facilitate fixture placement.
However, the osseous crest may be positioned apical to ideal. Ideal placement of a dental implant will result in the top of the fixture being placed 2-4 mm apical to the cemento-enamel junction of the adjacent teeth (Figure 5). The exact ideal distance will be modified by the diameter of the chosen implant, the desired emergence profile of the final crown, and the tissue biotype. If the top of the implant closely replicates the diameter of the missing tooth, the placement will be more coronal. If the top of the implant is narrower, then placement will be deeper to facilitate harmonious broadening of the crown form as it emerges from the tissue. Implant placement in a patient with thin, highly scalloped tissue would also be deeper to accommodate the tendency to recede and to reduce the risk of metal show-through.
Available bone height can be evaluated with periapical radiographs and clinical examination. The ideal patient would have adequate height to house a long implant (13 mm or more) with the crest of the residual ridge 2 mm below the cementoenamel junction of the adjacent teeth (Figure 6).
Successful placement of dental implants depends on adequate osseous housing in all dimensions. At least 1.5 mm of healthy bone is required between the implant and neighboring root surfaces and the "standard" implant from most manufacturers approximates 4 mm in diameter. Therefore the minimum mesiodistal space that can accommodate an implant between two teeth is 7 mm. Replacement of a central incisor or cuspid would not usually present a problem in this dimension, but loss of a small lateral incisor could present risk. In such a case, a narrower implant may be considered or orthodontic correction carried out.
The implant must also be fully encased in bone in the labiolingual dimension. Again, a minimum of 7 mm is required for a standard diameter implant. It is this requirement that presents the most common complication of treatment planning for the anterior maxilla. The labial plate of cortical bone is often missing and remodeled before implant treatment planning begins. This may be due to previous periodontal or periapical infection, traumatic loss, or loss during extraction. Even if an atraumatic extraction technique is employed, the labial plate will inevitably remodel and become positioned lingually within three to six months. A distinct labial concavity will be evident when the site is viewed from the occlusal aspect (Figures 7 and 8).
A significant labial defect that would result in the facial aspect of the implant being located entirely outside the osseous structures should be considered for hard tissue augmentation prior to implant placement. A less-significant defect may be accommodated by slightly deeper and more lingual placement of the fixture to allow for good osseous contact while maintaining the proper emergence profile (Figure 9).
Figure 7. Occlusal view of poten-tial implant site showing significant labial concavity. Hard tissue onlay grafting will idealize the site prior to implant placement.
Figure 8. The same patient as Figure 6. Excellent ridge width in both edentulous
lateral incisor sites.
Figure 9. Graphic illustration of placement lingually and apically from ideal due to loss
of labial cortex. This technique can be used to avoid grafting but should be employed
with caution since significant deviation from ideal position can result in unfavorable
cantilevers and maintenance problems (Illustration by Annette Kramer).
Figure 10. CT scans can significantly increase accuracy in determining available bone for
fixture placement (Image made with GE Lightspeed Plus, Advanced Imaging Center,
Sacramento, Calif.).
Figure 12. Morphology of provisional is accurately duplicated in final restoration.
Figure 11. Ideal placement and provisionalization of implant #5 site results in excellent
emergence profile.
Figure 13. Final restoration in place.
Figure 14. Key anatomic features of an ideal anterior implant patient: low smile line; abundance of attached keratinized tissue (thick, flat biotype); papillae preserved after extraction; wide, square-shaped teeth with long contact areas; and excellent bone height and width (Illustration by Annette Kramer).
Assessment of available bone in the mesiodistal and buccolingual dimensions can be achieved with a thorough clinical examination, or measuring directly from study casts. Anesthesia and "sounding" of the osseous structures is also a useful technique. The most accurate diagnostic aid is the CT scan (Figure 10). Unlike Panorex films, where measurements have to be corrected for varying magnification, the CT film can be measured directly and is accurate to within 0.1 mm. Dental CT scans have become economic (as low as $275 to $350 per arch). They should be considered if there is a question as to whether bone augmentation will be required.
After thorough treatment planning and ideal fixture placement, there is still opportunity for esthetic excellence or mediocrity in the restoration phase. Several months of provisionalization allows for maturation of the gingival tissues to an appropriate (noncylindrical) emergence profile. The tooth form generated through excellent provisionalization must be carried through to the final restoration so that crown and papilla form is maintained (Figures 11 through 13).
Restoring dental implants in the esthetic zone can be fun if wise choices are made. If the factors discussed above are carefully considered, patients who present significant esthetic risks will be screened out and patients with predictably good prognoses will be taken on. While much emphasis has been placed on the anatomic features of the ideal first patient (Figure 14) possibly more important is the patient's desire to cooperate with the team and have realistic expectations. A thorough understanding of the esthetic limitations of dental implants by all members of the team will result in a rewarding and satisfying experience.
Authors
Belinda L. Gregory-Head, BDS, MS, is an associate professor and director of dental implants at the University of the Pacific School of Dentistry.
Alex McDonald, PhD, DDS, is an associate professor and surgical coordinator at the Implant Clinic at UOP School of Dentistry.
Eugene LaBarre, DMD, MS, is an associate professor and chair of removable prosthodontics at UOP.
Legends
Figure 1. The tapered crown form results in a short, incisally positioned contact area. A small interdental space is visible in this natural dentition.
Figure 2. The triangular crown form is associated with thin, highly scalloped gingival tissues.
Figure 3. Shorter, broader tooth forms have longer contact areas and better prognosis for fill of the interdental space
Figure 4. The broader, squarer tooth form is associated with thicker, flatter gingival tissue.
Figure 5. Ideal vertical placement of implant 3 mm apical to the cementoenamel junction of adjacent teeth allows for appropriate emergence of crown form (Nobel Biocare implant with a custom abutment).
Figure 6. Example of a patient with excellent bone height and favorable tooth form, note long contact areas.
Figure 7. Occlusal view of potential implant site showing significant labial concavity. Hard tissue onlay grafting will idealize the site prior to implant placement.
Figure 8. The same patient as Figure 6. Excellent ridge width in both edentulous lateral incisor sites.
Figure 9. Graphic illustration of placement lingually and apically from ideal due to loss of labial cortex. This technique can be used to avoid grafting but should be employed with caution since significant deviation from ideal position can result in unfavorable cantilevers and maintenance problems (Illustration by Annette Kramer).
Figure 10. CT scans can significantly increase accuracy in determining available bone for fixture placement (Image made with GE Lightspeed Plus, Advanced Imaging Center, Sacramento, Calif.).
Figure 11. Ideal placement and provisionalization of implant #5 site results in excellent emergence profile.
Figure 12. Morphology of provisional is accurately duplicated in final restoration.
Figure 13. Final restoration in place.
Figure 14. Key anatomic features of an ideal anterior implant patient: low smile line; abundance of attached keratinized tissue (thick, flat biotype); papillae preserved after extraction; wide, square-shaped teeth with long contact areas; and excellent bone height and width (Illustration by Annette Kramer).
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6. Naert I, Koutsikakis G, et al, Biologic outcome of single-tooth implant restorations as tooth replacements: a long-term follow-up study. Clin Implant Dent Relat Res 2(4):209-18, 2000.
7. Scholander S, A retrospective evaluation of 259 single-tooth replacements by the use of Brånemark implants. Int J Prosthodont 12(6):483-91, 1999.
8. Boggan RS, Strong JT, et al, Influence of hex geometry and prosthetic table width on static and fatigue strength of dental implants. J Prosthet Dent 82(4):436-40, 1999.
9. Ivanoff CJ, Sennerby L, et al, Influence of implant diameters on the integration of screw implants. An experimental study in rabbits. Int J Oral and Maxillofac Surg 26(2):141-8, 1997.
10. Lang LA, May KB, Wang RF, The effect of the use of a counter-torque device on the abutment-implant interface. J Prosthet Dent 81(4):411-7, 1999.
11. Schulte JK, Coffey J, Comparison of screw retention of nine abutment systems: a pilot study. Implant Dent 6(1):28-31, 1997.
12. Davarpanah M, Martinez H, Tecucianu JF, Apical-coronal implant position: recent surgical proposals. Technical note. Int J Oral Maxillofac Implants 15(6):865-72, 2000.
13. Narcisi EM, Culp L, Diagnosis and treatment planning for ceramic restorations. Dent Clin North Am 45(1):127-42, 2001.
14. Hess D, Buser D, et al, Esthetic single-tooth replacement with implants: a team approach. Quintessence Int 29(2):77-86, 1998.
15. Dunn JR, Hutson B, Levato CM, Photographic imaging for esthetic restorative dentistry. Compend Contin Educ Dent 20(8):766-8, 1999.
16. Robbins JW, Differential diagnosis and treatment of excess gingival display. Pract Periodontics Aesthet Dent 11(2):265-72, 1999.
17. Morley J, Eubank J, Macroesthetic elements of smile design. J Am Dent Assoc 132(1):39-45, 2001.
18. Paul SJ, Smile analysis and face-bow transfer: enhancing aesthetic restorative treatment. Pract Proced Aesthet Dent 13(3):217-22, 2001.
19. Levine RA, McGuire M, the diagnosis and treatment of the gummy smile. Compend Contin Educ Dent 18(8):757-62, 1997.
20. Goodacre CJ, Kan JY, Rungcharassaeng K, Clinical complications of osseointegrated implants. J Prosthet Dent 81(5):537-52, 1999.
21. Siebert J, Lindhe J, Esthetics and periodontal therapy. In Lindhe J, ed, Textbook of Clinical Periodontology, 2nd ed. Munksgaard, Copenhagen, 1989, Chap 19.
22. Olsson M, Lindhe J, Periodontal characteristics in individuals with varying forms of upper central incisors. J Clin Periodontol 18:78-82, 1991.
23. Nordland WP, Tarnow DP, A classification system for loss of papillary height. J Periodontol 69:1124-26, 1998.
24. Blatz MB, Hurzeler MB, Strub JR, Reconstruction of the lost interproximal papilla-presentation of surgical and nonsurgical approaches. Int J Periodontics Restorative Dent 19(4):395-406, 1999.
25. Salama H, Salama M, et al, Developing optimal peri-implant papillae within the esthetic zone: guided soft tissue augmentation. J Esthet Dent 7(3):125-9, 1995.
