DHT ACTUAL EXAM |250 QUESTIONS AND ANSWERS WITH RATIONALE
.COURSE
.DHT
1. Question:
What is the primary etiologic factor in the development of periodontal disease?
a) Plaque biofilm
b) Dietary sugars
c) Smoking
d) Genetic predisposition
Answer: a) Plaque biofilm
Rationale: The primary cause of periodontal disease is plaque biofilm, a sticky layer of bacteria
that adheres to teeth. Other factors like smoking and genetic predisposition can exacerbate the
condition but are not primary causes.
2. Question:
Which type of fluoride is most effective for patients with high caries risk?
a) Sodium fluoride
b) Stannous fluoride
c) Acidulated phosphate fluoride
d) Neutral sodium fluoride
Answer: b) Stannous fluoride
Rationale: Stannous fluoride provides additional antimicrobial benefits, reducing plaque
bacteria and gingival inflammation, making it effective for high caries risk patients.
3. Question:
What is the appropriate sequence for using dental instruments during scaling?
a) Start with universal curettes, followed by scalers
b) Start with scalers, followed by universal curettes
c) Use ultrasonic scaler first, then hand instruments
d) Use hand instruments first, then ultrasonic scaler
Answer: c) Use ultrasonic scaler first, then hand instruments
,Rationale: Ultrasonic scalers remove the bulk of calculus and plaque efficiently. Hand
instruments are then used for detailed scaling and root planing.
4. Question:
Which of the following medications is most likely to cause gingival hyperplasia?
a) Ibuprofen
b) Amlodipine
c) Metformin
d) Tetracycline
Answer: b) Amlodipine
Rationale: Amlodipine, a calcium channel blocker, is associated with gingival hyperplasia. It
stimulates fibroblast proliferation and collagen synthesis in the gingiva.
5. Question:
Which bacteria are primarily associated with chronic periodontitis?
a) Streptococcus mutans
b) Treponema pallidum
c) Porphyromonas gingivalis
d) Actinomyces viscosus
Answer: c) Porphyromonas gingivalis
Rationale: Porphyromonas gingivalis is a key pathogen in the development of chronic
periodontitis due to its ability to evade host defenses and produce tissue-destroying enzymes.
6. Question:
What is the normal range of probing depths in a healthy periodontium?
a) 1–2 mm
b) 2–3 mm
c) 3–4 mm
d) 4–5 mm
Answer: b) 2–3 mm
Rationale: Healthy gingival sulcus depths typically range from 2 to 3 mm. Probing depths
exceeding this may indicate inflammation or periodontal disease.
,7. Question:
Which dental hygiene aid is most effective for cleaning interproximal spaces in a patient with
large embrasure spaces?
a) Dental floss
b) Toothpick
c) Interdental brush
d) Water flosser
Answer: c) Interdental brush
Rationale: Interdental brushes effectively clean large embrasure spaces and are easier to use for
patients with reduced dexterity or gingival recession.
8. Question:
What condition is characterized by a white, lacy pattern on the oral mucosa?
a) Leukoplakia
b) Lichen planus
c) Candidiasis
d) Geographic tongue
Answer: b) Lichen planus
Rationale: Lichen planus presents as a white, lacy pattern known as Wickham's striae, typically
affecting the buccal mucosa. It is an inflammatory condition often associated with immune
responses.
9. Question:
What is the best strategy to manage dental anxiety in patients?
a) Administer nitrous oxide immediately
b) Use tell-show-do techniques
c) Avoid discussing the procedure
d) Schedule long appointments to minimize visits
Answer: b) Use tell-show-do techniques
Rationale: The tell-show-do method reduces anxiety by explaining, demonstrating, and then
performing the procedure in a patient-friendly way. This builds trust and understanding.
, 10. Question:
Which type of caries affects the area beneath existing restorations?
a) Root caries
b) Incipient caries
c) Recurrent caries
d) Rampant caries
Answer: c) Recurrent caries
Rationale: Recurrent caries occur beneath or around the margins of restorations due to
inadequate seal or poor oral hygiene, leading to bacterial invasion.
11. Question:
Which vitamin deficiency is most commonly associated with angular cheilitis?
a) Vitamin C
b) Vitamin D
c) Vitamin B2
d) Vitamin E
Answer: c) Vitamin B2
Rationale: Angular cheilitis is often linked to riboflavin (Vitamin B2) deficiency. It can also
result from fungal infections or nutritional deficiencies.
12. Question:
What is the recommended fluoride concentration for community water fluoridation?
a) 0.5 ppm
b) 0.7 ppm
c) 1.0 ppm
d) 1.2 ppm
Answer: b) 0.7 ppm
Rationale: The optimal fluoride concentration in water (0.7 ppm) balances cavity prevention and
minimizes the risk of dental fluorosis.
