INBDE Prosthodontics and Occlusion 2 — Questions and Answers
Question 1: Which of the following is a contraindication to implant placement?
- Controlled type 2 diabetes (HbA1c <7%)
- History of radiation to the head and neck (Correct answer)
- Age over 60
- Single tooth replacement in posterior region
Correct answer: History of radiation to the head and neck
Prior radiation therapy to the head and neck significantly compromises bone vascularity and healing, increasing the risk of osteoradionecrosis and implant failure.
Question 2: The neutral zone in complete denture construction represents:
- The space between the residual ridges
- The area where buccal and lingual muscle forces are in equilibrium (Correct answer)
- The occlusal plane height
- The area of maximum bone support
Correct answer: The area where buccal and lingual muscle forces are in equilibrium
The neutral zone is the area in the edentulous mouth where the outward tongue pressure equals the inward cheek and lip pressure, providing the ideal location for artificial teeth.
Question 3: Osseointegration of a dental implant refers to:
- Fibrous connective tissue encapsulation of the implant
- Direct structural and functional connection between bone and the implant surface (Correct answer)
- The process of implant insertion surgery
- Soft tissue healing around the abutment
Correct answer: Direct structural and functional connection between bone and the implant surface
Osseointegration is the direct bone-to-implant contact without an intervening fibrous layer, providing the rigid anchorage that dental implants depend upon.
Question 4: The Christensen phenomenon describes:
- The development of a posterior open bite in protrusive movement with balanced occlusion dentures (Correct answer)
- Condylar guidance angle's effect on cusp height
- Bennett movement of the condyle
- Disclusion of posterior teeth in lateral excursion
Correct answer: The development of a posterior open bite in protrusive movement with balanced occlusion dentures
The Christensen phenomenon is the opening of a wedge-shaped space posteriorly during protrusive movement in complete dentures without balanced occlusion.
Question 5: Fixed partial denture (bridge) pontic designs should ideally contact the residual ridge:
- With maximum pressure to prevent food impaction
- With light contact that can be cleansed (modified ridge lap or ovate) (Correct answer)
- Without any contact (sanitary/hygienic pontic)
- In a broad flat contact (full ridge lap)
Correct answer: With light contact that can be cleansed (modified ridge lap or ovate)
The modified ridge lap and ovate pontic designs provide acceptable aesthetics with light tissue contact that can be cleaned, balancing appearance and hygiene.
Question 6: Protrusive records in complete denture fabrication are used to set the:
- Condylar guidance angle on the articulator (Correct answer)
- Occlusal vertical dimension
- Horizontal overlap of anterior teeth
- Centric relation position
Correct answer: Condylar guidance angle on the articulator
Protrusive records allow the clinician to program the condylar guidance angle (Hanau's formula: H = P/8 + 12) on the semi-adjustable articulator.
INBDE Prosthodontics and Occlusion 2
Which of the following is a contraindication to implant placement?