26. Kois JC, Predictable single tooth peri-implant esthetics: Five diagnostic keys. Comp Contin Educ Dent 22(3):199-206, 2001.
27. Kois JC, Altering gingival levels: the restorative connection part 1: biologic variables. J Esthet Dent 6:3-9, 1994.
28. Tarnow DP, Magner AW, Fletcher P, The effect of the distance from the contact point to the crest of bone on the presence or absence of the interproximal dental papilla. J Periodontol 63:995-6, 1992.
29. Tarnow DP, Cho SC, Wallace SS, The effect of inter-implant distance on the height of inter-implant bone crest. J Periodontol 71:546-9, 2000.
30. Goodacre CJ, Kan JY, Rungcharassaeng K, Clinical complications of osseointegrated implants. J Prosthet Dent 81(5):537-52, 1999.
Copyright 2001 Journal of the California Dental Association. Vol. 29, No. 11, Nov. 2001
Reprinted with permission.
Dental Implant
By Gordon L. Douglass, DDS, and Robert L. Merin, DDS, MS
Abstract: Numerous clinical studies have shown that dental implants can be placed immediately in extraction sockets with success when sites are carefully selected. Dental implants have been placed at the time of extraction with a variety of techniques. All the techniques report survival rates of 94 percent to 100 percent over a varied healing period of three months to approximately seven years. This article will review clinical criteria for determining patient selection for immediate implants and the advantages and disadvantages of immediate implant placement.
During the past 10 years, numerous clinical studies have shown that dental implants can be placed immediately in extraction sockets with success when sites are carefully selected. Dental implants have been placed at the time of extraction with a variety of techniques including without augmentation, with bone grafting, with bone grafting and a barrier membrane, and with and without primary closure. The techniques report survival rates of 94 percent to 100 percent over a varied healing period of three months to approximately seven years.1-7 Investigators have reported high success rates with all type of implants, including screw, cylinder, Hydroxylapatite-coated, tapered, and single-stage.
This article will review the important clinical criteria for determining patient selection for immediate implants and the advantages and disadvantages of immediate implant placement. It will also discuss the clinical steps for the placement of dental implants in extraction sockets. The single-tooth implant restoration has been the most common immediate implant application, but immediate implants have also been successfully utilized in full-arch restorations.8 Single-rooted teeth, predominately incisors and premolars, have been the most frequent sites for immediate implants; but a study by Schwartz-Arad and colleagues evaluated molar immediate implants and found a success rate similar to healed molar sites in carefully selected cases.9
The first step in determining whether immediate implant placement is a reasonable clinical choice is evaluation of the potential implant site. Several classification systems have been proposed by a variety of authors, including Salamma, Gelb, and Becker.10-12 All the systems provide criteria for evaluating the bony morphology for immediate implant placement. The ideal extraction site for immediate implant placement is one where there is little or no periodontal bone loss on the tooth that is to be extracted, such as a tooth with endodontic involvement, root fracture, root resorption, periapical pathology, root perforation, or unfavorable crown to root ratio (not due to periodontal bone loss). In all studies, the investigators chose bony three to four walls and sufficient bone to stabilize the implant. Most researchers report desiring at least 3 to 5 mm of bone beyond the apex and a bony length of 10 mm or greater for immediate implant placement (Figure 1). There is general consensus that bony defects with two and three walls missing or severe labial and circumferential defects are not suitable for immediate implant placement. Wilson showed that the horizontal or circumferential component of the peri-implant defect was a critical factor relating to the final amount of histologic bone-implant contact, and that horizontal defects of less than 1.5 mm do not need membranes to obtain histologic osseointegration13 (Figure 2).
Therefore, immediate implant placement should be limited to those defects that have three- and four-walled sockets, minimal periodontal bone resorption, sufficient bone to stabilize the implant, and minimal circumferential defects. Initial implant stability is the most critical factor in implant osseointegration; therefore, an ideal site is one with significant alveolar bone around the socket enabling the implant to fill the socket space (Figure 3). Ivanoff and colleagues have shown that early mobility of implants greatly reduces their integration and clinical success.14
Figure 1a. Preoperative radiograph of tooth #4.
Figure 1b. Immediately after ITI implant placement.
Figure 2. Close adaptation of an implant to the crestal socket wall, within 1.5 mm.
Figure 1c. Two and one-half years after placement. Note that tooth #3 has endodontic pathology (Implant prosthetics by James M. Herron, DDS, Woodland Hills, Calif.).
Figure 3a. Preoperative view of tooth #25.
Figure 3c. Six months after placement (Implant prosthetics by Gregory W. Holve, DDS, valley Village, Calif.).
Figure 3b. ITI narrow neck implant immediately after placement.
Figure 4. Microsurgical scalpel (top) and periotome (bottom) can be used to help extract teeth.
Tooth Extraction
The first step in immediate implant placement after case selection is an atraumatic extraction. Every attempt should be made to minimize trauma to the alveolus during the extraction. The use of a minisurgical blade to make the initial sulcular incision around the tooth will facilitate separating the soft tissues from the root and cutting the periodontal ligament. In many cases, the sulcular incision will be the only incision needed. The periodontal ligaments can be further separated from the tooth with a periotome, which will help prevent fracture of the alveolus (Figure 4). Once the tooth has been loosened with the periotome, if there is adequate tooth structure, the tooth can be carefully removed with extraction forceps. If there is not adequate tooth structure to grip with forceps or rongeurs, then the extraction may be attempted with the periotome alone or by sectioning the root so that the remaining root fragments can be extracted without placing pressure on the alveolus. The socket is then debrided with curettes or rotary instruments. The resulting extraction socket is evaluated for osseous defects. If all four walls are intact and the circumferential defect is less than 1.5 mm, an implant well may be placed without the need for bone grafting or augmentation. If three or more walls are present or if the circumferential defect is greater than 1.5 mm, an implant may be placed; but bone grafting and protection of the socket with a membrane is recommended.
Implant Osteotomy
The next step is the preparation of the extraction area and the apical bone for the placement of the implant. The first step in the dental implant placement is the beginning of an osteotomy with a round bur or pilot drill. If the site is a maxillary anterior tooth, the osteotomy must be kept on the palatal aspect of the alveolus to prevent perforating the buccal plate. Once the osteotomy is complete to the desired depth with at least 3 to 5 mm of intimate implant to bone contact, an implant is placed. The implant must be stable within the osteotomy with no mobility. The implant may touch all of the bony walls of the extraction site but should not place undue pressure upon thin alveolar walls (Figure 5). Kohal and colleagues have shown that pressure of the implant on the bony walls of the alveolus can result in microfractures and early crestal bone loss.15 The ideal situation would be for the implant to be in contact with the socket without putting undue pressure on the socket walls unless the alveolus is very thick, leaving no gap between the occlusal part of the implant and surrounding socket walls (Figure 5). In other words, the postoperative radiographic appearance of an ideal immediate implant placement would look the same as a standard implant placement (Figure 6).
Figures 5a. Figures 5b.
Figures 5c.
Figure 5g. The implants at uncovering. Figure 5h. The final restorations.
Figures 5a through f. Implants are placed in extraction sites and extraction defects. Note that implants are placed at palatal aspect of the sockets with no pressure on the buccal place.
Figures 5e.
Figures 5f.
The space between the implant and socket wall has been an issue of concern and controversy. Studies have shown that close adaptation of the implant to socket wall promotes greater osseointegration13,16 (Figure 7). Additionally, in areas where there is a wide space from the implant to socket wall, better bone healing is achieved when an occlusive membrane is placed over the socket. In clinical studies, investigators have utilized a wide variety of techniques -- including the use of a bone graft to fill the gap and/or the use of an occlusive membrane to prevent epithelial perforation into the space between the implant and the socket wall_ to aid in the healing of this space.17-20 Bone healing in an implant osteotomy proceeds apical to coronal, therefore the coronal aspect becomes the most critical in the healing. An implant that appears to be clinically stable may have some fibrous tissue attachment at the coronal margin rather than true osseointegration, and this may not be detectable for a long time.
Current research favors the use of a barrier if a significant gap exists between the implant and the socket wall. Numerous occlusive barriers have been used, both resorbable and nonresorbable, to prevent epithelial migration into the socket area.21,22 In early studies, woven e-PTFE membrane exposure was a significant complication of membrane placement.23 Newer, more-stable resorbable membranes allow membrane exposure without complication. Certain barriers _ porcine collagen and freeze-dried dermas, and laminar freeze dried bone_ can be used in techniques that do not require primary closure24 (Figure 8).
Historically, most clinical studies have used primary closure of the flaps over implants placed in extraction sites. Becker and Becker used the inner portion of e-PTFE membrane as an occlusive barrier over immediate implants in four patients without primary closure.25 Rosenquist used a synthetic resorbable membrane as an occlusive barrier in 10 patients and a laminar freeze dried bone membrane as an occlusive barrier in 25 patients, without primary closure.10 The advantage of not having to obtain primary closure is the preservation of the gingival tissues (Figure 8f). The advantage of a resorbable membrane is that it does not have to be removed, and the collagen membranes and laminar freeze dried bone show excellent tissue compatibility. For single-stage implants, both resorbable and nonresorbable barriers have been used to cover the implant-to-socket-wall gap.26-29
Another choice is to use a single-stage implant that extends into the gingival space, or a healing cap or custom healing component on a two-stage implant, all of which will now fill the soft tissue portion of the socket completely or partially (Figures 9 and 10). The concern arises when a significant gap exists between the implant and the socket and the implant structure or healing cap is going to extend through the socket. Research favors the use of an occlusive barrier or membrane to protect the healing socket area.30
Figure 6b.
Figure 6c. Figure 6d.
Figure 6e. Figure 6f. Figure 6g.
Figures 6a through d. No. 11 is fractured, and #10 has irreversible mobility due to traumatic injury, which prohibits the replacement of the fixed bridge #11-15.
Figures 6i.
Figures 6h through k. The final implant restoration showing excellent preservation of the
gingival form and no difference on the radiographs between the implants in the immediate
and healed sites.
Figures 6j. Figures 6k.
Figure 7b. Immediately after placement of ITI 4.8 mm implant.
Figure 7c. Ten months postoperative radiograph (Implant prosthetics by David M. Campbell, DDS, Woodland Hills, Calif.).
A temporary prosthesis, either removable or fixed, can be placed over the implants. However, a removable prosthesis should not put pressure on the implant or it will result in premature loading of the implant. Premature loading or vibration of dental implants has been shown to delay osseointegration and retard bone healing.
