CDT Removable Prosthodontics 2 — Questions and Answers
Question 1: Which type of denture base material is most commonly used in complete denture fabrication due to its ease of processing and patient acceptance?
- Acrylic resin (PMMA) (Correct answer)
- Vulcanized rubber
- Nylon thermoplastic
- Cast metal alloy
Correct answer: Acrylic resin (PMMA)
Polymethyl methacrylate (PMMA) acrylic resin is the standard denture base material because it is easy to process, repair, and aesthetically acceptable.
Question 2: The post dam (posterior palatal seal) in a maxillary complete denture is designed to:
- Increase vertical dimension of occlusion
- Create a peripheral seal to aid retention (Correct answer)
- Support the posterior teeth
- Prevent fracture of the denture base
Correct answer: Create a peripheral seal to aid retention
The posterior palatal seal creates a peripheral seal at the vibrating line, preventing air from breaking the suction that aids denture retention.
Question 3: When surveying a cast for a removable partial denture, the surveying rod is typically positioned parallel to:
- The occlusal plane
- The path of insertion and removal (Correct answer)
- The labial surface of anterior teeth
- The retromolar pad
Correct answer: The path of insertion and removal
The surveyor analyzes undercuts relative to the proposed path of insertion so the RPD can seat and be removed without binding.
Question 4: A stress-breaker in a removable partial denture framework is used to:
- Increase the rigidity of the major connector
- Reduce forces transmitted to abutment teeth (Correct answer)
- Improve esthetics of the prosthesis
- Provide additional indirect retention
Correct answer: Reduce forces transmitted to abutment teeth
Stress-breakers (stress relievers) introduce a flexible joint that reduces harmful torquing forces transferred to abutment teeth during function.
Question 5: Which occlusal scheme is generally recommended for complete dentures worn by patients with well-resorbed ridges?
- Cusped anatomical occlusion
- Lingualized occlusion
- Non-anatomic (monoplane) occlusion (Correct answer)
- Cross-bite occlusion
Correct answer: Non-anatomic (monoplane) occlusion
Non-anatomic or monoplane occlusion reduces horizontal forces on resorbed ridges, providing greater stability during function.
Question 6: The purpose of blockout wax applied to a master cast before duplication is to:
- Improve the surface texture of the refractory cast
- Eliminate undercuts that would prevent RPD framework removal (Correct answer)
- Increase the vertical dimension on the cast
- Simulate the patient's soft tissue color
Correct answer: Eliminate undercuts that would prevent RPD framework removal
Blockout wax fills undesirable undercut areas on the cast so the cast can be duplicated and the framework can be withdrawn from the investment.
Question 7: Centric relation in edentulous patients is recorded to:
- Determine the shade of artificial teeth
- Establish a repeatable jaw relationship for mounting casts (Correct answer)
- Measure the width of the residual ridge
- Select the denture base color
Correct answer: Establish a repeatable jaw relationship for mounting casts
Centric relation provides a reproducible mandibular position from which vertical dimension and occlusion can be accurately established on an articulator.
CDT Removable Prosthodontics 2
Which type of denture base material is most commonly used in complete denture fabrication due to its ease of processing and patient acceptance?