INBDE (Integrated National Board Dental Examination) TEST
BANK EXAM TEST QUESTIONS AND ANSWERS WITH
100% VERIFIED SOLUTIONS PLUS RATIONALES.
1. Which cell type is primarily responsible for the formation of dentin?
A. Ameloblasts
B. Odontoblasts
C. Cementoblasts
D. Osteoblasts
Correct Answer: B
Rationale: Odontoblasts form dentin, while ameloblasts form enamel. Cementoblasts
produce cementum and osteoblasts form bone.
2. The most common cause of reversible pulpitis is:
A. Trauma
B. Deep caries
C. Bruxism
D. Periodontal disease
Correct Answer: B
Rationale: Deep caries irritate the pulp, leading to reversible inflammation. Trauma
and bruxism may contribute but are less common causes.
3. Which nerve provides sensory innervation to the maxillary teeth?
A. Inferior alveolar nerve
B. Lingual nerve
C. Superior alveolar nerves
D. Mental nerve
Correct Answer: C
Rationale: The superior alveolar nerves (branches of CN V2) supply the maxillary
teeth, while inferior alveolar supplies mandibular teeth.
4. What is the primary function of saliva?
A. Enamel formation
B. Lubrication and digestion
C. Tooth eruption
D. Bone remodeling
Correct Answer: B
Rationale: Saliva aids in lubrication, digestion, buffering acids, and antimicrobial
activity.
,5. Which bacteria is most associated with dental caries?
A. Porphyromonas gingivalis
B. Streptococcus mutans
C. Treponema denticola
D. Actinobacillus actinomycetemcomitans
Correct Answer: B
Rationale: Streptococcus mutans plays a key role in initiating dental caries through
acid production.
6. The periodontal ligament primarily functions to:
A. Produce enamel
B. Anchor the tooth to bone
C. Form dentin
D. Secrete saliva
Correct Answer: B
Rationale: The periodontal ligament attaches the tooth to alveolar bone and absorbs
occlusal forces.
7. Which vitamin deficiency is associated with scurvy and bleeding gums?
A. Vitamin A
B. Vitamin C
C. Vitamin D
D. Vitamin K
Correct Answer: B
Rationale: Vitamin C deficiency impairs collagen synthesis, leading to bleeding gums
and poor healing.
8. A radiolucent lesion at the apex of a non-vital tooth is most likely:
A. Dentigerous cyst
B. Radicular cyst
C. Odontoma
D. Ameloblastoma
Correct Answer: B
Rationale: Radicular cysts arise from non-vital teeth and appear radiolucent at the
apex.
9. Which anesthetic technique is used for mandibular molars?
A. PSA block
B. Infraorbital block
C. Inferior alveolar nerve block
D. Nasopalatine block
Correct Answer: C
, Rationale: The inferior alveolar nerve block anesthetizes mandibular molars and
associated structures.
10. 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.
11. Which condition is characterized by bone loss around teeth?
A. Gingivitis
B. Periodontitis
C. Pulpitis
D. Fluorosis
Correct Answer: B
Rationale: Periodontitis involves destruction of supporting bone, unlike gingivitis
which is limited to soft tissue.
12. What is the ideal fluoride concentration in drinking water?
A. 0.1 ppm
B. 0.7 ppm
C. 2.5 ppm
D. 5 ppm
Correct Answer: B
Rationale: 0.7 ppm is optimal for preventing caries while minimizing fluorosis risk.
13. 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, providing strong
anchorage.
14. What is the main cause of dry socket?
A. Infection
, B. Loss of blood clot
C. Nerve damage
D. Excess saliva
Correct Answer: B
Rationale: Dry socket occurs when the blood clot is dislodged, exposing bone and
nerves.
15. Which imaging technique provides a 3D view of dental structures?
A. Bitewing radiograph
B. Periapical radiograph
C. Panoramic radiograph
D. CBCT
Correct Answer: D
Rationale: Cone Beam CT (CBCT) provides 3D imaging useful for implants and
complex diagnosis.
16. Which condition presents with white patch lesions that cannot be scraped off?
A. Candidiasis
B. Leukoplakia
C. Lichen planus
D. Aphthous ulcer
Correct Answer: B
Rationale: Leukoplakia is a potentially premalignant lesion that cannot be wiped off.
17. What is the primary function of ameloblasts?
A. Dentin formation
B. Enamel formation
C. Cementum formation
D. Bone formation
Correct Answer: B
Rationale: Ameloblasts are responsible for producing enamel during tooth
development.
18. Which muscle is primarily responsible for closing the jaw?
A. Digastric
B. Mylohyoid
C. Masseter
D. Geniohyoid
Correct Answer: C
Rationale: The masseter elevates the mandible, enabling jaw closure.
