LATEST 2026 INBDE (Integrated National Board Dental
Examination) COMPLETE EXAM QUESTIONS WITH 100%
VERIFIED ANSWERS PLUS RATIONALE| INSTANT
DOWNLOAD PDF.
1. Which of the following cells is primarily responsible for bone resorption?
A. Osteoblast
B. Osteocyte
C. Osteoclast
D. Fibroblast
Correct Answer: C
Rationale: Osteoclasts resorb bone, while osteoblasts form bone. Osteocytes maintain
bone, and fibroblasts produce connective tissue matrix.
2. A patient presents with reversible pulpitis. Which symptom is most characteristic?
A. Spontaneous severe pain
B. Pain lingering after stimulus removal
C. Sharp pain to cold that resolves quickly
D. No response to thermal stimuli
Correct Answer: C
Rationale: Reversible pulpitis typically causes sharp pain to cold that subsides
quickly. Lingering or spontaneous pain suggests irreversible pulpitis.
3. Which nerve provides sensory innervation to the mandibular teeth?
A. Infraorbital nerve
B. Posterior superior alveolar nerve
C. Inferior alveolar nerve
D. Greater palatine nerve
Correct Answer: C
Rationale: The inferior alveolar nerve supplies mandibular teeth. Other options
supply maxillary regions or soft tissues.
4. What is the primary function of saliva in oral health?
A. Mechanical chewing
B. Lubrication and buffering
C. Tooth mineralization only
D. Enamel formation
Correct Answer: B
Rationale: Saliva lubricates, buffers acids, and protects oral tissues. It also aids in
remineralization but is not solely responsible for it.
,5. Which bacterium is most associated with dental caries?
A. Porphyromonas gingivalis
B. Streptococcus mutans
C. Actinobacillus actinomycetemcomitans
D. Fusobacterium nucleatum
Correct Answer: B
Rationale: Streptococcus mutans is a primary cariogenic organism. Others are more
associated with periodontal disease.
6. Which type of hypersensitivity reaction is an immediate allergic response?
A. Type I
B. Type II
C. Type III
D. Type IV
Correct Answer: A
Rationale: Type I hypersensitivity is IgE-mediated and immediate. Type IV is delayed
and T-cell mediated.
7. What is the most common cause of pulp necrosis?
A. Trauma
B. Caries
C. Attrition
D. Abrasion
Correct Answer: B
Rationale: Dental caries is the leading cause of pulp necrosis due to bacterial
invasion.
8. Which restorative material releases fluoride?
A. Composite resin
B. Amalgam
C. Glass ionomer cement
D. Gold alloy
Correct Answer: C
Rationale: Glass ionomer cement releases fluoride, helping prevent recurrent caries.
9. What is the ideal angle for needle insertion in an inferior alveolar nerve block?
A. 15 degrees
B. 30 degrees
C. 45 degrees
D. Parallel to occlusal plane
, Correct Answer: D
Rationale: The needle is inserted parallel to the occlusal plane for proper inferior
alveolar nerve block technique.
10. Which condition is characterized by loss of attachment and bone destruction?
A. Gingivitis
B. Periodontitis
C. Pulpitis
D. Stomatitis
Correct Answer: B
Rationale: Periodontitis involves attachment loss and bone destruction, unlike
gingivitis which is reversible inflammation.
11. What is the primary component of enamel?
A. Collagen
B. Hydroxyapatite
C. Keratin
D. Elastin
Correct Answer: B
Rationale: Enamel is composed mainly of hydroxyapatite crystals, making it highly
mineralized.
12. Which drug is commonly used for conscious sedation in dentistry?
A. Lidocaine
B. Nitrous oxide
C. Amoxicillin
D. Ibuprofen
Correct Answer: B
Rationale: Nitrous oxide is widely used for conscious sedation due to its safety and
rapid onset.
13. Which vitamin deficiency leads to scurvy?
A. Vitamin A
B. Vitamin B12
C. Vitamin C
D. Vitamin D
Correct Answer: C
Rationale: Vitamin C deficiency causes scurvy, leading to bleeding gums and poor
wound healing.
, 14. What is the main function of dentin?
A. Provide esthetics
B. Protect pulp and support enamel
C. Produce saliva
D. Anchor teeth
Correct Answer: B
Rationale: Dentin supports enamel and protects the pulp through its tubular
structure.
15. Which radiographic feature indicates periapical pathology?
A. Radiopacity at apex
B. Widened periodontal ligament space
C. Thickened lamina dura
D. Enamel hypoplasia
Correct Answer: B
Rationale: A widened PDL space is an early sign of periapical pathology.
16. What is the mechanism of action of local anesthetics?
A. Block potassium channels
B. Block sodium channels
C. Increase calcium influx
D. Inhibit acetylcholine release
Correct Answer: B
Rationale: Local anesthetics block sodium channels, preventing nerve impulse
conduction.
17. Which tooth has the longest root?
A. Maxillary central incisor
B. Mandibular canine
C. Maxillary canine
D. Mandibular molar
Correct Answer: C
Rationale: The maxillary canine typically has the longest root.
18. What is the critical pH for enamel demineralization?
A. 7.0
B. 6.5
C. 5.5
D. 4.0
Correct Answer: C
Rationale: Enamel begins to demineralize at approximately pH 5.5.
