CDC Material Selection & Aesthetic Customization 5

Question 1

Which ceramic surface treatment increases the bond strength of feldspathic or glass-ceramic restorations to resin cement?

Accepted Answer

Etching with hydrofluoric acid followed by silane application

Answer

HF acid etching creates micromechanical retention on glass-ceramic surfaces, and silane coupling agent then provides a chemical bond to resin cement.

Question 2

In characterizing aged or worn anterior teeth, which surface texture technique on ceramic best replicates the flattened, worn incisal edge?

Accepted Answer

Flattening the incisal surface and reducing surface luster in that zone

Answer

Aged teeth exhibit worn, flat incisal edges with reduced gloss; replicating this in ceramic requires contouring and selective surface deglossing at the incisal.

Question 3

Which factor most commonly causes chipping of veneering ceramic from a zirconia framework in clinical service?

Accepted Answer

CTE mismatch between zirconia and veneering ceramic creating residual tensile stress

Answer

The CTE of zirconia (~10.5 ppm/°C) can differ from veneering porcelain, generating tensile residual stresses in the veneer layer upon cooling, leading to chipping.

Question 4

When shade-taking for an anterior ceramic restoration, at what time of day and for how long should the initial shade observation be made?

Accepted Answer

In natural light or balanced light for 5 seconds before eye fatigue sets in

Answer

Shade selection should occur in natural or balanced lighting for only a few seconds because color receptors fatigue rapidly, distorting perception.

Question 5

For a patient with a natural tooth shade of VITA A3.5, which ceramic modification most effectively increases the final restoration's value without changing hue?

Accepted Answer

Incorporating more opacifying agents or opal modifiers to lighten the ceramic body

Answer

Adding opacifying modifiers scatters more light within the ceramic body, raising the overall value (lightness) while keeping the hue constant.

(CDC) Certified Dental Ceramist Practice Test

(CDC) Certified Dental Ceramist Practice Test

CDC Material Selection & Aesthetic Customization 5