BANK EXAM TEST QUESTIONS AND ANSWERS WITH
100% VERIFIED SOLUTIONS PLUS RATIONALES.
1. Which cell type is primarily responsible for the formation of dentin?
A. Ameloblasts
B. Odontoblasts
C. Cementoblasts
D. Osteoblasts
Correct Answer: B
Rationale: Odontoblasts form dentin, while ameloblasts form enamel. Cementoblasts
produce cementum and osteoblasts form bone.
2. The most common cause of reversible pulpitis is:
A. Trauma
B. Deep caries
C. Bruxism
D. Periodontal disease
Correct Answer: B
Rationale: Deep caries irritate the pulp, leading to reversible inflammation. Trauma
and bruxism may contribute but are less common causes.
3. Which nerve provides sensory innervation to the maxillary teeth?
A. Inferior alveolar nerve
B. Lingual nerve
C. Superior alveolar nerves
D. Mental nerve
Correct Answer: C
Rationale: The superior alveolar nerves (branches of CN V2) supply the maxillary
teeth, while inferior alveolar supplies mandibular teeth.
4. What is the primary function of saliva?
A. Enamel formation
B. Lubrication and digestion
C. Tooth eruption
D. Bone remodeling
Correct Answer: B
Rationale: Saliva aids in lubrication, digestion, buffering acids, and antimicrobial
activity.
,5. Which bacteria is most associated with dental caries?
A. Porphyromonas gingivalis
B. Streptococcus mutans
C. Treponema denticola
D. Actinobacillus actinomycetemcomitans
Correct Answer: B
Rationale: Streptococcus mutans plays a key role in initiating dental caries through
acid production.
6. The periodontal ligament primarily functions to:
A. Produce enamel
B. Anchor the tooth to bone
C. Form dentin
D. Secrete saliva
Correct Answer: B
Rationale: The periodontal ligament attaches the tooth to alveolar bone and absorbs
occlusal forces.
7. Which vitamin deficiency is associated with scurvy and bleeding gums?
A. Vitamin A
B. Vitamin C
C. Vitamin D
D. Vitamin K
Correct Answer: B
Rationale: Vitamin C deficiency impairs collagen synthesis, leading to bleeding gums
and poor healing.
8. A radiolucent lesion at the apex of a non-vital tooth is most likely:
A. Dentigerous cyst
B. Radicular cyst
C. Odontoma
D. Ameloblastoma
Correct Answer: B
Rationale: Radicular cysts arise from non-vital teeth and appear radiolucent at the
apex.
9. Which anesthetic technique is used for mandibular molars?
A. PSA block
B. Infraorbital block
C. Inferior alveolar nerve block
D. Nasopalatine block
Correct Answer: C
, Rationale: The inferior alveolar nerve block anesthetizes mandibular molars and
associated structures.
10. 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.
11. Which condition is characterized by bone loss around teeth?
A. Gingivitis
B. Periodontitis
C. Pulpitis
D. Fluorosis
Correct Answer: B
Rationale: Periodontitis involves destruction of supporting bone, unlike gingivitis
which is limited to soft tissue.
12. What is the ideal fluoride concentration in drinking water?
A. 0.1 ppm
B. 0.7 ppm
C. 2.5 ppm
D. 5 ppm
Correct Answer: B
Rationale: 0.7 ppm is optimal for preventing caries while minimizing fluorosis risk.
13. 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, providing strong
anchorage.
14. What is the main cause of dry socket?
A. Infection
, B. Loss of blood clot
C. Nerve damage
D. Excess saliva
Correct Answer: B
Rationale: Dry socket occurs when the blood clot is dislodged, exposing bone and
nerves.
15. Which imaging technique provides a 3D view of dental structures?
A. Bitewing radiograph
B. Periapical radiograph
C. Panoramic radiograph
D. CBCT
Correct Answer: D
Rationale: Cone Beam CT (CBCT) provides 3D imaging useful for implants and
complex diagnosis.
16. Which condition presents with white patch lesions that cannot be scraped off?
A. Candidiasis
B. Leukoplakia
C. Lichen planus
D. Aphthous ulcer
Correct Answer: B
Rationale: Leukoplakia is a potentially premalignant lesion that cannot be wiped off.
17. What is the primary function of ameloblasts?
A. Dentin formation
B. Enamel formation
C. Cementum formation
D. Bone formation
Correct Answer: B
Rationale: Ameloblasts are responsible for producing enamel during tooth
development.
18. Which muscle is primarily responsible for closing the jaw?
A. Digastric
B. Mylohyoid
C. Masseter
D. Geniohyoid
Correct Answer: C
Rationale: The masseter elevates the mandible, enabling jaw closure.