Recently, there have been studies evaluating immediate loading of immediate placed
dental implants.31 This has primarily been done where there are four or more
implants extending around a curve that are rigidly splinted together.32 The
authors believe that it is premature to consider loading single implants at this time
since there are significant variables that may retard implant healing. The placement of a
temporary crown, even one that is out of function, transmits load to the implant. New
implant surfaces have been approved by the Food and Drug Administration for loading as
early as eight weeks so that the time from implant placement to the placement of a
temporary crown has shortened significantly, but the greater size of the bone-to-implant
gap around some immediate implants may require longer healing times. The early placement
of a temporary crown on an implant and the experimentation with immediate loading should
not be considered by those who do not have extensive experience in implant placement and
prosthetics.
Figure 8b.
Figures 8a and b. Preoperative photo and radiograph showing #9 with a vertical
fracture.
Figure 8c. A wide-diameter root form implant is placed, which reduces the distance between the socket walls and the implant.
One of the most critical factors in implant restorative esthetics is the gingival form. The gingival tissues can be shaped and managed by the temporary prosthesis and by the provisional crown that is placed on the implant prior to placement of the final crown (Figure 11). In areas where single-stage implants or a healing cap can be used, the implant itself may help to support the gingival tissues and the interdental papillae, which are critical for implant esthetics (Figure 10). In the restoration of dental implants in the esthetic zone of the maxillary anterior teeth, it is recommended that a temporary crown be considered as part of the restorative treatment plan to help shape and form the peri-implant tissues prior to placement of the final crown (Figure 8g).
If it is possible to place the dental implant with minimal disruption of the peri-implant
tissues and provide immediate support, the management of the tissues will be facilitated.
The use of anatomic gingival formers or single-stage implants and the placement of
implants without elevating a flap have significantly improved practitioners' ability to
readily achieve excellent peri-implant gingival form.
Figure 8e.
Figures 8d and e. Two resorbable collagen membranes are placed, one on the buccal because
of a narrow buccal late defect and one covering the implant, eliminating the need for
primary closure.
Figure 8g. Temporary restoration helping shape the gingival form.
Figure 8f. Healing at five weeks with preservation of gingival papillae.
Figure 8h. and i. The final restoration one year after completion.
Figure 8i.
Figure 9a. Preoperative view of tooth #21.
Figure 9b. ITI implant immediately after placement.
Figure 9c. Four months after placement. Note bone healing around neck of the implant.
Figure 10a and b. No. 7 fractured and nonrestorable.
Figure 10c and d. No. 7 fractured an immediate implant is placed.
Figures 10e and f. Final restoration exhibiting the same gingival form as the original
tooth.
Figure 11a. Preoperative #8 with a fractured root.
Figure 11b. Implant placement #8.
Figure 11d. Radiograph of implant #8.
Figure 11c. Surgical site sutured with minimal displacement of the interdental papillae.
Figures 11e and f. Temporary removable appliance used to shape and support the gingival papillae.
Figure 11h. Final crown with maintenance of interdental gingival form.
Figure 11g. Healing cap placed.
Figure 12a. Radiograph of #8 shows a large radiolucency associated with a root
fracture that precludes immediate implant placement.
Figure 12b through d. Extraction and augmentation of the socket.
Figure 12c. Figure 12d.
Figures 12e and f. Healing and tissue support from the removable appliance.
Figure 12f.
Figures 12h.
Figures 12g through i. Implant placement eight months later.
Figures 12i.
Figure 12j. Implant site and uncovering.
Figures 12k and l. Implant restored with temporary crown 12 months from extraction. The
two-stage approach takes considerably more time and more steps than immediate placement.
Figures 12l.
The primary advantages of immediate implant placement are the reduction in time of therapy, the reduction in surgical episodes, and preservation of the bone and gingival tissues. The greatest rate of bone resorption occurs during the first six months following tooth extraction unless an implant is placed or a socket augmentation procedure performed.30 The early maintenance of gingival form will greatly facilitate the peri-implant gingival tissue esthetics by maintaining support for the interdental papillae (Figure 11).
The primary disadvantage of immediate implant placement is the fact that the clinician
may not be able to place the implant at the time of extraction even though time has been
scheduled. The patient must always be informed that although an immediate placement will
be attempted, it is not guaranteed since there is always a possibility that factors such
as ankylosis, bone fractures of facial plates, socket expansion during extraction, or
extensive infection might make immediate placement impossible. These areas will require
extraction socket healing and possible augmentation before an implant can be placed
(Figures 12 and 13).
Figure 13a. Preoperative radiograph. Tooth #6 was not a good candidate for an immediate implant because the root fracture had caused too much vertical and horizontal bone loss on the facial bone.
Figure 13b. Preoperative photograph.
Figure 13c. Surgical view of missing facial bone.
Figure 13d. Photograph of extracted tooth.
Dental implants that are immediately placed into carefully selected extraction sockets have high survival rates comparable to implants placed in healed sites. The immediate-placement implants provide significant advantages of less surgical procedures, shorter treatment time, and the facilitation of improved esthetics. There are significant areas of information that need to be clarified regarding the use of bone grafts and membranes around immediately placed implants and the size of the space between the implant and socket wall. Until these are clarified with evidence-based clinical studies, clinical judgment behooves dentists to use prudence in their case selection for immediate implants. There must be adequate bone to give implant stability, and the bony walls around implants should be intact on at least three of the four sides. However, with these caveats, the immediate implant has now become a significant part of implant therapy and provides for timely esthetic implant restorations.
Authors
Gordon L. Douglass, DDS, maintains a private practice in Sacramento, Calif. Robert L. Merin, DDS, MS, is the immediate past president of the California Society of Periodontists. He is also a lecturer at the University of California at Los Angeles School of Dentistry and a consultant for the West Los Angeles Veterans Administration. He maintains a private practice in Woodland Hills, Calif. Dr. Merin is a diplomate of the American Board of Periodontology and a staff member of West Hills Hospital and Northridge Hospital.
References
1. Lazzara RJ, Immediate implant placement into extraction sites: Surgical and restorative advantages. Int J Periodont Restorative Dent 9:333-43, 1989.
2. Ashman A, An immediate tooth root replacement: An implant cylinder and synthetic bone combination. J Oral Implantol 16:28-38, 1990.
3. Parel SM, Triplett RG, Immediate fixture placement: A treatment planning alternative. Int J Oral Maxillofac Implants 5:337-45, 1990.
4. Barizilay I, Grasser GN, et al, Immediate implantation of a pure titanium implant into an extraction socket: Report of a pilot procedure. Int J Oral Maxillofac Implants 6:277-84, 1991.
5. Tolman DE, Keller EE, Endosseous implant placement immediately following dental extraction and alveoplasty: Preliminary report with 6 year follow-up. Int J Oral Maxillofac Implants 6:24-8, 1991.
6. Becker W, Becker BE, et al, Guided tissue regeneration for implants placed into extraction sockets: A study in dogs. J Periodontal 62:703-9, 1991.
7. Yukna RA, Clinical comparison of hydroxylapatite-coated titanium dental implants placed in fresh extraction sockets and healed extraction sites. J Periodontol 62:468-72, 1991.
8. Schwartz-Arad D, Chaushu G, Full-arch restoration of the jaw with fixed ceramometal prosthesis. Int J Oral Maxillofac Implants 13:819-25, 1998.
9. Schwartz-Arad D, Gorssman Y, Chaushu G, The clinical effectiveness of implants placed immediately into fresh extraction sites of molar teeth. J Periodontal 71:839-44, 2000.
10. Salama H, Salama M, The role of orthodontic extrusive remodeling in the enhancement of soft and hard tissue profiles prior to implant placement: A systematic approach to the management of extraction site defects. Int J Periodont Restorative Dent 13:313-33, 1993.
11. Gelb DA, Immediate implants surgery: Three-year retrospective evaluation of 50 consecutive cases. Int J Oral Maxillofac Implants 8:388-99, 1993.
12. Becker W, Dahlin C, et al, The use of ePTFE barrier membranes for bone promotion around titanium implants placed into extraction sockets: A prospective multicenter study. Int J Oral Maxillofac Implants 9:31-40, 1994.
13. Wilson TG, Schenk R, et al, Implants placed in immediate extraction sites: A report of histologic and histometric analyses of human biopsies. Int J Oral Maxillofac Implants 13:333-41, 1998.
14. Ivanoff C-J, Sennerby L, Lekholm U, Influence of initial implant integration of titanium implants. An experimental study in rabbits. Clin Oral Impl Res 7:120-7, 1996.
15. Kohal RJ, Hurzeler MB, et al, Custom-made root analogue titanium implants placed into extraction sockets. An experimental study in monkeys. Clin Oral Impl Res 8:386-92, 1997.
16. Lundgren D, Rylander H, et al, Healing-in of root analogue titanium implants placed in extraction sockets: An experimental study in the beagle dogs. Clin Oral Implants Res 3:136-44, 1992.
17. Todescan R, Pilliar RM, Melcher AH, A small animal model for investigating endosseous dental implants: Effect of graft materials on healing endosseous, porous-surfaced implants placed in a fresh extraction socket. Int J Oral Maxillofac Implants 2:217-23, 1987.
18. Becker W, Lynch SE, et al, A comparison of ePTFE membranes alone or in combination with platelet-derived growth factors and insulin-like growth factor-1 or demineralized freeze-dried bone in promoting bone formation around immediate extraction socket implants. J Periodontal 63:929-40, 1992..
19. Wilson TG, Guided tissue regeneration around dental implants in immediate and recent extraction sites: Initial observations. Int J Periodont Restorative Dent 12:184-93, 1992.
20. Lang NP, Bragger U, et al, Immediate transmucosal implants using the principle of guided tissue regeneration (I). Rationale, clinical procedures and 30 month results. Clin Oral Implants Res 5:154-63, 1994.
21. Gher ME, Quintero G, et al, Bone grafting and guided bone regeneration for immediate implants in humans. J Periodontal 65:881-91, 1994.
22. Sevor JJ, Meffert RM, Placement of implants into fresh extraction sites using a resorbable collagen membrane. Case reports. Practical Periodontology and Aesthetic Dentistry 4:35-41.
