CDC Clinical Procedures & Protocols 2 — Questions and Answers
Question 1: When communicating shade information to a dental laboratory, which method provides the most accurate and reproducible color documentation?
- Verbal description over phone
- Written shade tab notation alone
- Digital shade matching with spectrophotometer readings (Correct answer)
- Patient self-reported preference
Correct answer: Digital shade matching with spectrophotometer readings
Spectrophotometers provide objective, reproducible numerical color data that eliminates subjective interpretation errors inherent in verbal or visual shade communication.
Question 2: During the try-in phase of a porcelain restoration, the ceramist notices a slight color mismatch under dental operatory lighting. What is the most appropriate next step?
- Deliver the restoration immediately as lighting varies
- Evaluate the restoration under multiple light sources before making adjustments (Correct answer)
- Add surface stain without additional evaluation
- Return the case to the lab without documentation
Correct answer: Evaluate the restoration under multiple light sources before making adjustments
Evaluating color under multiple light sources (metamerism check) ensures the restoration matches in all clinical lighting conditions before any irreversible corrections.
Question 3: What is the primary purpose of using a die spacer in fixed prosthodontic procedures?
- To enhance aesthetics of the final restoration
- To create space for the luting cement film thickness (Correct answer)
- To increase the strength of the porcelain
- To prevent porcelain cracking during firing
Correct answer: To create space for the luting cement film thickness
Die spacer creates controlled space between the restoration and the prepared tooth to accommodate the cement luting film, ensuring proper seating and marginal fit.
Question 4: A ceramist receives a case with a preparation margin that transitions from supragingival anteriorly to subgingival posteriorly. How should this affect fabrication protocol?
- Treat all margins identically regardless of location
- Request a remade impression as mixed margins are unacceptable
- Adjust wax-up and ceramic layering to address varying visibility zones (Correct answer)
- Only focus on the supragingival portion for aesthetics
Correct answer: Adjust wax-up and ceramic layering to address varying visibility zones
Mixed margin locations require zone-specific ceramic planning — visible supragingival areas demand higher aesthetic detail while subgingival zones prioritize marginal seal.
Question 5: Which occlusal contact pattern is most desirable for posterior all-ceramic restorations in centric occlusion?
- Single point contact with steep cuspal inclines
- Broad flat contact across the entire occlusal surface
- Multiple tripod contacts distributing forces evenly (Correct answer)
- No occlusal contact to protect the ceramic
Correct answer: Multiple tripod contacts distributing forces evenly
Tripod contacts distribute occlusal forces across multiple stable points, reducing stress concentration that could fracture all-ceramic restorations.
Question 6: When fabricating a ceramic restoration for a patient with bruxism, which material modification is most appropriate?
- Use the thinnest possible ceramic for flexibility
- Increase ceramic thickness and consider zirconia-based materials (Correct answer)
- Use high-leucite porcelain for maximum translucency
- Apply extra surface glaze to increase hardness
Correct answer: Increase ceramic thickness and consider zirconia-based materials
Bruxism generates excessive occlusal forces requiring increased ceramic thickness and high-strength substrates like zirconia to resist fracture.
Question 7: What is the standard protocol for verifying the internal fit of a ceramic crown before final cementation?
- Visual inspection of the external margins only
- Use of fit-checking spray or silicone disclosing medium on internal surface (Correct answer)
- Patient's subjective report of comfort
- Radiographic assessment alone
Correct answer: Use of fit-checking spray or silicone disclosing medium on internal surface
Fit-checking spray or silicone disclosing medium applied to the internal crown surface reveals high spots and contact areas that need adjustment for optimal seating.
CDC Clinical Procedures & Protocols 2
When communicating shade information to a dental laboratory, which method provides the most accurate and reproducible color documentation?