NDHCE - Mock Exam Questions With
100% Correct Answers
National Dental Hygiene Certification Exam Preparation 2025
80 Unique Multiple-Choice Questions with Verified Answers and Detailed
Explanations
Instructions
This mock exam consists of 80 multiple-choice questions designed to prepare candidates
for the National Dental Hygiene Certification Exam (NDHCE). Each question includes
four answer options, with the correct answer marked. Detailed explanations provide the
rationale for the correct answer and clarify why other options are incorrect. The questions
cover key competencies, including clinical dental hygiene, community oral health, and
professional practice, as outlined in the NDHCE Blueprint for exams in 2025. Read each
question carefully and select the best answer.
1
,Mock Exam Questions
Question 1: A patient presents with a white, non-scrapable lesion on the lateral tongue.
What is the most likely diagnosis?
a. Oral candidiasis.
b. Leukoplakia. (Correct)
c. Geographic tongue.
d. Aphthous ulcer.
Rationale: Leukoplakia is a white, non-scrapable lesion often found on
the tongue or buccal mucosa, associated with chronic irritation or potential
malignancy. Oral candidiasis is scrapable, geographic tongue has a map-
like appearance, and aphthous ulcers are painful and not typically white.
Ref: General Dental Hygiene Knowledge
Question 2: What is the primary purpose of scaling and root planing in periodontal
therapy?
a. To whiten teeth.
b. To remove plaque and calculus from tooth surfaces. (Correct)
c. To reshape the tooth crown.
d. To apply fluoride for caries prevention.
Rationale: Scaling and root planing remove plaque, calculus, and bac-
terial toxins from tooth surfaces and roots to treat periodontal disease.
Whitening, reshaping, and fluoride application are not primary goals of
this procedure. Ref: General Dental Hygiene Knowledge
Question 3: A patient with diabetes mellitus is at increased risk for which oral condi-
tion?
a. Periodontal disease. (Correct)
b. Enamel hypoplasia.
c. Oral squamous cell carcinoma.
d. Amelogenesis imperfecta.
Rationale: Diabetes mellitus increases the risk of periodontal disease due
to impaired immune response and poor wound healing. Enamel hypoplasia,
carcinoma, and amelogenesis imperfecta are not directly linked to diabetes.
Ref: General Dental Hygiene Knowledge
Question 4: What is the recommended frequency for dental prophylaxis in a patient
with healthy gingiva?
a. Every 3 months.
b. Every 6 months. (Correct)
2
, c. Every 12 months.
d. Every 24 months.
Rationale: For patients with healthy gingiva, dental prophylaxis is rec-
ommended every 6 months to maintain oral health. More frequent visits
are needed for periodontal disease, while less frequent visits may be insuf-
ficient. Ref: General Dental Hygiene Knowledge
Question 5: Which tooth numbering system is used in the NDHCE examination?
a. Palmer notation.
b. Universal numbering system.
c. FDI two-digit system. (Correct)
d. ISO system.
Rationale: The NDHCE uses the FDI two-digit tooth numbering system,
as specified by the Federation of Dental Hygiene Regulators of Canada.
Palmer, Universal, and ISO systems are not used in the NDHCE. Ref:
Web ID 5
Question 6: A patient reports sensitivity to cold in tooth 2.1. What is the most likely
cause?
a. Dental caries. (Correct)
b. Periodontal abscess.
c. Bruxism.
d. Temporomandibular joint disorder.
Rationale: Sensitivity to cold in a specific tooth, such as 2.1 (maxillary
left central incisor), is commonly caused by dental caries, which expose
dentin or pulp. Periodontal abscesses cause gum pain, bruxism causes
wear, and TMJ disorders cause jaw pain. Ref: General Dental Hygiene
Knowledge
Question 7: What is the primary source of fluoride in community water fluoridation
programs?
a. Sodium fluoride. (Correct)
b. Calcium fluoride.
c. Potassium fluoride.
d. Magnesium fluoride.
Rationale: Sodium fluoride is commonly used in community water flu-
oridation to prevent dental caries. Calcium, potassium, and magnesium
fluoride are not typically used for this purpose. Ref: General Dental
Hygiene Knowledge
Question 8: A patient with gingivitis exhibits which clinical sign?