23. Celletti R, Davarpanah M, et al, Guided tissue regeneration around dental implants in immediate extraction sockets: Comparison of e-PTFE and a new titanium membrane. Int J Periodont Restorative Dent 14:243-53, 1994.
24. Becker W, Becker B, et al, Autogenous bone grafting of bone defects adjacent to implants placed into immediate extraction sockets in patients: A prospective study. Internat J Oral Maxillofac Implants 389-96, 1994.
25. Rosenquist B, A bioresorbable GTR membrane as occlusive barrier after placement of implants into fresh extraction sockets. A preliminary study. Submitted for publication, 1999.
26. Rosenquist B, Ahmed M, The immediate replacement of teeth by dental implants using homologous bone membranes to seal the sockets: Clinical and radiographic findings. Clin Oral Impl Res 11:572-82, 2000.
27. Cochran DL, Douglas HB, Augmentation of osseous tissue around nonsubmerged endosseous dental implants. Int J Periodontics Restorative Dent 13:506-19, 1993.
28. Bragger U, Hammerle CHF, Lang NP, Immediate transmucosal implants using the principle of guided tissue regeneration (II). A cross-sectional study comparing the clinical outcome 1 year after immediate and standard implant placement. Clin Oral Implants Res 7:268-76, 1996.
29. Cornelini R, Immediate Transmucosal Implant Placement: A Report of 2 Cases. Int J Periodontics Restorative Dent 20:199-206, 2000.
30. Schwartz-Arad D, Chaushu G, The Ways and Wherefores of Immediate Placement of Implants Into Fresh Extraction Sites: A Literature Review. J. Periodontol 10:915-23, 1997.
31. Chaushu G, Chaushu S, et al, Immediate loading of single-tooth implants: immediate versus non immediate implantation. A clinical report. Int J Oral Maxillofac Implants 16(2):267-72, 2001.
32. Jaffin RA, Kumar A, Berman C, Immediate loading of implants in partially and fully edentulous jaws: A series of 27 case reports. J Periodontol 71:833-8, 2000.
Legends
1. Figure 1a. Preoperative radiograph of tooth #4.
2. Figure 1b. Immediately after ITI implant placement.
3. Figure 1c. Two and one-half years after placement. Note that tooth #3 has endodontic pathology (Implant prosthetics by James M. Herron, DDS, Woodland Hills, Calif.).
4. Figure 2. Close adaptation of an implant to the crestal socket wall, within 1.5 mm.
5. Figure 3a. Preoperative view of tooth #25.
6. Figure 3b. ITI narrow neck implant immediately after placement.
7. Figure 3c. Six months after placement (Implant prosthetics by Gregory W. Holve, DDS, valley Village, Calif.).
8. Figure 4. Microsurgical scalpel (top) and periotome (bottom) can be used to help extract teeth.
9. Figures 5a through e. Implants are placed in extraction sites and extraction defects. Note that implants are placed at palatal aspect of the sockets with no pressure on the buccal place.
10. Figure 5g. The implants at uncovering.
11. Figure 5h. The final restorations.
12. Figures 6a through d. No. 11 is fractured, and #10 has irreversible mobility due to traumatic injury, which prohibits the replacement of the fixed bridge #11-15.
13. Figures 6e through g. Implants are placed in the extraction sites of #10 and #11 and in the #12 and #13 healed sites.
14. Figures 6h through k. The final implant restoration showing excellent preservation of the gingival form and no difference on the radiographs between the implants in the immediate and healed sites.
15. Figure 7a. Preoperative radiograph.
16. Figure 7b. Immediately after placement of ITI 4.8 mm implant.
17. Figure 7c. Ten months postoperative radiograph (Implant prosthetics by David M. Campbell, DDS, Woodland Hills, Calif.).
18. Figures 8a and b. Preoperative photo and radiograph showing #9 with a vertical fracture.
19. Figure 8c. A wide-diameter root form implant is placed, which reduces the distance between the socket walls and the implant.
20. Figures 8d and e. Two resorbable collagen membranes are placed, one on the buccal because of a narrow buccal late defect and one covering the implant, eliminating the need for primary closure.
21. Figure 8f. Healing at five weeks with preservation of gingival papillae.
22. Figure 8g. Temporary restoration helping shape the gingival form.
23. Figures 8h through j. The final restoration one year after completion.
24. Figure 9a. Preoperative view of tooth #21.
25. Figure 9b. ITI implant immediately after placement.
26. Figure 9c. Four months after placement. Note bone healing around neck of the implant.
27. Figure 10a and b. No. 7 fractured and nonrestorable.
28. Figures 10c and d. No. 7 an immediate implant is placed.
29. Figures 10e and f. Final restoration exhibiting the same gingival form as the original tooth.
30. Figure 11a. Preoperative #8 with a fractured root.
31. Figure 11b. Implant placement #8.
32. Figure 11c. Surgical site sutured with minimal displacement of the interdental papillae.
33. Figure 11d. Radiograph of implant #8.
34. Figures 11e and f. Temporary removable appliance used to shape and support the gingival papillae.
35. Figure 11g. Healing cap placed.
36. Figure 11h. Final crown with maintenance of interdental gingival form.
37. Figure 12a. Radiograph #8 shows a large radiolucency associated with a root fracture that precludes immediate implant placement.
38. Figure 12b through d. Extraction and augmentation of the socket.
39. Figures 12e and f. Healing and tissue support from the removable appliance.
40. Figures 12g through i. Implant placement eight months later.
41. Figure 12j. Implant site and uncovering.
42. Figures 12k and l. Implant restored with temporary crown 12 months from extraction. The two-stage approach takes considerably more time and more steps than immediate placement.
43. Figure 13a. Preoperative radiograph. Tooth #6 was not a good candidate for an immediate implant because the root fracture had caused too much vertical and horizontal bone loss on the facial bone.
44. Figure 13b. Preoperative photograph.
45. Figure 13c. Surgical view of missing facial bone.
46. Figure 13d. Photograph of extracted tooth.
Copyright Journal of the California Dental Association. Vol. 30, No. 5, May 2002.
Reprinted with permission.
Single Tooth Replacement_
An Illustration and Rationale
By Richard K. Rounsavelle, DDS
Abstract: This article demonstrates a method for the replacement of a single missing tooth with a dental implant system that can simply and easily be incorporated into a general practice. Recent innovations in implant abutment design and impression procedures have resulted in a technique that is very similar to traditional crown and bridge procedures. This article describes a step-by-step protocol for the restoration of a single missing tooth with an implant-borne, cemented crown.
The replacement of diseased natural tooth substance with an optimal material is the essence of restorative dentistry. The restoration should be durable, be reasonably esthetic, and require minimally invasive procedures. Dental schools have taught the art and science of partial coverage cast gold restorations (Figures 1a and b) with the ultimate intent of conserving healthy tooth structure. The implant-borne single tooth replacement, like the partial gold casting, embodies the principle of tooth conservation which all dentists should espouse in serving their patients.
With an implant, the adjacent teeth, when healthy, need no longer be prepared solely for the purpose of providing support for a fixed bridge. On occasion, every dentist has seen a formerly healthy tooth progress through a series of destructive events following restoration for crown retainers. This scenario is now avoidable.
The ITI Solid Abutment System, described herein, heralded a breakthrough in simplifying the restorative process. Dental implants, formerly the province of a few specialists, now may be routinely accomplished by all general dentists.
A team approach is best for treating implant patients. The general practitioner should refer his or her patients to a qualified specialist for surgical placement of implant fixtures, along with bone grafting and soft-tissue manipulation where indicated. In consultation with a surgeon, the G.P. will share the responsibility for evaluating such factors as medical history, availability of supporting bone, soft tissue contours, occlusion, and cosmetics. The use of mounted study casts with a diagnostic wax-up of the replacement tooth greatly facilitates the shared evaluation of a given case. In addition to the wax-up, the G.P. may also provide guidance as to implant location by using a surgical stent or template for surgical implant positioning. This appliance may take many forms, but for single tooth replacement, a tooth-borne device is usually most appropriate. This device may transfer from the diagnostic wax-up the facial or lingual anatomy of the proposed final restoration, depending on the surgeon's preference. This transfer conveys to the surgeon the G.P.'s intent for the final restoration at the time of implant placement (Figure 2).
After the implant has "osseointegrated," or united to the surrounding bone, the patient is ready for restoration. The technique described involves a solid abutment, which is analogous to a tooth preparation (Figure 3); an impression cap and cylinder; and a laboratory replica of the abutment.
First, one places the white impression cap over the implant collar (Figure 4). This impression coping eliminates the need for tissue retraction and, therefore, local anesthesia. To be certain that complete seating has occurred, one should rotate the cap while viewing it from an occlusal direction. If the cap rotates without dislodging and the abutment appears to be centered, it is seated properly. Seating requires firm pressure and, when achieved, will result in a palpable "click" (Figure 5).
Next, the positioning cylinder (Figure 6) is placed into the impression cap. The trick here is to view the abutment again from an occlusal perspective to orient the flat section of the abutment and match it to the corresponding flat area of the positioning cylinder. It, too, will seat with firm pressure and must go completely into place (Figure 7).
One is then ready to take the impression. The best impression material to use is the most rigid: vinyl polysiloxane. Polyether and polysulfide also work well. Nonrigid materials, such as hydrocolloid, are contraindicated. One should be sure to block out any large undercuts created by teeth within the arch. Syringe hydrocolloid works well for blocking.
Figure 1a. Figure 1b.
Figures 1a and b. Partial gold coverage can be both conservative and esthetic.
Figure 2. Implant positioning guide for single tooth with lingual acrylic of replacement
tooth removed.
Figure 3. Standard solid abutment
torqued into ITI implant fixture.
Figure 4. Standard abutment
impression cap.
Figure 5. Impression cap in place over abutment.
Figure 6. Positioning cylinder for 5.5 mm solid abutment.
Figure 7. Positioning cylinder seated into impression cap.
Figure 8. Impression cap/positioning cylinder imbedded within final impression.
Figure 9. Analog of a 5.5 mm solid abutment.
Figure 10. Analog seated into place in the impression cap/positioning cylinder assembly.
Figure 11. Final laboratory cast for crown fabrication.
Figure 12. Plastic coping for laboratory procedures (seated on analog).
Figure 13. Protective cap for temporization.
Figure 14. Plastic coping shortened and air abraded for inclusion in an acrylic provisional crown.
