ORE Part 2 Prosthetics & Dentures 4 — Questions and Answers
Question 1: What are the two main types of implant-retained complete overdentures based on their attachment systems?
- Ball/locator attachments (stud type) and bar-and-clip attachments (Correct answer)
- Screw-retained and cement-retained
- Metal and acrylic
- Fixed and removable bridge types
Correct answer: Ball/locator attachments (stud type) and bar-and-clip attachments
Implant overdentures are primarily retained by either ball/locator stud attachments (individual implant retention) or bar-and-clip systems (connecting implants for greater stability).
Question 2: What is the purpose of a registration rim (occlusal rim) at the jaw registration stage of complete denture construction?
- Record jaw relationships (OVD, occlusal plane, centre line) and tooth positions for the lab (Correct answer)
- Take the final impression
- Test tooth arrangements before processing
- Record shade only
Correct answer: Record jaw relationships (OVD, occlusal plane, centre line) and tooth positions for the lab
Registration rims allow the clinician to record the correct OVD, establish the occlusal plane and lip support, mark the centre line and canine positions, and transfer these to the articulator for tooth arrangement.
Question 3: What is a common cause of persistent gagging with a complete upper denture?
- Over-extension of the posterior palatal border (Correct answer)
- Under-extension of the denture
- Incorrect shade of teeth
- Too much freeway space
Correct answer: Over-extension of the posterior palatal border
Over-extension of the posterior border into the soft palate stimulates the gag reflex; trimming the posterior border to the vibrating line (Ah line) resolves this in many cases.
Question 4: When should a definitive reline of a complete denture be performed?
- After ridge remodelling is stable (6–12 months after tooth loss) (Correct answer)
- At the immediate denture fit appointment
- At 3 months regardless of tissue stability
- Never — replace with new denture instead
Correct answer: After ridge remodelling is stable (6–12 months after tooth loss)
Definitive relining should be deferred until alveolar ridge remodelling has stabilised, typically 6–12 months after extractions, to ensure the reline captures a stable tissue record.
Question 5: Which articulator type is required for the most accurate transfer of patient jaw relationships in complex prosthodontics?
- Fully adjustable (Denar, Whip Mix) with face-bow record (Correct answer)
- Average value articulator
- Simple hinge articulator
- Non-adjustable articulator
Correct answer: Fully adjustable (Denar, Whip Mix) with face-bow record
Fully adjustable articulators with a face-bow transfer accurately replicate the patient's condylar angles and hinge axis, essential for complex restorative and complete denture cases.
Question 6: What is the difference between a balanced articulation and a group function occlusal scheme?
- Balanced articulation maintains contacts bilaterally in all excursions; group function is unilateral working-side contacts only (Correct answer)
- They are identical
- Group function is used for complete dentures; balanced for natural teeth only
- Balanced articulation only applies to natural dentition
Correct answer: Balanced articulation maintains contacts bilaterally in all excursions; group function is unilateral working-side contacts only
Balanced articulation maintains bilateral tooth contacts throughout all excursive movements, used for complete dentures; group function relies on multiple unilateral working-side contacts, used for natural dentition or RPDs.
ORE Part 2 Prosthetics & Dentures 4
What are the two main types of implant-retained complete overdentures based on their attachment systems?