DANB CDA DANB CDA Dental Instruments and Equipment 2 — Questions and Answers
Question 1: What is the function of an amalgam carrier?
- To carve the final restoration
- To transport and dispense amalgam into the cavity (Correct answer)
- To mix amalgam components
- To burnish the finished restoration
Correct answer: To transport and dispense amalgam into the cavity
An amalgam carrier is a syringe-like instrument used to pick up freshly mixed amalgam and dispense it directly into the prepared cavity.
Question 2: Which type of matrix system is most commonly used for posterior composite restorations?
- Tofflemire matrix
- Sectional matrix system (Correct answer)
- Celluloid strip
- Copper band
Correct answer: Sectional matrix system
Sectional matrix systems (such as the Composi-Tight) are preferred for posterior composites because they create tight interproximal contacts and proper contours.
Question 3: The air-water syringe in a dental unit delivers which combination?
- Air and suction
- Water and suction
- Air, water, or a combination spray (Correct answer)
- Only compressed air
Correct answer: Air, water, or a combination spray
The air-water syringe (three-way syringe) can deliver air alone, water alone, or a combined air-water spray for rinsing and drying the operative field.
Question 4: What is the purpose of a dental dam clamp?
- To hold the dental dam frame in place
- To anchor the dental dam to the anchor tooth (Correct answer)
- To punch holes in the dental dam
- To cut the dental dam after use
Correct answer: To anchor the dental dam to the anchor tooth
A dental dam clamp (retainer) is placed on the anchor tooth (usually the most posterior tooth in the treatment area) to secure the dental dam in position.
Question 5: Which handpiece operates at speeds above 100,000 RPM?
- Straight handpiece
- Slow-speed handpiece
- High-speed (turbine) handpiece (Correct answer)
- Prophy angle
Correct answer: High-speed (turbine) handpiece
The high-speed air turbine handpiece operates between 250,000–400,000 RPM and is used for cutting enamel, dentin, and removing old restorations.
Question 6: What is the purpose of an explorer in a dental examination?
- To measure pocket depths
- To detect decay, calculus, and surface irregularities by tactile feel (Correct answer)
- To apply fluoride varnish
- To retract soft tissue
Correct answer: To detect decay, calculus, and surface irregularities by tactile feel
An explorer's sharp, thin tip allows the clinician to tactilely detect carious lesions, calculus deposits, overhanging margins, and surface defects.
DANB CDA DANB CDA Dental Instruments and Equipment 2
What is the function of an amalgam carrier?