Figure 15. Modified copings seated on solid abutment.
Figure 16a. Acrylic filled shell seated over modified copings.
Figure 16b. Shell with acrylic and copings incorporated.
One should inject and place the tray as for any other crown impression. The cap and cylinder assembly should lift off the abutment and be embedded within the impression (Figure 8).
The actual "prep" or abutment that the lab will use is called an analog or abutment replica (Figure 9). This is a small metal component that one must next mate to the impression component assembly. Again, one carefully matches the flat side of the analog with the flat side of the positioning cylinder and firmly pushes it into place. If the analog does not snap into the impression cap, it is not seated completely (Figures 10 and 11).
The impression is now ready for the lab. The lab will use a prefabricated plastic coping (Figure 12) to act as a base onto which wax is added to create the appropriate contour from which the crown is completed via conventional procedures.
The options for placing a temporary crown depend upon the patient and the situation. A very simple approach is to use temporary cement to place a temporary protective cap available from the manufacturer (Figure 13). If the patient requires a more esthetic temporary crown, one may modify a plastic coping (the same one used in the laboratory phase) and incorporate the coping with acrylic resin into a crown form or clear plastic shell. This latter technique requires more chair time but is greatly appreciated by a patient who needs a tooth and has been without a fixed replacement. The procedure for this is as follows:
First, one shortens, scores, and air abrades the coping in the lab. Then one seats the coping until it snaps into place over the abutment (Figure 15). The crown form or clear matrix filled with acrylic is allowed to set completely on the coping (Figures 16a and b). It is very important to remove all acrylic from any undercuts prior to the final set. The coping "over-crown" is then taken to the lab; and, very carefully, using the salt and pepper technique, one fills in the spaces between the acrylic and the margin of the coping (Figure 17). Once this is achieved, one may finish and polish to create the final crown contour and emergence profile. The final provisional must snap into place on the abutment to prevent soft tissue encroachment over the implant collar. To achieve this fit, one must remove a small amount of acrylic from the occlusal aspect of the provisional internally with a straight fissure lab bur. One then cements with temporary cement and thoroughly removes any gingival excess, as it commonly lodges just below the implant collar.
Figure 17. Addition of acrylic to establish contour and marginal adaptation.
Figure 18. Final first premolar restoration cemented to place.
Figure 20. ITI Wide Neck abutment.
Figure 19. Partial displacement of excess cement using laboratory analog prior to cementation.
Figure 21. Final restoration showing a more favorable emergence contour achievable with wider implant (tooth #31 was periodontally compromised).
Figures 22, 23. Very narrow restorations on the ITI Narrow Neck abutments.
The beauty of this implant system is its simplicity and similarity to conventional crown and bridge procedures: One tries the crown in place, adjusts contacts and occlusion, and cements. The following are helpful hints on adjusting these crowns:
If the implant collar extends more than 2 mm subgingivally, one may minimize excess cement by displacing it with an analog prior to final cementing of the crown (Figure 19). When a large volume of cement is removed extraorally, the clean-up of set cement from the subgingival area is greatly facilitated.
There are several abutments available to deal with other restorative situations and locations. For example, when the missing tooth has sufficient bone and mesiodistal dimensions, as in the molar region, a larger diameter implant with a wider platform is indicated (Figure 20). This increased diameter affords significantly greater implant surface area for osseointegration and a more-ideal emergence profile for the final restoration (Figure 21). A larger bearing area better distributes the load of posterior occlusion. The components and procedures are identical to those used with the standard abutment. Due to the posterior location of most wide-body implants, one would usually temporize with a simple protection cap. Cementation considerations are similar to the standard abutment; however, because these abutments are often shorter than the standard due to reduced interocclusal distance, the additional retention afforded by stronger cement may be needed. Retention may also be enhanced by a lateral set screw.
A narrow implant and abutment can be used for mandibular incisors, maxillary lateral incisors, and some small premolar areas (Figures 22, 23).
There will be situations in which the implant collar (the finish line of the restoration) is intentionally located deeply subgingivally to help the restorative dentist develop the optimum esthetics of the final restoration. This usually occurs in the anterior region and the mesial aspect of the maxillary first premolar. If the final crown margin extends to this deep margin location, a significant complication may occur during cementation. Excess cement can be driven over, around, and under the implant collar during crown placement. This subgingival cement can be very difficult, if not impossible, to remove completely; and these retained cement fragments may cause considerable soft tissue inflammation and infection.
The best way to avoid "deep" finish lines affecting implant-borne anterior crowns is to use the custom abutment (Figure 24). The clinician may then elevate the margin to a more coronal location. With the finish line, and thus the excess cement, made more accessible, the complication of excess cement removal is greatly reduced. There are other advantages of using the custom abutment in the anterior teeth. The long axis of the implant may be in a different inclination than that of the final crown. The custom abutment can correct this discrepancy in both labiolingual and mesiodistal directions. The resulting contour enhances tissue health and architecture for an optimum esthetic result (Figure 25).
Figure 24. Soft tissue that has been
sculpted by a properly contoured provisional crown.
Figure 25. Provisional restoration veneered with microfill composite resin.
Figure 26. Ceramo-metal custom abutment on tooth #8.
Figure 27. Final ceramo-metal crown cemented on the custom abutment shown in Figure
24.
To maximize the esthetic result, one should sculpt the surrounding tissues with a
carefully made provisional crown prior to the final impressions (Figure 26). The
technique that uses a plastic coping and stock crown or prefabricated clear shell works
well. For the cosmetically demanding patient, one may modify the shade of the provisional
crown by removing approximately 1 mm of labial acrylic and directly bonding microfill
composite resin to the acrylic surface (Figure 27).
One may fabricate the custom abutment by casting metal to a stock screw-retained abutment. This custom abutment is secured to the implant with the appropriate screw, and the crown is cemented onto it.
This article has described a technique that will greatly facilitate the incorporation of osseointegrated dental implant restorative treatment into the general practitioner's routine procedures. This technique is just a beginning. The principle and procedures discussed can be expanded to apply to a wide variety of more-involved restorative situations that may be more complicated. As one's experience and skill increases, the way one thinks about cases with missing teeth will change considerably. The care one provides to patients will progress to a higher level, a level that fully respects the ideals of mentors who encouraged their students to preserve tooth structure with conservative gold restorations.
Author
Richard K. Rounsavelle, DDS, is a general dentist in Torrance, Calif. He is also a member of CDA's Council on Scientific Sessions.
Copyright California Dental Association Journal. Vol. 29, No. 11, Nov. 2001.
Reprinted with permission.
Legends
1. Figures 1a and b. Partial gold coverage can be both conservative and esthetic.
2. Figure 2. Implant positioning guide for single tooth with lingual acrylic of replacement tooth removed.
3. Figure 3. Standard solid abutment torqued into ITI implant fixture.
4. Figure 4. Standard abutment impression cap.
5. Figure 5. Impression cap in place over abutment.
6. Figure 6. Positioning cylinder for 5.5 mm solid abutment.
7. Figure 7. Positioning cylinder seated into impression cap.
8. Figure 8. Impression cap/positioning cylinder imbedded within final impression.
9. Figure 9. Analog of a 5.5 mm solid abutment.
10. Figure 10. Analog seated into place in the impression cap/positioning cylinder assembly.
11. Figure 11. Final laboratory cast for crown fabrication.
12. Figure 12. Plastic coping for laboratory procedures (seated on analog).
13. Figure 13. Protective cap for temporization.
14. Figure 14. Plastic coping shortened and air abraded for inclusion in an acrylic provisional crown.
15. Figure 15. Modified copings seated on solid abutment.
16. Figure 16a. Acrylic filled shell seated over modified copings.
17. Figure 16b. Shell with acrylic and copings incorporated.
18. Figure 17. Addition of acrylic to establish contour and marginal adaptation.
19. Figure 18. Final first premolar restoration cemented to place.
20. Figure 19. Partial displacement of excess cement using laboratory analog prior to cementation.
21. Figure 20. ITI Wide Neck abutment.
22. Figure 21. Final restoration showing a more favorable emergence contour achievable with widerimplant (Tooth #31 was periodontally compromised).
23. Figures 22, 23. Very narrow restorations on the ITI Narrow Neck abutments.
24. Figure 24. Soft tissue that has been sculpted by a properly contoured provisional crown.
25. Figure 25. Provisional restoration veneered with microfill composite resin.
26. Figure 26. Ceramo-metal custom abutment on tooth #8.
27. Figure 27. Final ceramo-metal crown cemented on the custom abutment shown in Figure 24.
Experiences With
Fixed ImplantSupported Prostheses
By Gun Sandberg, RDH, MSci; Torsten Stenberg, DDS, PhD; and Karin Wikblad, PhD
Abstract
Purpose. This study investigated patients' perceptions of fixed implantsupported prostheses (ISP) in totally edentulous jaws in order to obtain a broader base for patient information.
Methods. A total of 135 patients who had received prosthetic rehabilitation treatment responded to a questionnaire on oral functions, speech, oral selfcare, esthetics, lifestyle changes and selfconfidence, oral comfort, and overall satisfaction with ISP. The patients also listed positive and negative experiences with the ISP.
Results. Most patients (97%) reported overall satisfaction. Chewing ability was rated as good or very good by all but one (99.3%). Twentysix patients (19.6%) identified bruxing and clenching habits; these were significantly younger than those free from problems. Phonetic problems were reported by 32.8% after insertion, with 18.6% (eight patients) having remaining problems after seven to 10 years. Most of the patients (87.2%) found it easy to clean the prosthesis. Improved lifestyle after ISP insertion was reported by 75% and increased selfconfidence by 82% of the patients. Improvements were especially perceptible in social situations that involved conversation or eating. None of the measured variables was related to duration of having ISP.
Conclusions. The patients' experiences in this study lasted over a period of 10 years, thus their positive and negative aspects can serve as information support for dentistry to enable future ISP patients to make appropriate choices. The information could be made available to patients by including in a patienttargeted booklet.
Keywords. Implantsupported prosthesis, patient satisfaction, oral function, oral self care, esthetics, lifestyle, selfconfidence, patient information.
Today edentulous patients can choose among several types of tooth replacement treatment. However, to make the right choice, they must have adequate information. Technical information is easy to provide but is not sufficient for decision making. There is a need for complementary information on patients' satisfaction and experiences in wearing a certain type of prosthesis.