13. Question:
Which of the following instruments is most effective for subgingival calculus removal?
a) Universal curette
b) Sickle scaler
.COURSE
.DHT
1. Question:
What is the primary etiologic factor in the development of periodontal disease?
a) Plaque biofilm
b) Dietary sugars
c) Smoking
d) Genetic predisposition
Answer: a) Plaque biofilm
Rationale: The primary cause of periodontal disease is plaque biofilm, a sticky layer of bacteria
that adheres to teeth. Other factors like smoking and genetic predisposition can exacerbate the
condition but are not primary causes.
2. Question:
Which type of fluoride is most effective for patients with high caries risk?
a) Sodium fluoride
b) Stannous fluoride
c) Acidulated phosphate fluoride
d) Neutral sodium fluoride
Answer: b) Stannous fluoride
Rationale: Stannous fluoride provides additional antimicrobial benefits, reducing plaque
bacteria and gingival inflammation, making it effective for high caries risk patients.
3. Question:
What is the appropriate sequence for using dental instruments during scaling?
a) Start with universal curettes, followed by scalers
b) Start with scalers, followed by universal curettes
c) Use ultrasonic scaler first, then hand instruments
d) Use hand instruments first, then ultrasonic scaler
Answer: c) Use ultrasonic scaler first, then hand instruments
,Rationale: Ultrasonic scalers remove the bulk of calculus and plaque efficiently. Hand
instruments are then used for detailed scaling and root planing.
4. Question:
Which of the following medications is most likely to cause gingival hyperplasia?
a) Ibuprofen
b) Amlodipine
c) Metformin
d) Tetracycline
Answer: b) Amlodipine
Rationale: Amlodipine, a calcium channel blocker, is associated with gingival hyperplasia. It
stimulates fibroblast proliferation and collagen synthesis in the gingiva.
5. Question:
Which bacteria are primarily associated with chronic periodontitis?
a) Streptococcus mutans
b) Treponema pallidum
c) Porphyromonas gingivalis
d) Actinomyces viscosus
Answer: c) Porphyromonas gingivalis
Rationale: Porphyromonas gingivalis is a key pathogen in the development of chronic
periodontitis due to its ability to evade host defenses and produce tissue-destroying enzymes.
6. Question:
What is the normal range of probing depths in a healthy periodontium?
a) 1–2 mm
b) 2–3 mm
c) 3–4 mm
d) 4–5 mm
Answer: b) 2–3 mm
Rationale: Healthy gingival sulcus depths typically range from 2 to 3 mm. Probing depths
exceeding this may indicate inflammation or periodontal disease.
,7. Question:
Which dental hygiene aid is most effective for cleaning interproximal spaces in a patient with
large embrasure spaces?
a) Dental floss
b) Toothpick
c) Interdental brush
d) Water flosser
Answer: c) Interdental brush
Rationale: Interdental brushes effectively clean large embrasure spaces and are easier to use for
patients with reduced dexterity or gingival recession.
8. Question:
What condition is characterized by a white, lacy pattern on the oral mucosa?
a) Leukoplakia
b) Lichen planus
c) Candidiasis
d) Geographic tongue
Answer: b) Lichen planus
Rationale: Lichen planus presents as a white, lacy pattern known as Wickham's striae, typically
affecting the buccal mucosa. It is an inflammatory condition often associated with immune
responses.
9. Question:
What is the best strategy to manage dental anxiety in patients?
a) Administer nitrous oxide immediately
b) Use tell-show-do techniques
c) Avoid discussing the procedure
d) Schedule long appointments to minimize visits
Answer: b) Use tell-show-do techniques
Rationale: The tell-show-do method reduces anxiety by explaining, demonstrating, and then
performing the procedure in a patient-friendly way. This builds trust and understanding.
, 10. Question:
Which type of caries affects the area beneath existing restorations?
a) Root caries
b) Incipient caries
c) Recurrent caries
d) Rampant caries
Answer: c) Recurrent caries
Rationale: Recurrent caries occur beneath or around the margins of restorations due to
inadequate seal or poor oral hygiene, leading to bacterial invasion.
11. Question:
Which vitamin deficiency is most commonly associated with angular cheilitis?
a) Vitamin C
b) Vitamin D
c) Vitamin B2
d) Vitamin E
Answer: c) Vitamin B2
Rationale: Angular cheilitis is often linked to riboflavin (Vitamin B2) deficiency. It can also
result from fungal infections or nutritional deficiencies.
12. Question:
What is the recommended fluoride concentration for community water fluoridation?
a) 0.5 ppm
b) 0.7 ppm
c) 1.0 ppm
d) 1.2 ppm
Answer: b) 0.7 ppm
Rationale: The optimal fluoride concentration in water (0.7 ppm) balances cavity prevention and
minimizes the risk of dental fluorosis.
13. Question:
Which of the following instruments is most effective for subgingival calculus removal?
a) Universal curette
b) Sickle scaler
