CDC Material Selection & Aesthetic Customization 2 — Questions and Answers
Question 1: Which ceramic system is most appropriate for fabricating a high-strength posterior crown that also requires translucency matching natural dentition?
- Feldspathic porcelain
- Zirconia-reinforced lithium silicate (ZLS) (Correct answer)
- Leucite-reinforced glass ceramic
- Acrylic resin
Correct answer: Zirconia-reinforced lithium silicate (ZLS)
Zirconia-reinforced lithium silicate combines high flexural strength with acceptable translucency, making it suitable for posterior crowns requiring aesthetics.
Question 2: When customizing the chroma of a ceramic restoration, increasing chroma primarily affects which optical characteristic?
- Lightness of the tooth
- Saturation of the hue (Correct answer)
- Dominant wavelength of color
- Surface gloss level
Correct answer: Saturation of the hue
Chroma refers to the saturation or intensity of a hue; increasing chroma makes the color appear more vivid and saturated.
Question 3: A patient presents with hypocalcified white spot lesions on adjacent teeth. Which layering technique best mimics this internal characterization?
- Surface staining with opaque white modifier
- Incorporating opacious dentin internally before adding enamel layer (Correct answer)
- Applying opalescent glaze over full contour zirconia
- Using high-translucency ingots without internal build-up
Correct answer: Incorporating opacious dentin internally before adding enamel layer
Opacious dentin layered internally replicates the subsurface opacity of hypocalcification spots, creating depth and realism.
Question 4: Which factor most significantly influences the selection between press-ceramic and CAD/CAM-milled ceramic for an anterior veneer?
- Patient age and systemic health
- Required surface texture and marginal fit precision (Correct answer)
- Shade of adjacent teeth
- Type of provisional restoration used
Correct answer: Required surface texture and marginal fit precision
CAD/CAM milling offers superior marginal accuracy while press ceramics allow precise control of surface texture and optical characterization during wax-up.
Question 5: Fluorescence in natural teeth originates primarily from which structure?
- Enamel rods
- Dentin collagen and organic matrix (Correct answer)
- Cementum layer
- Pulp tissue
Correct answer: Dentin collagen and organic matrix
Dentin's organic collagen matrix fluoresces under UV light, giving natural teeth their characteristic blue-white glow in black-light conditions.
Question 6: When selecting ceramic for a patient with severe bruxism requiring a mandibular posterior bridge, which material property is most critical?
- High translucency
- High flexural strength exceeding 800 MPa (Correct answer)
- Coefficient of thermal expansion matching metal
- Low hardness to reduce antagonist wear
Correct answer: High flexural strength exceeding 800 MPa
High flexural strength (>800 MPa, typical of high-strength zirconia) resists fracture under heavy occlusal loading in bruxism patients.
Question 7: In the Munsell color system, which parameter directly corresponds to the brightness or darkness of a tooth shade?
- Hue
- Chroma
- Value (Correct answer)
- Saturation
Correct answer: Value
Value in the Munsell system describes the lightness or darkness of a color, ranging from black (0) to white (10).
CDC Material Selection & Aesthetic Customization 2
Which ceramic system is most appropriate for fabricating a high-strength posterior crown that also requires translucency matching natural dentition?