The aim of the current study was therefore, to document patient experiences and perceptions of wearing implantsupported prostheses (ISP) over a period of 10 years in order to obtain an extended knowledge base for patient information.
Earlier, the only treatment of toothlessness was a removable denture. A new era in tooth replacement treatment began when Brånemark published the results of 10 years' treatment with titanium implantsupported dental prostheses in more than 200 patients.1 Since its introduction in 1965, the Brånemark implant system has shown a high rate of success for ISP in totally edentulous jaws.7
Successful ISP treatment is dependent on biological, psychosocial, functional, technical, and constructional factors.5 Jemt followed, in a retrospective study, 391 edentulous patients consecutively treated with ISP from the time of prostheses placement to the first annual checkup.6 The overall success rate was 98.1% and 99.5% for the implants.
Oral Functions
Over a threeyear period, oral functioning in patients rehabilitated by maxillary ISPs was evaluated in a longitudinal investigation.7 Additionally, a questionnaire solicited patients' subjective evaluation of the effect of the therapy. All patients were pleased with the oral rehabilitation, and the ISP treatment led to increased oral functions. e.g., chewing comfort.
In a retrospective study, patient satisfaction and maintenance issues for 156 patients were evaluated.7 Patients were asked to rate oral functions and overall satisfaction by use of visual analogue scales. Information on maintenance was collected from dental records. Despite a number of repairs needed within the first year, patients indicated a high level of overall satisfaction with their oral functions.
In a threeyear followup study patients participated in a survey.9 Patients' opinions were obtained by questionnaires using sixgrade scales ranking from negative to positive or
never to always. The patients were given the questionnaire at the first recall interval within four months, and again after three years to elucidate the long-term effects of the reconstructions. The patients were very satisfied with the oral functions, and chewing ability improved significantly during the three years after treatment. Nearly all patients said that they would undergo the treatment again or recommend it to others.
Speech and Phonetics
Haraldsson investigated 19 randomly selected patients and found that about half of the edentulous patients experienced speech difficulties immediately after having had ISP, but mainly during the first weeks or months after treatment.'° Twentyone individuals treated with fixed ISP in the maxilla were evaluated in two studies.2 In one study, registrations were made when the patients wore complete removable dentures in the upper jaw, and three to six months after they had been treated with ISPs in the maxilla. These patients were reexamined after three years.12 The results indicated that, after initial problems, 94% of the individuals considered themselves to be free from speech problems at a three-year followup, while 6% did not.
Jemt reported clinical problems encountered during a fiveyear period for a group of 76 patients treated with fixed ISPs.3 Speech problems was the most frequent complaint during the first year. When Jemt studied 391 edentulous patients treated with ISP during one year from the time of prostheses placement, he stated that problems involving speech were obviously related to time.6 Onethird of the patients had phonetic problems immediately after treatment, but only 13% had remaining problems after one year. The patients' adaptation by increasing lip pressure to prevent air leakage reduced the speech problems.
Oral SelfCare
Difficulties in cleaning the prosthesis also seem to be a problem, and patients have reported less satisfaction with the oral selfcare associated with the prostheses. Walton's retrospective study on patient satisfaction and maintenance found a high level of overall satisfaction with the ISPs. The only exception was limited satisfaction with the cleansibility of the fixed ISPs.
Psychological and Social Factors
Improved psychological and social functions, quality of life, self-confidence, and satisfaction of patients after insertion of ISP have been reported. Twentysix patients were examined pre and postoperatively after three months, and again after two years, in two controlled studies.14, 15 The majority of these stated that their lives had improved significantly; that they had regained selfconfidence; and that in contrast to patients having
worn a conventional removable denture, they accepted the ISP as a part of themselves. These results have been supported by others who have stated that qualityoflife factors associated with ISP may be important for understanding the success of implantology.15, 16 A survey study that compared status before and after ISP therapy suggested that patients' attitudes toward their dental health improved significantly after treatment with ISPs.17 Harle studied 46 female patients in a survey to assess the impact of ISP and conventional removable dentures on relative health status.18 The data demonstrated that, for some patients, there were clinically important advantages of ISP in terms of improved physical, psychological, and social functioning.
Very little is known, however, about patients' longterm experiences, and some of the studies mentioned above included few subjects. Thus, a larger study was needed to measure patients' experiences over a longer period of time to be able to give impartial information to patients choosing a treatment from among options.
A crosssectional design was used and data were collected from dental records and by use of questionnaires mailed to patients who had received fixed ISP during a 10-year period.
Sample
To control for constructional and technical factors, only patients treated by one specific prosthodontist at a prosthodontic clinic in Sweden during a 10year period were selected. A total of 148 patients had received prosthetic rehabilitation treatment with fixed ISP during the 10year period from this prosthodontist. The group consisted of 60 males and 88 females ranging in age from 36 to 90 years (mean age 66.9 years, SD 10.2).
Measurements
A modified version of questionnaires shown to have good validity and reliability in earlier epidemiological studies was used in the data collection.7, 19 The modified questionnaire also was tested in a pilot study among a group of adult and elderly people. It consisted of 29 items in the following areas.
Besides data from the questionnaire, the following data were collected from the dental records:
Procedure
Data were collected by a dental hygienist. Names and addresses of the 148 patients were obtained from the prosthodontic clinic. The prosthodontist who had treated the patients did not participate in the data collection. Questionnaires were mailed to the 148 patients, along with a letter informing them about the purpose of the study and its voluntary nature. After one reminder, 135 (91.2%) of the patients responded.
Dropout analysis was undertaken to ascertain the reason for lack of response by 13 of the subjects. Of them, six had died, two had been admitted to hospital, two felt themselves too old and too tired to fill in the questionnaire, one had forgotten to fill in the questionnaire, and two could not be reached.
Data Analysis
The computer program Statview 4.5 was used for all data analyses. To isolate time related differences, the sample was divided into four subgroups: one to two, three to four, five to six, and seven to 10 years after ISP insertion. Depending on data type, results are presented as median values with range or mean values with standard deviations. Answers to openended questions were categorized with reference to similarities and differences in the answers. Group comparisons were made by use of ANOVA for continuous data and c2 tests for discontinuous: p< 0.05 was regarded as statistically significant.
Demographic and Clinical Characteristics
Responses were received from 135 patients, 53 males and 82 females, ranging in age from 44 to 90, with an average of 67 years (SD 9.7). A total of 768 implants had been inserted, 38.9% in the maxilla and 61.1% in the mandible. Reasons for ISP selection over removable dentures were patient preference in 34% and functional problems (e.g., prosthesis fits loosely, chewing and speech difficulties) in 63.3% of the patients. In the remaining 2.7%, the reason was unknown. Seventyone (52.7%) of the patients were totally edentulous in both jaws and wore conventional removable prostheses; 23.3% wore removable prostheses in one jaw and retained their own teeth in the other. Twentyfour percent had caries and periodontitis without any earlier experiences of wearing prostheses. The patients had ISP for 4.8 years as a mean (SD 2.5 years, range one to 10 years). To be able to detect problems that may be timerelated, the patients were divided into four groups according to length of time wearing ISP. Demographic and clinical characteristics in the four groups are shown in Table I.
Oral Functions
The questions in this area included the ability to masticate food and types of food that were difficult for the patient to masticate. Chewing ability was rated as good or very good by all patients but one (99.3%). Most (86.4%) reported that they ate all types of food. Some food, however, was so difficult to chew that 13.6% avoided it. Food that was avoided included hard bread, stringy meat, raw vegetables, apples, and nuts. There were no differences in chewing ability among the four subgroups (Table II). Neither were age (F=0.25, DF=2/130, p= 0.8) or gender differences (c2=0.87, DF=2, p=0.65) found in this respect.
Bruxing and clenching habits were identified by 26 patients (19.6%), and 10 (7.6%) experienced a sense of fatigue or stiffness in the temporomandibular joint. The patients who reported bruxing and clenching habits were significantly younger (61.5 years. SD 9.5) than those free from such problems (68.7 years, SD 9.5; F=5.75, df=2/130,p= 0.004), but no significant differences were found that could be related to time wearing ISP (Table II.). Twentyfive patients were not aware of whether they had bruxing and clenching habits.
Table I. Demographic and Clinical Characteristics of 135 Patients in Relation to Length of Time Wearing ISP
Length of time wearing ISP
Characteristics 12 years 3-4 years 5- 6 years 710 years
Age (years±SD) 66.3±8.6 67.6±9.0 66.4±11.6 67.1.±9.9
Male/Female (number) 8/15 24/25 12/20 9/22
ISP location:
maxillary (number) 6 15 8 5
mandibular (number) 15 28 20 19
both jaws (number) 2 6 4 7
Length of time
wearing ISP (years±SD) 1.6±0.5 3.47±0.5 5.41±.05 8.58±0.92
Speech and Phonetics
Fortythree (32.8%) patients encountered phonetic problems after implant insertion, with eight (18.6%) having remaining problems after seven to 10 years. Differences were found between maxillary and mandibular prostheses, in that those with maxillary prostheses reported significantly more speech problems (c2= l 9.36, DF=27 p=0.000 1). Speech problems did not significantly decrease with time lapsed since treatment (Table II). The most common problem was pronouncing the esound and variations such as sj, sch, ski, st, and str. Other difficult sounds were b, d, f, j, and r. Respondents commented in the following way regarding their difficulties.
When asked about their conversation with other people, 69.4% reported that conversation was easier to manage after ISP, 28.2% found no difference compared to the time prior to insertion of ISP, and 2.4% found it more difficult than before to speak with others. This did not seem to be related to time lapsed since ISP insertion (Table II). No age (F=0.2, DF=2/121, p=0.82) or gender differences (c2=0.16, DF=2, p=0.69) were found.
Oral SelfCare
One hundred thirty patients (97.7%) stated that they had received adequate information on taking care of the prostheses. Most of the patients (87.2%) found it easy to clean the prostheses; difficulties were reported by 12.8%. Cleaning problems did not decrease significantly with length of time with ISP (Table II). Age (F=0.78, DF=2/130, p=0.46) or gender differences (c2=0.36, DF=2, p=0.84) were not found.
Esthetics
Most patients (94.3%) indicated satisfaction with the esthetics of their ISP, 5.2% were neither satisfied nor dissatisfied, and 0.5% reported dissatisfaction. Significant differences were not found among the four groups (Table III).
