CDT CDT Complete Denture Fabrication 2 — Questions and Answers
Question 1: What is the 'try-in' appointment in complete denture fabrication designed to verify?
- The final polish and finish of the acrylic base
- Tooth arrangement, occlusion, esthetics, and phonetics before final processing (Correct answer)
- The accuracy of the master cast
- The strength of the acrylic after processing
Correct answer: Tooth arrangement, occlusion, esthetics, and phonetics before final processing
The wax try-in allows assessment and correction of tooth position, occlusal scheme, vertical dimension, and esthetics before irreversible acrylic processing.
Question 2: What is 'processing shrinkage' in acrylic denture fabrication, and how is it managed?
- Dimensional expansion of acrylic during curing; managed by using a slower heat cure
- Dimensional contraction of acrylic during polymerization; managed by using proper packing and curing cycles (Correct answer)
- Porosity in the acrylic base; managed by adding monomer
- Discoloration of acrylic over time; managed by polishing
Correct answer: Dimensional contraction of acrylic during polymerization; managed by using proper packing and curing cycles
Acrylic resin shrinks approximately 0.2–0.5% during polymerization, and proper flask packing technique and controlled curing cycles minimize distortion.
Question 3: What is the purpose of 'festooning' the denture wax prior to processing?
- To add extra wax for strength
- To carve the wax to simulate natural gingival contours and root prominences (Correct answer)
- To create retention for the artificial teeth
- To mark the midline and lip support area
Correct answer: To carve the wax to simulate natural gingival contours and root prominences
Festooning shapes the wax base to mimic natural gingival architecture, including root eminences and interdental papillae, for a lifelike esthetic result.
Question 4: Which acrylic resin polymerization method produces the least porosity in a complete denture base?
- Autopolymerizing (cold-cure) acrylic at room temperature
- Heat-cured acrylic processed in a water bath at a controlled long-cure cycle (Correct answer)
- Microwave-cured acrylic
- Light-cured urethane dimethacrylate
Correct answer: Heat-cured acrylic processed in a water bath at a controlled long-cure cycle
A long, controlled water-bath heat cure (e.g., 74°C for 8 hours or 74°C/2hr + 100°C/1hr) minimizes residual monomer and gaseous porosity.
Question 5: What is the 'neutral zone' concept in complete denture construction?
- The area of the palate with no tissue contact
- The space where forces from the tongue and cheeks/lips balance, used to position denture teeth (Correct answer)
- The midline of the denture
- The post-dam area at the posterior of the upper denture
Correct answer: The space where forces from the tongue and cheeks/lips balance, used to position denture teeth
The neutral zone is where musculature forces from the tongue and perioral muscles balance, providing the most stable position for denture teeth.
Question 6: What type of occlusal scheme is most commonly recommended for complete denture patients to maximize stability?
- Group function occlusion
- Lingualized occlusion or balanced occlusion (Correct answer)
- Canine-guided occlusion
- Edge-to-edge occlusion
Correct answer: Lingualized occlusion or balanced occlusion
Balanced occlusion (bilateral simultaneous contact in all excursions) or lingualized occlusion is preferred for complete dentures to prevent tipping and maximize stability.
CDT CDT Complete Denture Fabrication 2
What is the 'try-in' appointment in complete denture fabrication designed to verify?