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NBDE PART 2 2025–2026 | 150 ACTUAL EXAM QUESTIONS WITH
VERIFIED CORRECT ANSWERS & DETAILED RATIONALES
(GRADED A+)100% CORRECT, GUARANTEE PASS
1.
Which restorative material releases fluoride to help prevent recurrent caries?
a) Amalgam
b) Composite resin
c) Glass ionomer (Correct Answer)
d) Gold inlay
Rationale: Glass ionomers release fluoride over time, which helps resist
secondary caries and is beneficial in high-caries-risk patients.
2.
What is the most likely cause of postoperative sensitivity in a composite
restoration?
a) C-factor
b) Over-etching
c) Polymerization shrinkage (Correct Answer)
d) Excessive polishing
Rationale: Composite shrinkage during curing creates microgaps at the
margins, leading to postoperative sensitivity.
3.
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Which condition presents with "onion-skin" radiographic appearance?
a) Osteosarcoma
b) Ewing’s sarcoma
c) Chronic sclerosing osteomyelitis
d) Proliferative periostitis (Correct Answer)
Rationale: Proliferative periostitis (Garre’s osteomyelitis) shows onion-skin
bone layering on radiographs.
4.
What is the most common site for oral squamous cell carcinoma?
a) Hard palate
b) Dorsal tongue
c) Ventrolateral tongue (Correct Answer)
d) Floor of the mouth
Rationale: The ventrolateral tongue is the most frequent site, followed by
the floor of the mouth.
5.
Which nerve is injured most often during extraction of mandibular third
molars?
a) Lingual nerve (Correct Answer)
b) Inferior alveolar nerve
c) Buccal nerve
d) Facial nerve
Rationale: The lingual nerve lies close to the lingual plate and is at higher
risk during flap reflection.
6.
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Which antibiotic is recommended for prophylaxis in patients allergic to
penicillin?
a) Clindamycin (Correct Answer)
b) Amoxicillin
c) Cephalexin
d) Doxycycline
Rationale: Clindamycin is the standard alternative for patients with
penicillin allergy requiring endocarditis prophylaxis.
7.
Which condition presents with “punched-out” radiolucencies in the jaws?
a) Multiple myeloma (Correct Answer)
b) Langerhans cell histiocytosis
c) Hyperparathyroidism
d) Osteosarcoma
Rationale: Multiple myeloma produces multiple well-defined, non-
corticated “punched-out” radiolucencies.
8.
Which occlusal scheme is most desirable in complete dentures?
a) Balanced occlusion (Correct Answer)
b) Group function
c) Canine guidance
d) Monoplane occlusion
Rationale: Balanced occlusion maintains simultaneous contact during
eccentric movements, improving denture stability.
9.
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Which is the most common malignant salivary gland tumor?
a) Mucoepidermoid carcinoma (Correct Answer)
b) Adenoid cystic carcinoma
c) Acinic cell carcinoma
d) Pleomorphic adenoma
Rationale: Mucoepidermoid carcinoma is the most frequent malignant
salivary gland tumor, affecting both major and minor glands.
10.
Which pulp test is most reliable for assessing pulp vitality?
a) Electric pulp test
b) Cold test
c) Heat test
d) Laser Doppler flowmetry (Correct Answer)
Rationale: Laser Doppler flowmetry is most accurate as it measures blood
flow, unlike subjective response tests.
11.
Which vitamin deficiency causes angular cheilitis and glossitis?
a) Vitamin B2 (Riboflavin) (Correct Answer)
b) Vitamin C
c) Vitamin D
d) Vitamin K
Rationale: Riboflavin deficiency produces angular cheilitis, glossitis, and
dermatitis.
12.
Which of the following is the main advantage of using MTA in endodontics?
a) High esthetics
NBDE PART 2 2025–2026 | 150 ACTUAL EXAM QUESTIONS WITH
VERIFIED CORRECT ANSWERS & DETAILED RATIONALES
(GRADED A+)100% CORRECT, GUARANTEE PASS
1.
Which restorative material releases fluoride to help prevent recurrent caries?
a) Amalgam
b) Composite resin
c) Glass ionomer (Correct Answer)
d) Gold inlay
Rationale: Glass ionomers release fluoride over time, which helps resist
secondary caries and is beneficial in high-caries-risk patients.
2.
What is the most likely cause of postoperative sensitivity in a composite
restoration?
a) C-factor
b) Over-etching
c) Polymerization shrinkage (Correct Answer)
d) Excessive polishing
Rationale: Composite shrinkage during curing creates microgaps at the
margins, leading to postoperative sensitivity.
3.
,2|Page
Which condition presents with "onion-skin" radiographic appearance?
a) Osteosarcoma
b) Ewing’s sarcoma
c) Chronic sclerosing osteomyelitis
d) Proliferative periostitis (Correct Answer)
Rationale: Proliferative periostitis (Garre’s osteomyelitis) shows onion-skin
bone layering on radiographs.
4.
What is the most common site for oral squamous cell carcinoma?
a) Hard palate
b) Dorsal tongue
c) Ventrolateral tongue (Correct Answer)
d) Floor of the mouth
Rationale: The ventrolateral tongue is the most frequent site, followed by
the floor of the mouth.
5.
Which nerve is injured most often during extraction of mandibular third
molars?
a) Lingual nerve (Correct Answer)
b) Inferior alveolar nerve
c) Buccal nerve
d) Facial nerve
Rationale: The lingual nerve lies close to the lingual plate and is at higher
risk during flap reflection.
6.
,3|Page
Which antibiotic is recommended for prophylaxis in patients allergic to
penicillin?
a) Clindamycin (Correct Answer)
b) Amoxicillin
c) Cephalexin
d) Doxycycline
Rationale: Clindamycin is the standard alternative for patients with
penicillin allergy requiring endocarditis prophylaxis.
7.
Which condition presents with “punched-out” radiolucencies in the jaws?
a) Multiple myeloma (Correct Answer)
b) Langerhans cell histiocytosis
c) Hyperparathyroidism
d) Osteosarcoma
Rationale: Multiple myeloma produces multiple well-defined, non-
corticated “punched-out” radiolucencies.
8.
Which occlusal scheme is most desirable in complete dentures?
a) Balanced occlusion (Correct Answer)
b) Group function
c) Canine guidance
d) Monoplane occlusion
Rationale: Balanced occlusion maintains simultaneous contact during
eccentric movements, improving denture stability.
9.
, 4|Page
Which is the most common malignant salivary gland tumor?
a) Mucoepidermoid carcinoma (Correct Answer)
b) Adenoid cystic carcinoma
c) Acinic cell carcinoma
d) Pleomorphic adenoma
Rationale: Mucoepidermoid carcinoma is the most frequent malignant
salivary gland tumor, affecting both major and minor glands.
10.
Which pulp test is most reliable for assessing pulp vitality?
a) Electric pulp test
b) Cold test
c) Heat test
d) Laser Doppler flowmetry (Correct Answer)
Rationale: Laser Doppler flowmetry is most accurate as it measures blood
flow, unlike subjective response tests.
11.
Which vitamin deficiency causes angular cheilitis and glossitis?
a) Vitamin B2 (Riboflavin) (Correct Answer)
b) Vitamin C
c) Vitamin D
d) Vitamin K
Rationale: Riboflavin deficiency produces angular cheilitis, glossitis, and
dermatitis.
12.
Which of the following is the main advantage of using MTA in endodontics?
a) High esthetics