Examples of patient's comments are
When asked about their overall appearance, 49.2% of the patients reported an improvement, 44.6% answered that the overall appearance was neither better nor worse than before the insertion, and eight individuals (6.2%) were of the opinion that their overall appearance had worsened compared to the time prior to ISP insertion. Satisfaction or dissatisfaction with esthetics did not correlate with the length of time they had ISP (Table III). No age (F=0.91, DF=3/128,p=0.44) or gender differences (c2=2.73. DF=3, p=0.44) were found.
Table II. Percentage of Patients Reporting Absence of Problems With Oral Functions, Speech, and Oral Self-Care (n=135)
Length of time wearing ISP
variables % of n=23 % of n=49 % of n=32 % of n=31 Statistics
Oral functions
Good chewing ability 100.0 100.0 96.8 100.0 c2(3)=3.32 p=0.3
Can eat all kinds of food 86.4 87.5 87.1 83.9 c2(3)=.23 p=0.9
Absence of bruxing/clenching* 81.0 75.0 71.4 79.0 c2(3)=0.71 p=0.9
Absence of fatigue/stiffness 86.4 95.9 86.7 96.8 c2(3)=4.27 p=0.2
Speech
Absence of phonetic problems 56.5 68.1 67.7 73.3 c2(3)1.72 p=0.6
Conversation easier 76.2 66.0 69.0 70.4 c2(3)=0.73 p=0.9
Oral self-care
Absence of cleaning problems 82.6. 87.5 87.1 93.6 c2(3)=1.57 p=0.7
*Twenty-five patients were not aware of whether they had bruxing and clenching habits.
Life-Style Changes and Self-Confidence
Improvement in lifestyle related to the ISP was reported by 74.2% of the patients while 25% did not experience any such changes and one individual experienced deterioration. In a further question, patients were asked if they tended to cover the mouth during social interactions. One hundred nineteen patients (90.8%) reported that they never did this, whereas eight (6.1%) said that they sometimes did, and four (3.1% ) answered that they
often did. When asked about the level of self-confidence they felt since the insertion of the ISP, 82.4% identified an improvement compared with the time prior to ISP insertion. Twenty-three (17.6%) did not experience any changes in self-confidence and no correlation was found with length of time wearing ISP (Table III). No age or gender differences were found.
Patients commented that they had stronger self-confidence and a renewed enthusiasm for life. Comments included
Table III. Percentage of patients reporting positive influence of ISP on esthetics, improvement in life-style and self-confidence (n= 135)
Length of time wearing lSP
Measured 1-2 years 3-4 years 5-6 years 7-10 years Statistics variables % of n=23 % of n=49 % of n=32 % of n=31
Satisfied with
esthetics of ISP 95.7 97.9 90.3 90.3 c2(3)=2.97 p=0.4
Improved overall 50.0 51.0 44.8 50.0 c2(3)=0.3
appearance p=0.96
Improved lifestyle 77.3 70.2 79.3 73.3 c2(3)=0.91 p=0.8
Never covering the mouth 87.0 93.6 93.3 87.1 c2(3)=1.6
during social interactions p=0.7
Improved self-confidence 91.3 77.1 83.3 83.3 c2(3)=2.23 p=0.5
Oral Comfort
Patients demonstrated high level of oral comfort on the 10-point VAS scale (=9.2; SD 1.3). Both females (53. l %) and males (67.3%) rated their oral comfort after ISP insertion higher compared to the time prior to insertion. Comments like "lt has been good all the time" and "there is no difference"' were frequent in the open-ended questions related to oral comfort.
Overall Satisfaction
One hundred twenty-nine patients (97.7%) reported that they were generally satisfied, two that they were neither satisfied nor dissatisfied, and one patient felt dissatisfied with ISP. No significant relation was found between satisfaction and length of time wearing ISPs (c2=9, p=0.5). Examples of patient comments in this area:
The responses to the open-ended questions regarding the most positive and the most negative experiences with the ISP were categorized as follows (the categories are exemplified by patient quotations).
Positive aspects:
a. Self-confidence/Safety
b. Function
- No problems with chewing.
- I don't have sores or pain in my mouth anymore.
c. Appearance
- Wonderful to have teeth in my mouth.
- My teeth are so beautiful.
d. Psychosocial
- I'm not afraid of having dinner at a restaurant.
- I'm able to live a normal life again.
- To lose one's teeth is a tragedy—now the joy of living has returned.
The most frequent positive comments included increased self-confidence and that the connection of the prosthesis to implants gave increased safety.
Negative aspects:
a. The treatment
- The treatment was hard and l was terrified that it could turn out to be a failure.
- It was a hard and tedious procedure.
b. Cleaning
- It's hard work to keep them clean.
- The cleaning is time consuming.
c. Speech
- I cannot pronounce certain words.
d. Appearance
e. Economy
_ It is too expensive.
f. Technical problems
g. Miscellaneous problems
Thirtytwo patients reported that they were not able to identify any negative aspects of ISP. Most negative comments related to the surgery in itself and particularly the periods between the different stages in the treatment. Ten patients felt that the ISP had a negative impact on their appearance, e.g., because of wrong length and wrong color of the teeth.
To the question "If you get the opportunity to choose the type of prosthesis today, would you make the same choice?" 94.6% of the patients answered "yes."
In order to obtain an extended knowledge base for patient information, the present study focused on the importance of evaluating patients' longterm experiences and perceptions about their implant-supported prostheses (ISP). Responses were received from 135 patients (91.2%) who had been treated with implant therapy in totally edentulous jaws during a 10year period. These patients' own opinions—their positive and negative findings—may serve as support for impartial information to others when they have to choose a type of treatment.
Most of the patients stated that prior to the ISP insertion they had had oral problems often and for a long time, and the main reason for ISP selection was to alleviate the functional problems experienced.
The patients' chewing ability improved after insertion of ISP and remained good throughout the 10 years. Other studies also have found similar improvement of oral function after insertion.79 All patients but one (99.3%) rated chewing ability as good or very good, and most of them (86.4%) could chew all types of food. A sense of fatigue was reported in 7.6%, and bruxing and clenching habits were present in onefifth of the patients, and were significantly more frequent in younger patients than in the elderly.
Phonetic problems were encountered by onethird of the patients but decreased over time, and one-fourth had remaining problems. After seven to 10 years, 73. 3% of the patients in this study reported absence of phonetic problems. The problems were significantly more prominent in patients with maxillary prostheses. This is in accordance with other findings.16, 12 Jemt found that speech problems were the most frequent ISP
complication in maxillary ISP during the first year after insertion.13
Others also have reported speech problems directly after ISP insertion.6, 10, 12 The problems decreased to l3% after one year in the study by Jemt.6 Lundqvist, et al. on the other hand, found that, after initial problems, 94% considered themselves free from speech problems after three years with ISP.12 In this study eight of the patients ( 18.6%) had remaining problems after seven to 10 years. In the subgroups three to four years and five to six years respectively, 31.9% and 32.3% of the patients had remaining problems. Those figures are much higher than in other studies.
Lundqvist studied 21 subjects for three years, and Jemt 391 patients during one year. Thus, the results of those studies cannot be compared directly to this study. The method of this study, with the clinician not addressing the patients or signing the questionnaires, probably made the patients more willing to give impartial answers.
Respondents commented on their difficulties in response to the openended questions, and the most common problem was pronouncing the ssound. This was in accordance with earlier findings.6, 12 When asked about their conversation with other people, 69.4% reported that it was easier to speak with others after ISP insertion than before. This did not seem to be related to time lapsed since ISP insertion.
Most patients (97.7%) reported that the information received regarding selfcare directions was adequate. In addition, 87.2% found it easy to perform selfcare procedures. This result is not in accordance with data obtained by Walton, who found that cleaning difficulties were experienced by 44% of subjects.8 All patients in this study received dental hygiene care prior to and after the ISP insertion; thus, the diverging results could be due to quality of instructions given. It might be of interest to investigate this aspect further.
Very high levels of oral comfort after ISP insertion (x=9.2 on a 10-point VAS scale) were reported. The tendency that oral comfort may increase with length of time wearing ISP is probably due to adaptation to the fixed ISP over time, and is perhaps also a matter of memory in that it was probably not possible to remember how the ISP had felt 10 years ago. Most patients reported satisfaction with the esthetics of their ISP, and only 1% was dissatisfied. Regarding general appearance, many of the patients reported positive opinions, and 94.3% were satisfied with the esthetics of the ISP. The tendency towards less satisfaction in patients who had received their fixed ISP many years ago can probably be explained by the need for repair and remaking of the fixed ISP, in some cases due to worn or discolored constructions. However, when asked about overall appearance 49.2% reported an improvement, and 44.6% indicated that their overall appearance was neither better nor worse than before ISP. The patients may have been aware of changes but not felt comfortable commenting on their own overall appearance.
Satisfaction or dissatisfaction with esthetics did not correlate with length of time wearing ISP.
Lifestyle improvement was reported by approximately 75% of the patients, and increased self-confidence by 82%. This was especially perceptible in social settings including conversation or eating. The positive changes in quality-of-life factors and confidence are supported by other studies.14-18
The overall effect variable indicated that the patients were satisfied (97.7%) with their ISP and is in accordance with earlier findings.9, 15, 18 The patients' negative comments in this study, even if they were few, suggest that dentistry still has some technical and information issues to address when providing individualized patient care. Kerschbaum suggested that the difficulty in addressing the question about satisfaction results from its multifactorial nature including biological, psychological, and technical factors; and the fact that a patient seldom has the opportunity to compare his or her treatment with relevant alternatives.5 The current study supports this approach, as a combination of variables was found to have an impact on the patient's level of satisfaction. Guckes, et al. suggested that future research should include outcome measures beyond implant prosthesis survival to assess more fully the practical impact of dental implants on the patient's oral health.20 It is, however, important to supply patients not only with technical information, but also with complementary information on what it is like to live with a certain type of ISP. This is an important area for dental hygienist involvement.
The results of this study about patients' experiences, positive and negative, can serve as information support for dentistry to enable potential ISP patients to make appropriate choices. The dental hygienist is, today to a greater extent than earlier, involved in the ISP treatment_above all before as well as after the technical treatment. Therefore, the dental hygienist needs to know of many aspects of patients' satisfaction and experiences in living with a certain type of prosthesis. To make the information available to patients, it could be included in a patient-targeted booklet. The booklet could include a list of quotations on positive and negative experiences, together with data on patients' experiences in wearing ISP.
