___________________________________________________________________
INBDE Restorative Dentistry Practice
Exam 2026 | 100 Advanced Questions &
Answers with Detailed Rationales |
Integrated National Board Dental
Examination Prep & Study Guide
1. A patient presents with a deep carious lesion on a vital mandibular first
molar. After caries removal, a thin layer of affected dentin remains over the
pulp, with no pulpal exposure and no spontaneous pain. Which
management is most appropriate?
A. Complete removal of all affected dentin until hard dentin is reached
B. Selective caries removal with a protective liner/seal and definitive restoration
C. Immediate pulpectomy
D. Extraction
Answer: Selective caries removal with a protective liner/seal and definitive
restoration
Rationale: Selective caries removal in a deep lesion minimizes the risk of pulp
exposure while sealing residual affected dentin from the oral environment. In a
,tooth with normal pulp or reversible pulpal symptoms, preservation of pulpal
vitality is preferred.
2. A Class II composite restoration repeatedly develops marginal staining at
the gingival margin despite appropriate bonding technique. Which factor is
most likely contributing to the problem?
A. Excessive occlusal anatomy
B. Polymerization shrinkage and inadequate gingival adaptation
C. Excessive fluoride exposure
D. Excessive enamel etching
Answer: Polymerization shrinkage and inadequate gingival adaptation
Rationale: Composite polymerization shrinkage can generate interfacial stress,
particularly at gingival margins where enamel is limited or absent. Proper
isolation, incremental placement, matrix adaptation, and controlled curing
reduce marginal defects.
3. A patient requires a posterior restoration in an area with a high caries risk
and limited ability to maintain ideal moisture control. Which material is
generally most advantageous when fluoride release and moisture tolerance
are priorities?
A. Conventional composite resin
B. Amalgam
C. Glass ionomer cement
D. Unfilled resin
Answer: Glass ionomer cement
Rationale: Glass ionomer cement chemically bonds to tooth structure, releases
fluoride, and is more tolerant of moisture than resin-based materials. Its
mechanical properties, however, limit its use in high-stress posterior areas
unless an appropriate reinforced formulation is selected.
, 4. A mandibular molar has extensive coronal destruction but adequate
remaining tooth structure circumferentially. Which principle is most
important when planning a definitive crown?
A. Eliminate all axial wall height
B. Preserve sound tooth structure while providing adequate resistance and
retention form
C. Maximize taper of the preparation
D. Extend the preparation subgingivally whenever possible
Answer: Preserve sound tooth structure while providing adequate resistance
and retention form
Rationale: Fixed prosthodontic preparation requires a balance between
conservation and mechanical requirements. Excessive taper or unnecessary
tooth reduction compromises retention, resistance, and structural integrity.
5. A patient has a large posterior composite restoration with a cusp that is
thin and undermined. Which approach is most appropriate?
A. Leave the cusp unsupported
B. Reduce and cover the weakened cusp as part of the restoration when indicated
C. Remove the entire tooth
D. Place only a sealant
Answer: Reduce and cover the weakened cusp as part of the restoration when
indicated
Rationale: Thin, undermined cusps are susceptible to fracture under occlusal
loading. Cuspal coverage can redistribute stresses and protect remaining tooth
structure when the extent of structural loss warrants it.
6. During placement of a posterior composite, the clinician notices
contamination of the etched enamel with saliva before bonding. What
should be done?
, A. Continue bonding without modification
B. Apply additional composite immediately
C. Re-etch and repeat the bonding procedure according to the adhesive system
D. Place amalgam over the contaminated surface
Answer: Re-etch and repeat the bonding procedure according to the adhesive
system
Rationale: Salivary contamination can compromise the quality of the etched
substrate and adhesive interface. Reconditioning the surface according to the
manufacturer's adhesive protocol is preferable to bonding over a contaminated
surface.
7. Which property of resin composite is most directly responsible for the need
for incremental placement in deep posterior restorations?
A. Fluoride release
B. Chemical adhesion to dentin
C. Polymerization shrinkage and limitations of depth of cure
D. High radiopacity
Answer: Polymerization shrinkage and limitations of depth of cure
Rationale: Incremental placement can improve light penetration and curing
while reducing the effective volume of composite polymerized at one time,
thereby helping manage polymerization shrinkage stress.
8. A tooth has a deep carious lesion and symptoms consistent with reversible
pulpitis. After selective caries removal, the cavity is restored with a well-
sealed adhesive restoration. Why is an effective coronal seal particularly
important?
