DDS Prosthodontics and Restorative Dentistry 3

Question 1

The caries-detecting dye used during cavity preparation stains which tissue?

Accepted Answer

Denatured (infected, non-vital) dentin collagen that cannot remineralize

Answer

All demineralized enamel and dentin

Answer

All dentin exposed during preparation

Answer

Bacteria within dentinal tubules only

Question 2

Which cement provides the best seal against microleakage when used as a base under amalgam restorations?

Accepted Answer

Glass ionomer cement

Answer

Zinc phosphate cement

Answer

Calcium hydroxide

Answer

Zinc oxide eugenol cement

Question 3

The Ante's Law in fixed partial denture design states that:

Accepted Answer

The combined root surface area of abutment teeth must equal or exceed that of the teeth being replaced

Answer

The pontic span should not exceed the length of the abutment teeth

Answer

Each bridge unit requires 1 mm occlusal reduction for porcelain

Answer

Abutment teeth must have a crown-to-root ratio of at least 1:1.5

Question 4

Which type of impression material is dimensionally most stable over time and most accurate for implant-level impressions?

Accepted Answer

Polyether

Answer

Alginate (irreversible hydrocolloid)

Answer

Polysulfide

Answer

Zinc oxide eugenol impression paste

Question 5

In Class V composite resin restorations, which factor most contributes to marginal failure at the gingival margin?

Accepted Answer

Poor bonding to cementum/dentin and flexural stress from toothbrushing (abfraction)

Answer

Insufficient light curing through intact enamel

Answer

Excessive fluoride incorporation weakening the adhesive interface

Answer

Thermal expansion mismatch between composite and enamel

Question 6

When taking a full-arch alginate impression, saliva contamination most commonly causes which problem?

Accepted Answer

Surface porosity and voids in the impression due to hydrophilicity disruption

Answer

Premature alginate gelation

Answer

Excessive detail in the soft tissue areas

Answer

Permanent distortion of the tray material