ADEX Dental Hygiene Periodontal Instrumentation and Care Questions and Answers — Questions and Answers
Question 1: A dental hygienist is performing periodontal debridement on the facial aspect of tooth #30. To effectively remove a tenacious, sheet-like piece of subgingival calculus, which type of instrumentation stroke is most appropriate to initiate the removal process?
- A series of short, overlapping, horizontal strokes starting from the side edge of the deposit. (Correct answer)
- A single, long, continuous vertical stroke from the base of the pocket coronally.
- A light, sweeping oblique stroke across the entire deposit to smooth it.
- A push stroke directed apically to dislodge the calculus from the root surface.
Correct answer: A series of short, overlapping, horizontal strokes starting from the side edge of the deposit.
For tenacious or burnished calculus, using short, overlapping horizontal strokes starting from the edge of the deposit helps to break up the calculus into smaller, more manageable pieces for removal. A long vertical stroke may not engage the edge of the deposit effectively, and a light or push stroke would be ineffective and could even burnish the calculus further.
Question 2: When using a Gracey curette for subgingival calculus removal, what is the ideal angulation between the face of the blade and the tooth surface?
- 45 degrees
- 90 degrees
- Greater than 45 but less than 90 degrees (Correct answer)
- 0 degrees
Correct answer: Greater than 45 but less than 90 degrees
The optimal angulation for calculus removal with a Gracey curette is between 70 and 80 degrees. This angle allows the cutting edge to effectively 'bite' into the calculus deposit for removal. An angle less than 45 degrees will lead to burnishing, while an angle of 90 degrees or more can gouge the root surface and damage soft tissue.
Question 3: A patient with a history of a cardiac pacemaker presents for their routine periodontal maintenance appointment. Which of the following instruments is generally contraindicated for this patient without a medical consultation?
- Piezoelectric ultrasonic scaler
- Magnetostrictive ultrasonic scaler (Correct answer)
- Titanium implant scaler
- Hand-held sickle scaler
Correct answer: Magnetostrictive ultrasonic scaler
Historically, magnetostrictive ultrasonic scalers have been considered a potential source of electromagnetic interference with older models of cardiac pacemakers. While many modern pacemakers are shielded, it is standard practice to avoid using magnetostrictive ultrasonic devices on patients with pacemakers unless clearance has been given by their cardiologist. Piezoelectric scalers are generally considered safer but consultation is still best practice.
Question 4: Which of the following BEST describes the primary goal of periodontal debridement, distinguishing it from traditional scaling and root planing?
- Intentional removal of all cementum to create a glass-like root surface.
- Removal of only supragingival calculus deposits.
- Disruption and removal of biofilm and calculus while conserving cementum. (Correct answer)
- Removal of the soft tissue lining of the periodontal pocket.
Correct answer: Disruption and removal of biofilm and calculus while conserving cementum.
The contemporary understanding of periodontal therapy emphasizes that the goal is not the aggressive removal of cementum. Periodontal debridement focuses on the disruption and removal of bacterial biofilm and calculus deposits from the tooth surface and within the pocket, with the specific intent of preserving the underlying cementum.
Question 5: During instrumentation, a hygienist is using a modified pen grasp. The middle finger's primary role in this grasp is to:
- Roll the instrument handle for adaptation.
- Provide the main source of lateral pressure against the tooth.
- Rest lightly on the shank to guide the working-end and feel vibrations. (Correct answer)
- Stabilize the hand by resting on a nearby tooth surface.
Correct answer: Rest lightly on the shank to guide the working-end and feel vibrations.
In a correct modified pen grasp, the middle finger rests lightly on the instrument shank. This placement helps to guide the working-end and enhances tactile sensitivity, allowing the clinician to feel vibrations transmitted from the working-end to the shank. The thumb and index finger hold the instrument, and the ring finger serves as the fulcrum.
Question 6: A clinician is sharpening a Gracey 1/2 curette using a stationary flat stone and moving the instrument. To maintain the original design of the blade, the relationship between the face of the curette and the surface of the sharpening stone should be:
- 90 degrees
- Parallel, with the face tilted slightly away from the stone
- 100-110 degrees (Correct answer)
- 45 degrees
Correct answer: 100-110 degrees
When sharpening, the internal angle of the blade (between the face and the lateral surface) should be maintained at 70-80 degrees. To achieve this, the angle formed between the face of the curette blade and the stationary sharpening stone should be 100-110 degrees. This ensures the cutting edge is properly re-established without being weakened or excessively thinned.
ADEX Dental Hygiene Periodontal Instrumentation and Care Questions and Answers
A dental hygienist is performing periodontal debridement on the facial aspect of tooth #30.
To effectively remove a tenacious, sheet-like piece of subgingival calculus, which type of instrumentation stroke is most appropriate to initiate the removal process?