DENTAL MATERIALS EXAM 4 | DENTAL
HYGIENIST| DENTAL HYGIENIST | LATEST
2025-2026 QUESTION AND CORRECT ANSWER
WITH EXPLANATION WEST COAST
UNIVERSITY
1. Question
A patient presents with multiple composite failures across different
quadrants within 1 year. What is the MOST likely underlying systemic
issue?
A. Excess fluoride exposure
B. High caries risk and poor biofilm control
C. Overuse of polishing instruments
D. Increased enamel mineralization
Correct Answer: B
Rationale: Widespread failure usually indicates uncontrolled plaque and
caries activity.
2. Question
Which adhesive step is MOST vulnerable to contamination failure?
A. Enamel etching
B. Dentin bonding resin infiltration
C. Light curing
D. Finishing and polishing
Correct Answer: B
Rationale: Dentin bonding is highly sensitive to moisture and
contamination.
3. Question
What is the PRIMARY function of the hybrid layer?
,A. Increase color stability
B. Create micromechanical interlocking between resin and collagen
C. Reduce plaque formation
D. Increase fluoride release
Correct Answer: B
Rationale: The hybrid layer is essential for durable bonding.
4. Question
A composite restoration debonds after a few weeks. What is the MOST
likely cause?
A. Excess fluoride
B. Polymerization shrinkage stress exceeding bond strength
C. High salivary pH
D. Increased enamel density
Correct Answer: B
Rationale: Shrinkage stress disrupts adhesive interfaces.
5. Question
Which material property is MOST important for resisting chewing forces?
A. Color stability
B. Compressive strength
C. Taste
D. Solubility
Correct Answer: B
Rationale: Compressive strength determines load resistance.
6. Question
What is the MAIN disadvantage of composite resin in posterior
restorations?
, A. High strength
B. Polymerization shrinkage
C. High radiopacity
D. Good esthetics
Correct Answer: B
Rationale: Shrinkage leads to marginal gaps and failure.
7. Question
Which material is MOST susceptible to galvanic corrosion?
A. Ceramic
B. Dissimilar metallic restorations
C. Composite resin
D. Acrylic resin
Correct Answer: B
Rationale: Different metals in saliva create electrochemical reactions.
8. Question
What is the PRIMARY role of bonding primer?
A. Increase hardness
B. Improve resin infiltration into dentin
C. Remove decay
D. Increase fluoride release
Correct Answer: B
Rationale: Primers enhance wetting and penetration.
9. Question
Which failure mode is MOST common in ceramics?
A. Plastic deformation
B. Crack propagation under tensile stress
HYGIENIST| DENTAL HYGIENIST | LATEST
2025-2026 QUESTION AND CORRECT ANSWER
WITH EXPLANATION WEST COAST
UNIVERSITY
1. Question
A patient presents with multiple composite failures across different
quadrants within 1 year. What is the MOST likely underlying systemic
issue?
A. Excess fluoride exposure
B. High caries risk and poor biofilm control
C. Overuse of polishing instruments
D. Increased enamel mineralization
Correct Answer: B
Rationale: Widespread failure usually indicates uncontrolled plaque and
caries activity.
2. Question
Which adhesive step is MOST vulnerable to contamination failure?
A. Enamel etching
B. Dentin bonding resin infiltration
C. Light curing
D. Finishing and polishing
Correct Answer: B
Rationale: Dentin bonding is highly sensitive to moisture and
contamination.
3. Question
What is the PRIMARY function of the hybrid layer?
,A. Increase color stability
B. Create micromechanical interlocking between resin and collagen
C. Reduce plaque formation
D. Increase fluoride release
Correct Answer: B
Rationale: The hybrid layer is essential for durable bonding.
4. Question
A composite restoration debonds after a few weeks. What is the MOST
likely cause?
A. Excess fluoride
B. Polymerization shrinkage stress exceeding bond strength
C. High salivary pH
D. Increased enamel density
Correct Answer: B
Rationale: Shrinkage stress disrupts adhesive interfaces.
5. Question
Which material property is MOST important for resisting chewing forces?
A. Color stability
B. Compressive strength
C. Taste
D. Solubility
Correct Answer: B
Rationale: Compressive strength determines load resistance.
6. Question
What is the MAIN disadvantage of composite resin in posterior
restorations?
, A. High strength
B. Polymerization shrinkage
C. High radiopacity
D. Good esthetics
Correct Answer: B
Rationale: Shrinkage leads to marginal gaps and failure.
7. Question
Which material is MOST susceptible to galvanic corrosion?
A. Ceramic
B. Dissimilar metallic restorations
C. Composite resin
D. Acrylic resin
Correct Answer: B
Rationale: Different metals in saliva create electrochemical reactions.
8. Question
What is the PRIMARY role of bonding primer?
A. Increase hardness
B. Improve resin infiltration into dentin
C. Remove decay
D. Increase fluoride release
Correct Answer: B
Rationale: Primers enhance wetting and penetration.
9. Question
Which failure mode is MOST common in ceramics?
A. Plastic deformation
B. Crack propagation under tensile stress
