NBDHE Test Dental Hygiene Care 1 — Questions and Answers
Question 1: When adapting a Gracey curette to the mesial surface of a mandibular molar during subgingival scaling, the terminal shank should be:
- Perpendicular to the gingival margin
- Parallel to the long axis of the tooth surface being scaled (Correct answer)
- At a 45-degree angle to the occlusal plane
- Parallel to the facial surface of the adjacent tooth
Correct answer: Parallel to the long axis of the tooth surface being scaled
The terminal shank of a Gracey curette must be kept parallel to the surface being scaled to ensure proper blade adaptation and effective calculus removal without traumatizing the periodontal tissues.
Question 2: Which clinical finding is the MOST reliable indicator of gingival inflammation during a periodontal assessment?
- Pocket depth greater than 3 mm
- Presence of supragingival calculus deposits
- Bleeding on probing (BOP) (Correct answer)
- Tooth mobility score of 1
Correct answer: Bleeding on probing (BOP)
Bleeding on probing reflects ulceration of the sulcular epithelium caused by active inflammation, making it the most direct and reliable clinical sign of gingival disease; calculus and pocket depth alone do not confirm current inflammation.
Question 3: The principle of selective polishing differs from routine polishing primarily because it:
- Uses a coarser prophy paste to save time
- Targets only teeth with clinically visible extrinsic stain, preserving fluoride-rich enamel (Correct answer)
- Is performed before scaling rather than after
- Requires an ultrasonic handpiece instead of a rubber cup
Correct answer: Targets only teeth with clinically visible extrinsic stain, preserving fluoride-rich enamel
Selective polishing avoids unnecessary abrasion by restricting rubber cup polishing to surfaces with extrinsic stain, thereby protecting the fluoride-rich outer enamel that would otherwise be abraded on clean surfaces.
Question 4: A patient reports a sharp tooth sensitivity to cold stimuli that resolves within 2–3 seconds after the stimulus is removed. This response pattern is MOST consistent with:
- Irreversible pulpitis
- Periapical abscess
- Cracked tooth syndrome
- Dentinal hypersensitivity (Correct answer)
Correct answer: Dentinal hypersensitivity
Dentinal hypersensitivity produces a short, sharp pain that disappears almost immediately after stimulus removal, consistent with the hydrodynamic theory in which fluid shifts in exposed dentinal tubules activate pulpal nociceptors; irreversible pulpitis and abscesses produce lingering or spontaneous pain.
Question 5: According to current evidence-based guidelines, which self-care method is MOST effective for removing interproximal biofilm?
- High-pressure water irrigation
- Rinsing with an essential oil mouthwash for 60 seconds
- Daily mechanical cleaning with floss or interdental brushes (Correct answer)
- Use of a tongue scraper morning and night
Correct answer: Daily mechanical cleaning with floss or interdental brushes
Mechanical disruption of interproximal biofilm with floss or interdental brushes once daily is the evidence-based standard; antimicrobial rinses and irrigation are adjuncts that do not substitute for mechanical removal of the biofilm matrix.
Question 6: During active periodontal debridement with a hand curette, the correct working angulation of the blade face against the tooth surface is:
- 0 to 20 degrees
- 45 to 90 degrees (Correct answer)
- 90 to 110 degrees
- 20 to 40 degrees
Correct answer: 45 to 90 degrees
A working angulation of 45–90 degrees (optimally 60–80 degrees) allows the curette blade to engage calculus with sufficient lateral pressure for effective removal; angles below 45 degrees cause the blade to slide over deposits, while angles above 90 degrees dig into the cementum.
NBDHE Test Dental Hygiene Care 1
When adapting a Gracey curette to the mesial surface of a mandibular molar during subgingival scaling, the terminal shank should be: