National Dental Examining Board of
Canada (NDEB) Written Examination
Practice Questions And Correct Answers
(Verified Answers) Plus Rationales
2025|2026 Q&A | Instant Download Pdf
1. A 7-year-old presents with a deep carious lesion on a vital primary
molar with no spontaneous pain and no periapical pathology. Best
treatment?
A) Indirect pulp treatment with temporary restoration
B) Indirect pulp treatment with well-sealed definitive restoration
C) Direct pulp cap with calcium hydroxide
D) Pulpectomy
A well-sealed IPT preserves vitality and has high success in
asymptomatic primary teeth with deep caries; direct capping of
primary teeth is less predictable.
,2. A patient with a history of angina develops chest pain mid-
appointment. First action?
A) Give aspirin
B) Stop treatment, position comfortably, administer sublingual
nitroglycerin
C) Call EMS immediately
D) Give oxygen only
Initial management is to stop stressors and give nitroglycerin for
suspected angina; call EMS if pain persists after up to three doses at
5-minute intervals.
3. Which radiographic change most suggests external root resorption?
A) Uniform canal narrowing with intact outline
B) Irregular root surface outline with discontinuous canal space
C) Parallel PDL widening along entire root
D) Symmetrical lamina dura loss
External resorption alters the external root contour and disrupts the
canal outline; internal resorption produces a ballooning canal that
remains centered.
4. A 55-year-old on alendronate for osteoporosis needs an extraction.
Greatest risk factor for MRONJ?
A) Duration <6 months
B) Duration >4 years and concomitant corticosteroids
C) Oral route vs IV
, D) Age >50 alone
Longer antiresorptive exposure and corticosteroid use increase
MRONJ risk more than age or oral route alone.
5. Which organism is most implicated in localized aggressive
periodontitis (stage III, grade C; molar/incisor pattern)?
A) Porphyromonas gingivalis
B) Aggregatibacter actinomycetemcomitans
C) Treponema denticola
D) Tannerella forsythia
A. actinomycetemcomitans is classically associated with
molar/incisor pattern aggressive periodontitis.
6. A mandibular complete denture repeatedly dislodges during speech.
Most likely cause?
A) Excessive vertical dimension
B) Overextended lingual flange encroaching on mylohyoid
C) Insufficient labial flange thickness
D) Lack of posterior palatal seal
Lingual flange overextension in the mylohyoid region destabilizes
mandibular dentures during function and speech.
7. Which edge color indicates the end of an endodontic K-file size 40?
A) Red
B) Black
C) Yellow
, D) Green
ISO color code: 30 blue, 35 green, 40 black, 45 white, etc.
8. An ulcer with rolled, indurated borders on lateral tongue in a smoker
>3 weeks. Next step?
A) Prescribe topical steroid
B) Reassure and review in 4 weeks
C) Incisional biopsy
D) Culture for Candida
Persistent indurated ulcer in high-risk site warrants prompt biopsy to
rule out SCC.
9. After an inferior alveolar nerve block, the patient has facial paralysis
on that side. Cause?
A) Needle entry too anterior
B) Deposition within the parotid capsule affecting facial nerve
C) Intraneural injection of IAN
D) Allergy to epinephrine
Over-insertion posteriorly can reach the parotid gland where CN VII
branches, causing transient paralysis.
10. Best fluoride regimen for high-caries-risk adult with xerostomia?
A) 1000 ppm toothpaste once daily
B) 5000 ppm fluoride toothpaste twice daily plus quarterly varnish
C) Weekly fluoride rinse only
D) Varnish once per year only
Canada (NDEB) Written Examination
Practice Questions And Correct Answers
(Verified Answers) Plus Rationales
2025|2026 Q&A | Instant Download Pdf
1. A 7-year-old presents with a deep carious lesion on a vital primary
molar with no spontaneous pain and no periapical pathology. Best
treatment?
A) Indirect pulp treatment with temporary restoration
B) Indirect pulp treatment with well-sealed definitive restoration
C) Direct pulp cap with calcium hydroxide
D) Pulpectomy
A well-sealed IPT preserves vitality and has high success in
asymptomatic primary teeth with deep caries; direct capping of
primary teeth is less predictable.
,2. A patient with a history of angina develops chest pain mid-
appointment. First action?
A) Give aspirin
B) Stop treatment, position comfortably, administer sublingual
nitroglycerin
C) Call EMS immediately
D) Give oxygen only
Initial management is to stop stressors and give nitroglycerin for
suspected angina; call EMS if pain persists after up to three doses at
5-minute intervals.
3. Which radiographic change most suggests external root resorption?
A) Uniform canal narrowing with intact outline
B) Irregular root surface outline with discontinuous canal space
C) Parallel PDL widening along entire root
D) Symmetrical lamina dura loss
External resorption alters the external root contour and disrupts the
canal outline; internal resorption produces a ballooning canal that
remains centered.
4. A 55-year-old on alendronate for osteoporosis needs an extraction.
Greatest risk factor for MRONJ?
A) Duration <6 months
B) Duration >4 years and concomitant corticosteroids
C) Oral route vs IV
, D) Age >50 alone
Longer antiresorptive exposure and corticosteroid use increase
MRONJ risk more than age or oral route alone.
5. Which organism is most implicated in localized aggressive
periodontitis (stage III, grade C; molar/incisor pattern)?
A) Porphyromonas gingivalis
B) Aggregatibacter actinomycetemcomitans
C) Treponema denticola
D) Tannerella forsythia
A. actinomycetemcomitans is classically associated with
molar/incisor pattern aggressive periodontitis.
6. A mandibular complete denture repeatedly dislodges during speech.
Most likely cause?
A) Excessive vertical dimension
B) Overextended lingual flange encroaching on mylohyoid
C) Insufficient labial flange thickness
D) Lack of posterior palatal seal
Lingual flange overextension in the mylohyoid region destabilizes
mandibular dentures during function and speech.
7. Which edge color indicates the end of an endodontic K-file size 40?
A) Red
B) Black
C) Yellow
, D) Green
ISO color code: 30 blue, 35 green, 40 black, 45 white, etc.
8. An ulcer with rolled, indurated borders on lateral tongue in a smoker
>3 weeks. Next step?
A) Prescribe topical steroid
B) Reassure and review in 4 weeks
C) Incisional biopsy
D) Culture for Candida
Persistent indurated ulcer in high-risk site warrants prompt biopsy to
rule out SCC.
9. After an inferior alveolar nerve block, the patient has facial paralysis
on that side. Cause?
A) Needle entry too anterior
B) Deposition within the parotid capsule affecting facial nerve
C) Intraneural injection of IAN
D) Allergy to epinephrine
Over-insertion posteriorly can reach the parotid gland where CN VII
branches, causing transient paralysis.
10. Best fluoride regimen for high-caries-risk adult with xerostomia?
A) 1000 ppm toothpaste once daily
B) 5000 ppm fluoride toothpaste twice daily plus quarterly varnish
C) Weekly fluoride rinse only
D) Varnish once per year only