Conclusions
A combination of variables was found to have an impact on the high level of satisfaction with ISP. This study encompasses 10 years of patient experiences; thus, their positive and negative experiences can serve as information support to enable future ISP patients to make appropriate choices. It is important to supply patients not only with technical information, but also with complementary information on living with a certain type of ISP. Such information could be made available to patients by the dental hygienist.
Acknowledgment
Funding was obtained from Dalarna Research Institute, Falun, Sweden. Gun Sandberg, RDH, MSci, is registered tutor at the dental hygiene program; and Karin Wikblad, PhD, is associate professor, and senior lecturer; both at Dalarna University College, Falun, Sweden. Torsten Stenberg, DDS, PhD, is prosthodontist and chief dentist in prosthodontics at Falun Center of Oral Rehabilitation, Department of Public Dental Health, County of Dalarna, Sweden.
References
1. Brånemark P-I, et al.: Osseointegrated implants in the treatment of the edentulous jaw. Experience from a 10 year period. Scand J Plast Reconstr Surg 1977;16:1-132.
2. Brånemark P-I Zarb G, Albrektsson B: Introduction to osseointegration. Osseointegration in Clinical Dentistry. (Chaps 1). Chicago, Quintessence Publ. Co, 1985.
3. Adeli R, et al.; A long-term follow-up study of osseointegrated implants in the treatment of totally edentulous jaws. Int J Oral Maxillofac Impl 1990-5:347-58.
4. Albrektsson T, Zarb G, Worthington P, Eriksson P: The long-term efficacy of currently used dental implants: A review and proposed criteria of success. Int J Oral Maxillofac Implants 1986;1: 11-25.
5. Kerschbaum T: Long-term prognosis of conventional prosthodontic restorations. In: Naert. Steenberghe v. Worthington (eds.): Osseointegration in Oral Rehabilitation. London, Quintessence Publishing Co.1993;3 3-49.
6. Jemt T: Failures and complications in 391 consecutive insert fixed prostheses supported by Brånemark implants in edentulous jaws. A study of treatment from time of prosthesis placement. Oral Maxillofac Implants.
7. Lundqvist S, Haraldson T: Oral function in patient's wearing fixed prosthesis on osseointegrated implants in the maxilla: 3-year follow-up study. Scand J Dent Res 1992; 100(5):279-83.
8. Walton JN, MacEntee Ml: Problems with prostheses on implants: A retrospective study. J Prosthet Dent 1994;71 :283 288.
9. DeBroyn H, Collaert H. Linden B, Björn, A: Patient's opinion and treatment outcome of fixed rehabilitation on Brånemark implants. A 3-year follow up study in private dental practices. Clin Oral Impl Res 1997;8:265-271.
10. Haraldson T, Carlsson GE: Bite force and oral function in patients with osseointegrated implant bridges. Scand J Dent Res 1977;36:200-208.
11. Lundqvist S, Lohmander-Agerskov A. Haraldson T: Speech before and after treatment with bridges on osseointegrated implants in the edentulous upper jaw. Clin Oral Impl Res 1992;3:57-62.
12. Lundqvist S, Haraldson T, Lindblad P: Speech in connection with maxillary fixed prostheses on osseointegrated implants: A three-year follow-up study. Clin Oral Impl Res 1992;3(4):176-80.
13. Jemt T: Fixed implant-supported prostheses in the edentulous maxilla. A five-year follow-up report. Clin Oral Implants Res 1994;5(3): 142-7.
14. Blomberg S, Lindkvist L: Psychological reactions to edentulousness and treatment with jawbone-anchored bridges. Acta Psychiatr Scand 1983;58:251 -262.
15. Blomberg S: Psychological response. In: Brånemark PI, Zarb GA, Albrektsson T (eds.): Tissue-Integrated Prosthesis. Osseointegration in Clinical Dentistry. Berlin, Quintessence Publishing Co., 1985:165-174.
16. Karlsson S, Carlsson GE: Oral motor function and phone in patients with implant-supported prostheses. In: Naert, Steenberghe v, Worthington P (eds.): Osseointegration in Oral Rehabilitation. London, Quintessence Books, 1993:123-131.
17. Grogono AL, Lancaster DM, Finger IM: Dental implants: a survey of patients' attitudes. J Prosthet Dent 1989; 62(5):573-6.
18. Harle TJ, Anderson JD: Patient Satisfaction with Implant-Supported Prostheses. Int J Prosthodont 1993;6:153-162.
19. Karlsson G: Halsoekonomisk analys av dentala implantat (thesis). Department of Health and Society, Linkoping University Sweden, 1991.
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Copyright The Journal of Dental Hygiene. Volume 74, Issue III, Summer 2000.
Reprinted with permission.
Patient Information
Life's simple pleasures can cause problems and pain for the millions of adults who suffer from permanent tooth loss.
Men and women of all ages are selfconscious about their dentures, bridges or missing teeth. Some have difficulty speaking because their dentures slip or click.
For others, the irritation and pain caused by dentures are constant reminders of the limitations they feel. Many are concerned about their appearance and may feel that their tooth loss has ``aged them" before their time.
Some regularly decline invitations to social events because they are unwilling to face the uncertainties of eating, speaking and laughing in public. Many can no longer enjoy their favorite foods, nor the social interaction with family and friends that accompanies special meals.
Now, more and more people are putting an end to these problems by choosing dental implants, a revolutionary way to replace missing teeth. Dental implants offer an excellent alternative to the limitations of conventional dentures, bridges and missing teeth.
Dental implants are changing the way people live. With them, people are rediscovering the comfort and confidence to eat, speak, laugh and enjoy life.
Why Are People Choosing Dental Implants?
A national survey of oral and maxillofacial surgeons found that patient interest and demand has grown significantly.
The survey found:
According to the survey, the reasons for the increased demand are:
Experts predict that the demand for the procedure will continue to grow as people become more familiar with the benefits of dental implants.
Dental implants are a great option for patients missing natural teeth, because they act as a secure anchor for artificial replacement teeth and eliminate the instability associated with surface adhesives and removable bridges.
Your natural teeth absorb biting pressure of up to 540 lbs. per square inch. Longtime denturewearers can often absorb no more than 50 lbs. per square inch. Dental implants, when properly placed, can withstand 450 lbs. per square inch of biting pressure.
Dental implants are made of materials that are compatible with human bone and tissue. The subperiosteal implants are surgically placed directly into the jawbone. Small posts are then attached to the implants which protrude through the gums. These posts provide stable anchors for artificial replacement teeth.
Based on patient needs, a single tooth, a partial bridge or a full set of replacement teeth are fitted to the implants and locked in place over the protruding posts. In appearance and in function, implants are the closest thing to natural teeth and a good alternative to conventional dentures.
Implants eliminate the daytoday frustrations and pain of illfitting dentures. They allow people to enjoy a healthy and varied diet without the restrictions many denture wearers face. With a sense of renewed selfconfidence, many people rediscover the excitement of an active lifestyle shared with family and friends and the chance to speak clearly and comfortably with coworkers.
For all these reasons, people with dental implants often say they feel better . . .
they look better . . . they live better.
partially edentulous
An oral and maxillofacial surgeon can determine if you are a candidate for dental implants. You will be evaluated based upon a number of things including dental health, lifestyle, jawbone quality and oral hygiene habits. In close consultation with your own dentist, the oral and maxillofacial surgeon can plan your dental implant treatment program.
Dental implant surgery is often done in an oral and maxillofacial surgeon's office. In some cases, the procedure is done in a hospital or ambulatory surgery center. In any event, an oral and maxillofacial surgeon can determine the most appropriate setting based on your individual needs.
A TwoPhase Procedure
For most patients, the placement of dental implants involves two surgical procedures. First, the implants are surgically placed into your jawbone. These small devices make up the framework needed to securely hold replacement teeth. For the first three to six months following surgery, the implants are beneath the surface of the gums, gradually bonding with the jawbone. During this time, you should be able to wear temporary dentures and eat a soft diet.
Some patients do report minor pain and swelling immediately after the procedure but most experience no change in their daily routines.
While the implants are bonding with the jawbone, new replacement teeth are fashioned by your dentist. The replacement teeth must clip onto the implants, fit securely in the mouth and withstand the daytoday movement and pressure created by chewing and speaking. So, it is important that they are created by a dentist with proper training in restorative techniques.
Once the implants have bonded to the jawbone, the second phase of the procedure begins. At this time, the oral and maxillofacial surgeon uncovers the implants and attaches small posts which will act as anchors for the artificial teeth. The posts protrude through the gumline but are not visible when artificial teeth are attached.
The entire process, from evaluation to completion, generally takes six to eight
months. During this time, most patients do not experience any disruption in their normal
business and social activities.
totally edentulous
Because dental implants are made of materials that are compatible with human bone, there is little chance for an allergic reaction in the body. However, implants can fail when proper oral hygiene techniques are not used. Dental implants require special individual care. Proper brushing, flossing, rinsing and regular checkups are critical to the longterm success of your implants.
Though dental implants are a relatively simple procedure, they generally warrant the expertise of two dental professionals_ an oral and maxillofacial surgeon and a restorative dentist.
Working as a team, the oral and maxillofacial surgeon and restorative dentist can determine if you are a candidate for implants and design an appropriate treatment plan. A restorative dentist, with training in dental implants, creates the replacement teeth. The doctor prepares the necessary molds and works with a dental laboratory to make sure that the denture or bridge will meet the particular needs of each patient. Additionally, dental implant patients should see a dentist for routine follow-up care and maintenance.
An oral and maxillofacial surgeon is a dental specialist who surgically treats the mouth and jaw area. Following dental school, an oral and maxillofacial surgeon completes several additional years of training in a hospital residency program and is trained to administer and monitor all types of anesthesia needed for oral and maxillofacial surgery procedures.
If you are among the millions of Americans who suffer from permanent tooth loss, you can eliminate the problems and pain caused by dentures, bridges or missing teeth. You can begin to rediscover the joy of eating healthy, speaking clearly and laughing comfortably.
Source: American Association of Oral and Maxillofacial Surgeons
9700 W. Bryn Mawr Avenue
Rosemont, IL 60018-5701
(847) 678-6200 Fax (847) 678-6286
www.aaoms.org
