CDC Ceramic Firing & Kiln Operations Flashcards
6 cards from real CDC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CDC Ceramic Firing & Kiln Operations flashcards as text
Regular kiln calibration is important in a dental laboratory because:
Answer: Thermocouples age and drift, causing actual temperatures to differ from displayed values
Thermocouple degradation over time causes a discrepancy between the displayed and actual firing temperature, leading to inconsistent results.
What is the purpose of applying a 'separator' (releasing agent) to firing pins and trays before placing ceramic restorations?
Answer: To prevent the ceramic from bonding to the tray or pin during high-temperature firing
Separating agents prevent the softened ceramic from adhering to firing supports, which would cause fractures or distortion when removing the restoration.
During porcelain layering, 'bisque bake' firing is performed to:
Answer: Partially sinter the porcelain for evaluation and adjustment before final firing
A bisque bake partially sinters the porcelain to a solid but unglazed state, allowing the ceramist to evaluate contour and shade before final adjustments.
Which of the following kiln malfunctions would most likely result in consistently under-fired porcelain restorations?
Answer: Heating element failure causing a drop in maximum temperature
A failing heating element cannot reach the programmed peak temperature, resulting in under-sintered, porous, and weak ceramic restorations.
When firing multiple restorations in the same kiln cycle, they should be:
Answer: Spaced apart to allow uniform heat circulation around each piece
Adequate spacing between restorations ensures even heat distribution and prevents thermal shadowing that could cause uneven sintering.
After firing, a PFM (porcelain-fused-to-metal) crown exhibits porcelain that has pulled away from the metal at the margin. This defect is most likely caused by:
Answer: Inadequate surface preparation or contamination of the metal framework
Poor metal preparation or contamination (e.g., oil, saliva) prevents proper chemical bonding between the opaque porcelain and the metal substrate, causing delamination.