Occlusal Practice in the Provision of Implant Borne Prostheses

Self-Study Examination

Instructions: After studying the text answer the following true/false or multiple choice questions.  Remember, there's only one answer to each question.

1. Unfavorable loading of the implant is the major cause of implant failure.

a) True
b) False

2. At present, the proprioceptive capability of restored implants is usually attributed to:

a) periodontal ligaments
b) bone deformation of the periosteal mechanoreceptors on implant loading
c) TMJ feedback
d) all of the above

3. It has been shown that the threshold of tactile sensitivity of loaded implants is approximately eight times less than that of natural teeth.

a) True
b) False

4. Implant occlusion is best adjusted using patient feedback during adjustments.

a) True
b) False

5. Implants are currently used in the following different types of prostheses:

a) fixed bridges
b) fixed crowns
c) precision removable dentures
d) removable overdentures (mucosa and implant supported)
e) all of the above

6. Implant success has been determined to be the absence of:

a) mobility
b) pain
c) infection or iatrogenic neuropathies
d) peri-implant vertical bone loss <1.0mm in the first year of loading <0.2mm per annum thereafter
e) all of the above

7. Perimucositis defers from peri-implantitis in that bone loss is associated with perimucositis.

a) TRUE
b) FALSE

8. The different stages of implant failure have been suggested to be (after Newman):

a) progressive bone loss
b) gingival hypertrophy
c) progressive deepening of pockets
d) progressive attachment loss
e) gingival inflammation

9. Suggested aetiological factors for implant failure are:

a) reduced host resistance
b) plaque accumulation
c) occlusal stress
d) systemic factors e.g., diabetes and smoking
e) a, b, c, d

10. The surgeon solely determines implant placement for the restorative dentist.

a) TRUE
b) FALSE

11. The radiographic appearance of saucerisation or furrowing may be a characteristic often associated with implant occlusal overload.

a) TRUE
b) FALSE

12. Causes of implant overload (occlusal stress) are numerous and include:

a) heavy occlusal contacts in centric occlusion
b) excess number of implants
c) working side interferences (as opposed to balanced contacts)
d) non-working side interferences
e) excessive buccal or lingual cantilever (the occlusal table too wide for the implant diameter)

13. Implants can be moved orthodontically.

a) TRUE
b) FALSE

14. An ideal occlusal scheme for implants includes posterior interferences, axial loading and group function.

a) TRUE
b) FALSE

15. The ideal occlusion for a single tooth implant includes:

a) passive centric relation contact with the remaining dentition.
b) occlusal forces loaded obliquely to the long axis of the implant
c) light load (infra-occlusion by 30µm) under heavy clenching
d) a and b

16. Implants will intrude underloading along with the natural dentition.

a) TRUE
b) FALSE

17. When fabricating a full-arch, implant supported prosthesis the simplest occlusal scheme to apply is the:

a) mutually protected occlusion (MPO)
b) lingualized occlusion (LO)

18. Use of cantilevered teeth with implants is empirically limited to a distal length of 10 - 20 mm. Recent suggestions recommend optimal cantilever length limited to 7 mm.

a) TRUE
b) FALSE

19. Maxillary overdentures require more implants than mandibular overdentures. The recommended number of implants to be used for a maxillary overdenture is:

a) 2 - 4
b) 4 - 6
c) 4 - 8
d) 8 - 10

20. Joining natural teeth with implants when fabricating a fixed prosthesis should be avoided.

a) TRUE
b) FALSE

21. The ideal crown length to implant length for a single crown is:

a) 1:2
b) 1:1
c) 1:3
d) 1:4

22. A ridge lap in implant prosthetics can be similarly compared to having the same unfavorable occlusal forces as those generated by a cantilever.

a) TRUE
b) FALSE

23. Lower implant success rates have been found in the posterior maxilla.

a) TRUE
b) FALSE