Examination) COMPLETE EXAM QUESTIONS WITH 100%
VERIFIED ANSWERS PLUS RATIONALE| INSTANT
DOWNLOAD PDF.
1. Which of the following cells is primarily responsible for bone resorption?
A. Osteoblast
B. Osteocyte
C. Osteoclast
D. Fibroblast
Correct Answer: C
Rationale: Osteoclasts resorb bone, while osteoblasts form bone. Osteocytes maintain
bone, and fibroblasts produce connective tissue matrix.
2. A patient presents with reversible pulpitis. Which symptom is most characteristic?
A. Spontaneous severe pain
B. Pain lingering after stimulus removal
C. Sharp pain to cold that resolves quickly
D. No response to thermal stimuli
Correct Answer: C
Rationale: Reversible pulpitis typically causes sharp pain to cold that subsides
quickly. Lingering or spontaneous pain suggests irreversible pulpitis.
3. Which nerve provides sensory innervation to the mandibular teeth?
A. Infraorbital nerve
B. Posterior superior alveolar nerve
C. Inferior alveolar nerve
D. Greater palatine nerve
Correct Answer: C
Rationale: The inferior alveolar nerve supplies mandibular teeth. Other options
supply maxillary regions or soft tissues.
4. What is the primary function of saliva in oral health?
A. Mechanical chewing
B. Lubrication and buffering
C. Tooth mineralization only
D. Enamel formation
Correct Answer: B
Rationale: Saliva lubricates, buffers acids, and protects oral tissues. It also aids in
remineralization but is not solely responsible for it.
,5. Which bacterium is most associated with dental caries?
A. Porphyromonas gingivalis
B. Streptococcus mutans
C. Actinobacillus actinomycetemcomitans
D. Fusobacterium nucleatum
Correct Answer: B
Rationale: Streptococcus mutans is a primary cariogenic organism. Others are more
associated with periodontal disease.
6. Which type of hypersensitivity reaction is an immediate allergic response?
A. Type I
B. Type II
C. Type III
D. Type IV
Correct Answer: A
Rationale: Type I hypersensitivity is IgE-mediated and immediate. Type IV is delayed
and T-cell mediated.
7. What is the most common cause of pulp necrosis?
A. Trauma
B. Caries
C. Attrition
D. Abrasion
Correct Answer: B
Rationale: Dental caries is the leading cause of pulp necrosis due to bacterial
invasion.
8. Which restorative material releases fluoride?
A. Composite resin
B. Amalgam
C. Glass ionomer cement
D. Gold alloy
Correct Answer: C
Rationale: Glass ionomer cement releases fluoride, helping prevent recurrent caries.
9. What is the ideal angle for needle insertion in an inferior alveolar nerve block?
A. 15 degrees
B. 30 degrees
C. 45 degrees
D. Parallel to occlusal plane
, Correct Answer: D
Rationale: The needle is inserted parallel to the occlusal plane for proper inferior
alveolar nerve block technique.
10. Which condition is characterized by loss of attachment and bone destruction?
A. Gingivitis
B. Periodontitis
C. Pulpitis
D. Stomatitis
Correct Answer: B
Rationale: Periodontitis involves attachment loss and bone destruction, unlike
gingivitis which is reversible inflammation.
11. What is the primary component of enamel?
A. Collagen
B. Hydroxyapatite
C. Keratin
D. Elastin
Correct Answer: B
Rationale: Enamel is composed mainly of hydroxyapatite crystals, making it highly
mineralized.
12. Which drug is commonly used for conscious sedation in dentistry?
A. Lidocaine
B. Nitrous oxide
C. Amoxicillin
D. Ibuprofen
Correct Answer: B
Rationale: Nitrous oxide is widely used for conscious sedation due to its safety and
rapid onset.
13. Which vitamin deficiency leads to scurvy?
A. Vitamin A
B. Vitamin B12
C. Vitamin C
D. Vitamin D
Correct Answer: C
Rationale: Vitamin C deficiency causes scurvy, leading to bleeding gums and poor
wound healing.
, 14. What is the main function of dentin?
A. Provide esthetics
B. Protect pulp and support enamel
C. Produce saliva
D. Anchor teeth
Correct Answer: B
Rationale: Dentin supports enamel and protects the pulp through its tubular
structure.
15. Which radiographic feature indicates periapical pathology?
A. Radiopacity at apex
B. Widened periodontal ligament space
C. Thickened lamina dura
D. Enamel hypoplasia
Correct Answer: B
Rationale: A widened PDL space is an early sign of periapical pathology.
16. What is the mechanism of action of local anesthetics?
A. Block potassium channels
B. Block sodium channels
C. Increase calcium influx
D. Inhibit acetylcholine release
Correct Answer: B
Rationale: Local anesthetics block sodium channels, preventing nerve impulse
conduction.
17. Which tooth has the longest root?
A. Maxillary central incisor
B. Mandibular canine
C. Maxillary canine
D. Mandibular molar
Correct Answer: C
Rationale: The maxillary canine typically has the longest root.
18. What is the critical pH for enamel demineralization?
A. 7.0
B. 6.5
C. 5.5
D. 4.0
Correct Answer: C
Rationale: Enamel begins to demineralize at approximately pH 5.5.
