Crown & Bridge Fabrication Flashcards
7 cards from real CDT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Crown & Bridge Fabrication flashcards as text
What is the primary purpose of a proximal contact in a fixed bridge pontic design?
Answer: To prevent food impaction and maintain arch integrity
Proximal contacts in bridge pontics prevent food impaction and help maintain the spatial integrity of the dental arch.
Which alloy system is most susceptible to green corrosion (verdigris) when used in crown and bridge work?
Answer: Base-metal alloys containing copper
Base-metal alloys with high copper content are prone to green corrosion (verdigris) due to copper oxide formation in oral environments.
When waxing a full-contour crown, the ideal buccolingual width of the occlusal table on a mandibular molar should be approximately what fraction of the total tooth width?
Answer: One-third
The occlusal table should be approximately one-third of the total buccolingual width to reduce lateral forces and preserve periodontium.
During the soldering of a fixed partial denture, which flux type is appropriate for high-fusing base-metal alloys?
Answer: Fluoride-containing flux
Fluoride-containing fluxes are required for base-metal alloys because they effectively dissolve the tenacious chromium oxide layer that forms on these alloys.
A 'working cast' in crown and bridge fabrication differs from a 'master cast' primarily because the working cast:
Answer: Has removable dies that can be separated from the cast
A working cast features individually removable dies so each preparation can be accessed independently while maintaining the full-arch relationship.
Which die spacer application technique best ensures an adequate cement space without compromising marginal fit?
Answer: Apply spacer stopping 0.5–1 mm short of the finish line
Die spacer should stop 0.5–1 mm short of the finish line to create cement relief while allowing the crown margin to seat accurately at the preparation margin.
When evaluating a metal coping for porcelain-fused-to-metal (PFM) crown, what minimum metal thickness is generally recommended to prevent flexure and porcelain fracture?
Answer: 0.3–0.5 mm
A minimum coping thickness of 0.3–0.5 mm is recommended to provide adequate rigidity and prevent flexure that could crack the overlying porcelain.