A. It increases enamel thickness
B. It prevents all future caries
C. It limits bacterial nutrient supply and further contamination of the dentin-pulp
complex
D. It eliminates occlusal forces
INBDE Restorative Dentistry Practice
Exam 2026 | 100 Advanced Questions &
Answers with Detailed Rationales |
Integrated National Board Dental
Examination Prep & Study Guide
1. A patient presents with a deep carious lesion on a vital mandibular first
molar. After caries removal, a thin layer of affected dentin remains over the
pulp, with no pulpal exposure and no spontaneous pain. Which
management is most appropriate?
A. Complete removal of all affected dentin until hard dentin is reached
B. Selective caries removal with a protective liner/seal and definitive restoration
C. Immediate pulpectomy
D. Extraction
Answer: Selective caries removal with a protective liner/seal and definitive
restoration
Rationale: Selective caries removal in a deep lesion minimizes the risk of pulp
exposure while sealing residual affected dentin from the oral environment. In a
,tooth with normal pulp or reversible pulpal symptoms, preservation of pulpal
vitality is preferred.
2. A Class II composite restoration repeatedly develops marginal staining at
the gingival margin despite appropriate bonding technique. Which factor is
most likely contributing to the problem?
A. Excessive occlusal anatomy
B. Polymerization shrinkage and inadequate gingival adaptation
C. Excessive fluoride exposure
D. Excessive enamel etching
Answer: Polymerization shrinkage and inadequate gingival adaptation
Rationale: Composite polymerization shrinkage can generate interfacial stress,
particularly at gingival margins where enamel is limited or absent. Proper
isolation, incremental placement, matrix adaptation, and controlled curing
reduce marginal defects.
3. A patient requires a posterior restoration in an area with a high caries risk
and limited ability to maintain ideal moisture control. Which material is
generally most advantageous when fluoride release and moisture tolerance
are priorities?
A. Conventional composite resin
B. Amalgam
C. Glass ionomer cement
D. Unfilled resin
Answer: Glass ionomer cement
Rationale: Glass ionomer cement chemically bonds to tooth structure, releases
fluoride, and is more tolerant of moisture than resin-based materials. Its
mechanical properties, however, limit its use in high-stress posterior areas
unless an appropriate reinforced formulation is selected.
, 4. A mandibular molar has extensive coronal destruction but adequate
remaining tooth structure circumferentially. Which principle is most
important when planning a definitive crown?
A. Eliminate all axial wall height
B. Preserve sound tooth structure while providing adequate resistance and
retention form
C. Maximize taper of the preparation
D. Extend the preparation subgingivally whenever possible
Answer: Preserve sound tooth structure while providing adequate resistance
and retention form
Rationale: Fixed prosthodontic preparation requires a balance between
conservation and mechanical requirements. Excessive taper or unnecessary
tooth reduction compromises retention, resistance, and structural integrity.
5. A patient has a large posterior composite restoration with a cusp that is
thin and undermined. Which approach is most appropriate?
A. Leave the cusp unsupported
B. Reduce and cover the weakened cusp as part of the restoration when indicated
C. Remove the entire tooth
D. Place only a sealant
Answer: Reduce and cover the weakened cusp as part of the restoration when
indicated
Rationale: Thin, undermined cusps are susceptible to fracture under occlusal
loading. Cuspal coverage can redistribute stresses and protect remaining tooth
structure when the extent of structural loss warrants it.
6. During placement of a posterior composite, the clinician notices
contamination of the etched enamel with saliva before bonding. What
should be done?
, A. Continue bonding without modification
B. Apply additional composite immediately
C. Re-etch and repeat the bonding procedure according to the adhesive system
D. Place amalgam over the contaminated surface
Answer: Re-etch and repeat the bonding procedure according to the adhesive
system
Rationale: Salivary contamination can compromise the quality of the etched
substrate and adhesive interface. Reconditioning the surface according to the
manufacturer's adhesive protocol is preferable to bonding over a contaminated
surface.
7. Which property of resin composite is most directly responsible for the need
for incremental placement in deep posterior restorations?
A. Fluoride release
B. Chemical adhesion to dentin
C. Polymerization shrinkage and limitations of depth of cure
D. High radiopacity
Answer: Polymerization shrinkage and limitations of depth of cure
Rationale: Incremental placement can improve light penetration and curing
while reducing the effective volume of composite polymerized at one time,
thereby helping manage polymerization shrinkage stress.
8. A tooth has a deep carious lesion and symptoms consistent with reversible
pulpitis. After selective caries removal, the cavity is restored with a well-
sealed adhesive restoration. Why is an effective coronal seal particularly
important?
A. It increases enamel thickness
B. It prevents all future caries
C. It limits bacterial nutrient supply and further contamination of the dentin-pulp
complex
D. It eliminates occlusal forces
