RDA Dental Instruments and Tray Setups 2 — Questions and Answers
Question 1: Which instrument is used to condense (pack) amalgam into a prepared cavity?
- Spoon excavator
- Amalgam condenser (Correct answer)
- Burnisher
- Carver
Correct answer: Amalgam condenser
An amalgam condenser (plugger) is used to pack/condense amalgam into a cavity preparation, eliminating voids and adapting it to the walls.
The amalgam condenser (also called an amalgam plugger) has a flat or serrated working end used to push freshly mixed amalgam into the cavity preparation in increments, eliminating air voids and marginal gaps. After condensing, a burnisher is used to smooth the surface, and a carver is used to remove excess amalgam and restore occlusal anatomy before the material sets. The spoon excavator removes soft carious dentin.
Question 2: What is the purpose of the matrix band and retainer during an amalgam restoration?
- To isolate the tooth from saliva
- To create a temporary wall replacing the missing tooth wall during restoration placement (Correct answer)
- To etch the tooth surface
- To apply bonding agent
Correct answer: To create a temporary wall replacing the missing tooth wall during restoration placement
A matrix band and retainer (such as the Tofflemire retainer) create a temporary interproximal wall, providing a form to condense amalgam against when one or more walls of the cavity preparation are missing.
When a cavity preparation involves the proximal surface and a tooth wall is missing, a matrix band (thin metal or plastic strip) and retainer system (Tofflemire for amalgam, sectional matrix for composites) are placed to create the missing wall. This allows the restorative material to be condensed or placed against it, recreating proper tooth contour and contact. After the material sets sufficiently, the matrix is removed and the restoration is finished. Wedges are placed cervically to prevent overhangs.
Question 3: Which dental hand instrument has a blade used for removing soft, carious dentin?
- Amalgam condenser
- Spoon excavator (Correct answer)
- Explorer
- Mouth mirror
Correct answer: Spoon excavator
The spoon excavator has a spoon-shaped working end used to remove soft, carious dentin from cavity preparations.
Spoon excavators have a circular spoon-shaped blade that can be sharp or semi-sharp. They are used to scoop out softened, carious dentin from cavity preparations, remove temporary cement, and retrieve debris. They are part of basic operative dentistry setups. Other excavating instruments include hatchets and chisels. The explorer detects soft spots and cavities; the mouth mirror provides indirect vision and light reflection.
Question 4: What is the function of the periodontal probe?
- Detect caries on tooth surfaces
- Measure the depth of the gingival sulcus or periodontal pocket (Correct answer)
- Remove supragingival calculus
- Contour wax patterns
Correct answer: Measure the depth of the gingival sulcus or periodontal pocket
The periodontal probe is a calibrated instrument used to measure the depth of the gingival sulcus or periodontal pockets in millimeters, aiding in periodontal assessment.
The periodontal probe has a blunt, calibrated working end with millimeter markings (commonly at 3, 6, 8, and 11 mm or other interval patterns). It is inserted gently into the gingival sulcus and walked around each tooth at six sites (mesial, mid, distal — facial and lingual) to measure pocket depths. Normal sulcus depth is 1–3 mm; depths of 4 mm or greater indicate periodontal pocketing. Readings are recorded in the periodontal chart.
Question 5: Which instrument is used to carve and shape amalgam restorations to restore occlusal anatomy?
- Condenser
- Burnisher
- Carver (Correct answer)
- Hatchet
Correct answer: Carver
Carvers (such as the Hollenback carver or discoid/cleoid carver) are used to remove excess amalgam and shape the restoration to restore proper occlusal anatomy before the material fully hardens.
Amalgam carvers have sharp blades in various shapes (cleoid, discoid, Hollenback, interproximal) to remove excess amalgam and create proper anatomical contours including cusps, grooves, fossas, and marginal ridges. Carving must be done while the amalgam is still plastic but firm enough to hold shape. After carving, a burnisher may be used for final smoothing. Allowing the patient to articulate with articulating paper helps check occlusal contact accuracy.
Question 6: What is the correct sequence for passing a dental instrument to the dentist during a procedure?
- Handle end first with the working end pointing at the dentist
- Working end first directly into the dentist's hand
- Either end is acceptable
- Handing at the transfer zone with working end oriented for immediate use (Correct answer)
Correct answer: Handing at the transfer zone with working end oriented for immediate use
Instruments are passed in the transfer zone (below the patient's chin) with the working end oriented so the dentist can receive it and use it immediately without repositioning.
Efficient instrument transfer follows the four-handed dentistry principles. The instrument is passed in the transfer zone (between the patient's chin and chest) with the working end properly oriented — for example, with the handle toward the dentist's palm and the working end directed toward the tooth. The dentist signals the need for an exchange, the DA retrieves the used instrument with the pinky/ring finger, and simultaneously delivers the new instrument. Proper transfer reduces fatigue and procedure time.
RDA Dental Instruments and Tray Setups 2
Which instrument is used to condense (pack) amalgam into a prepared cavity?