3
100% Correct Answers
National Dental Hygiene Certification Exam Preparation 2025
80 Unique Multiple-Choice Questions with Verified Answers and Detailed
Explanations
Instructions
This mock exam consists of 80 multiple-choice questions designed to prepare candidates
for the National Dental Hygiene Certification Exam (NDHCE). Each question includes
four answer options, with the correct answer marked. Detailed explanations provide the
rationale for the correct answer and clarify why other options are incorrect. The questions
cover key competencies, including clinical dental hygiene, community oral health, and
professional practice, as outlined in the NDHCE Blueprint for exams in 2025. Read each
question carefully and select the best answer.
1
,Mock Exam Questions
Question 1: A patient presents with a white, non-scrapable lesion on the lateral tongue.
What is the most likely diagnosis?
a. Oral candidiasis.
b. Leukoplakia. (Correct)
c. Geographic tongue.
d. Aphthous ulcer.
Rationale: Leukoplakia is a white, non-scrapable lesion often found on
the tongue or buccal mucosa, associated with chronic irritation or potential
malignancy. Oral candidiasis is scrapable, geographic tongue has a map-
like appearance, and aphthous ulcers are painful and not typically white.
Ref: General Dental Hygiene Knowledge
Question 2: What is the primary purpose of scaling and root planing in periodontal
therapy?
a. To whiten teeth.
b. To remove plaque and calculus from tooth surfaces. (Correct)
c. To reshape the tooth crown.
d. To apply fluoride for caries prevention.
Rationale: Scaling and root planing remove plaque, calculus, and bac-
terial toxins from tooth surfaces and roots to treat periodontal disease.
Whitening, reshaping, and fluoride application are not primary goals of
this procedure. Ref: General Dental Hygiene Knowledge
Question 3: A patient with diabetes mellitus is at increased risk for which oral condi-
tion?
a. Periodontal disease. (Correct)
b. Enamel hypoplasia.
c. Oral squamous cell carcinoma.
d. Amelogenesis imperfecta.
Rationale: Diabetes mellitus increases the risk of periodontal disease due
to impaired immune response and poor wound healing. Enamel hypoplasia,
carcinoma, and amelogenesis imperfecta are not directly linked to diabetes.
Ref: General Dental Hygiene Knowledge
Question 4: What is the recommended frequency for dental prophylaxis in a patient
with healthy gingiva?
a. Every 3 months.
b. Every 6 months. (Correct)
2
, c. Every 12 months.
d. Every 24 months.
Rationale: For patients with healthy gingiva, dental prophylaxis is rec-
ommended every 6 months to maintain oral health. More frequent visits
are needed for periodontal disease, while less frequent visits may be insuf-
ficient. Ref: General Dental Hygiene Knowledge
Question 5: Which tooth numbering system is used in the NDHCE examination?
a. Palmer notation.
b. Universal numbering system.
c. FDI two-digit system. (Correct)
d. ISO system.
Rationale: The NDHCE uses the FDI two-digit tooth numbering system,
as specified by the Federation of Dental Hygiene Regulators of Canada.
Palmer, Universal, and ISO systems are not used in the NDHCE. Ref:
Web ID 5
Question 6: A patient reports sensitivity to cold in tooth 2.1. What is the most likely
cause?
a. Dental caries. (Correct)
b. Periodontal abscess.
c. Bruxism.
d. Temporomandibular joint disorder.
Rationale: Sensitivity to cold in a specific tooth, such as 2.1 (maxillary
left central incisor), is commonly caused by dental caries, which expose
dentin or pulp. Periodontal abscesses cause gum pain, bruxism causes
wear, and TMJ disorders cause jaw pain. Ref: General Dental Hygiene
Knowledge
Question 7: What is the primary source of fluoride in community water fluoridation
programs?
a. Sodium fluoride. (Correct)
b. Calcium fluoride.
c. Potassium fluoride.
d. Magnesium fluoride.
Rationale: Sodium fluoride is commonly used in community water flu-
oridation to prevent dental caries. Calcium, potassium, and magnesium
fluoride are not typically used for this purpose. Ref: General Dental
Hygiene Knowledge
Question 8: A patient with gingivitis exhibits which clinical sign?
3
