ARKANSAS DENTAL HYGIENIST LICENSING
EXAM 70 QUESTIONS WITH ANSWERS AND
RATIONALES LATEST 2026-2027 UPDATE
Section I — Dental Hygiene Sciences
1. Which microorganism is most strongly associated with dental caries?
A. Porphyromonas gingivalis
B. Streptococcus mutans
C. Treponema denticola
D. Fusobacterium nucleatum
Correct Answer: B. Streptococcus mutans
Rationale: S. mutans is a major cariogenic bacterium that metabolizes fermentable
carbohydrates and produces acids that contribute to enamel demineralization.
2. The primary mineral component of tooth enamel is:
A. Collagen
B. Hydroxyapatite
C. Keratin
D. Elastin
Correct Answer: B. Hydroxyapatite
Rationale: Enamel consists primarily of highly mineralized hydroxyapatite crystals, making it
the hardest tissue in the human body.
3. Which tooth surface is generally most susceptible to plaque accumulation?
A. Smooth facial surfaces
B. Incisal edges
C. Gingival margin
D. Occlusal cusps
,Correct Answer: C. Gingival margin
Rationale: The gingival margin provides a protected area where bacterial biofilm can
accumulate if oral hygiene is inadequate.
4. What is the primary etiologic factor in gingivitis?
A. Trauma
B. Dental plaque biofilm
C. Malocclusion
D. Tooth wear
Correct Answer: B. Dental plaque biofilm
Rationale: Gingivitis is an inflammatory response of the gingival tissues to microbial biofilm.
5. Which periodontal structure attaches the tooth to the alveolar bone?
A. Enamel
B. Periodontal ligament
C. Pulp
D. Cementoenamel junction
Correct Answer: B. Periodontal ligament
Rationale: The periodontal ligament consists of connective tissue fibers that attach cementum to
alveolar bone and help support the tooth.
6. Which cells are primarily responsible for bone resorption?
A. Osteoblasts
B. Osteocytes
C. Osteoclasts
D. Fibroblasts
Correct Answer: C. Osteoclasts
Rationale: Osteoclasts are multinucleated cells responsible for resorbing mineralized bone
tissue.
, 7. Which vitamin is essential for normal collagen synthesis and wound healing?
A. Vitamin A
B. Vitamin B12
C. Vitamin C
D. Vitamin D
Correct Answer: C. Vitamin C
Rationale: Vitamin C is required for hydroxylation reactions involved in collagen formation.
Deficiency can impair wound healing and cause gingival bleeding.
8. What is the main function of saliva in caries prevention?
A. Increasing bacterial adhesion
B. Buffering acids and promoting remineralization
C. Removing all plaque
D. Preventing tooth eruption
Correct Answer: B. Buffering acids and promoting remineralization
Rationale: Saliva buffers acids, supplies calcium and phosphate, lubricates tissues, and
contributes to enamel remineralization.
9. Which tooth tissue contains odontoblasts?
A. Enamel
B. Dentin
C. Cementum
D. Alveolar bone
Correct Answer: B. Dentin
Rationale: Odontoblasts line the pulpal surface of dentin and are responsible for dentin
formation.
10. What is the normal primary function of gingival crevicular fluid?
EXAM 70 QUESTIONS WITH ANSWERS AND
RATIONALES LATEST 2026-2027 UPDATE
Section I — Dental Hygiene Sciences
1. Which microorganism is most strongly associated with dental caries?
A. Porphyromonas gingivalis
B. Streptococcus mutans
C. Treponema denticola
D. Fusobacterium nucleatum
Correct Answer: B. Streptococcus mutans
Rationale: S. mutans is a major cariogenic bacterium that metabolizes fermentable
carbohydrates and produces acids that contribute to enamel demineralization.
2. The primary mineral component of tooth enamel is:
A. Collagen
B. Hydroxyapatite
C. Keratin
D. Elastin
Correct Answer: B. Hydroxyapatite
Rationale: Enamel consists primarily of highly mineralized hydroxyapatite crystals, making it
the hardest tissue in the human body.
3. Which tooth surface is generally most susceptible to plaque accumulation?
A. Smooth facial surfaces
B. Incisal edges
C. Gingival margin
D. Occlusal cusps
,Correct Answer: C. Gingival margin
Rationale: The gingival margin provides a protected area where bacterial biofilm can
accumulate if oral hygiene is inadequate.
4. What is the primary etiologic factor in gingivitis?
A. Trauma
B. Dental plaque biofilm
C. Malocclusion
D. Tooth wear
Correct Answer: B. Dental plaque biofilm
Rationale: Gingivitis is an inflammatory response of the gingival tissues to microbial biofilm.
5. Which periodontal structure attaches the tooth to the alveolar bone?
A. Enamel
B. Periodontal ligament
C. Pulp
D. Cementoenamel junction
Correct Answer: B. Periodontal ligament
Rationale: The periodontal ligament consists of connective tissue fibers that attach cementum to
alveolar bone and help support the tooth.
6. Which cells are primarily responsible for bone resorption?
A. Osteoblasts
B. Osteocytes
C. Osteoclasts
D. Fibroblasts
Correct Answer: C. Osteoclasts
Rationale: Osteoclasts are multinucleated cells responsible for resorbing mineralized bone
tissue.
, 7. Which vitamin is essential for normal collagen synthesis and wound healing?
A. Vitamin A
B. Vitamin B12
C. Vitamin C
D. Vitamin D
Correct Answer: C. Vitamin C
Rationale: Vitamin C is required for hydroxylation reactions involved in collagen formation.
Deficiency can impair wound healing and cause gingival bleeding.
8. What is the main function of saliva in caries prevention?
A. Increasing bacterial adhesion
B. Buffering acids and promoting remineralization
C. Removing all plaque
D. Preventing tooth eruption
Correct Answer: B. Buffering acids and promoting remineralization
Rationale: Saliva buffers acids, supplies calcium and phosphate, lubricates tissues, and
contributes to enamel remineralization.
9. Which tooth tissue contains odontoblasts?
A. Enamel
B. Dentin
C. Cementum
D. Alveolar bone
Correct Answer: B. Dentin
Rationale: Odontoblasts line the pulpal surface of dentin and are responsible for dentin
formation.
10. What is the normal primary function of gingival crevicular fluid?
