GC: Chairside Dentistry practice questions

Answer: B) Class V

• AIncorrect. That's pits and fissures.
• BCorrect. Gingival third of facial or lingual surfaces.
• CIncorrect. That includes an anterior incisal angle.
• DIncorrect. That's incisal edges or cusp tips.

Answer: B) In small increments

• AIncorrect. Small increments are used.
• BCorrect. To remove voids and excess mercury.
• CIncorrect. Condense it while plastic.
• DIncorrect. Amalgam isn't light-cured.

Answer: B) Maxillary root forceps

Extraction forceps are designed for a specific arch and tooth type. Maxillary root forceps are made to grip any root left in the maxillary arch.

• AIncorrect. Mandibular root forceps are angled for roots in the lower arch, not the maxilla.
• BCorrect. Maxillary root forceps are designed to grip any maxillary root.
• CIncorrect. Cowhorn beaks seat into the furcation of a molar. A single premolar root fragment has no furcation to engage.
• DIncorrect. A Cryer elevator is a pointed elevator for rotational force, typically on mandibular molar roots, and it does not grasp a root the way forceps do.

Answer: B) Modified pen grasp

High-speed handpieces are usually held with the modified pen grasp. It provides a stable fulcrum and fine control for cutting tooth structure.

• AIncorrect. In the palm grasp the instrument rests in the palm, held by the fingers. It is used for instruments such as rubber dam clamp forceps and extraction forceps, and it does not give the fine control needed with a handpiece.
• BCorrect. The thumb and index finger hold the handpiece opposite each other, the middle finger supports it, and the ring finger acts as a fulcrum. This gives the stability and precise control a high-speed handpiece needs.
• CIncorrect. In the palm-thumb grasp the instrument sits in the palm and the thumb steadies it. It is typically used for the air-water syringe and some hand instruments, not the high-speed handpiece.
• DIncorrect. Holding an instrument in a fist gives no finger rest or fulcrum, so it does not allow precise, controlled cutting.

Answer: A) Isolate the teeth being treated from saliva and the rest of the mouth

A dental dam's main job is to isolate the operating field: it keeps the teeth dry and free of saliva, improves visibility and access, and protects the airway and soft tissues. Retraction cord, bite blocks and matrices do other jobs.

• ACorrect. The dam isolates one or more teeth from the rest of the oral cavity. This keeps the field dry, improves access and visibility, protects the soft tissues and helps prevent aspiration of instruments and materials.
• BIncorrect. Pushing gingival tissue away from the finish line before an impression is the job of gingival retraction cord or other retraction systems, not the dam.
• CIncorrect. A bite block or mouth prop keeps the mouth open. The dam isolates the teeth but doesn't hold the jaw open.
• DIncorrect. A matrix band and wedge re-create the proximal wall and contour of a Class II restoration. The dam only isolates the field.

Answer: B) To prolong anesthesia and reduce bleeding

• AIncorrect. It lengthens it.
• BCorrect. It slows absorption.
• CIncorrect. That isn't the purpose.
• DIncorrect. That's topical anesthetic.

Answer: D) Plaque and extrinsic stain

• AIncorrect. That's cavity preparation.
• BIncorrect. That's scaling.
• CIncorrect. Polishing can't remove it.
• DCorrect. From the clinical crowns.

Answer: C) Gingiva, following the cervical constriction of the tooth

A looped Tofflemire band is funnel-shaped: the smaller circumference goes toward the gingiva to match the narrower cervical part of the tooth, and the larger circumference goes toward the occlusal surface.

• AIncorrect. The occlusal edge of the band is the larger circumference, because the crown is widest near the occlusal or contact area.
• BIncorrect. A wedge and burnishing of the band help achieve contact. The band's smaller edge is placed toward the cervical area, not the contact area.
• CCorrect. The crown narrows toward the cementoenamel junction. Placing the smaller circumference gingivally lets the band fit snugly at the cervical margin, while the larger edge fits the wider occlusal part of the crown.
• DIncorrect. The difference in circumference runs occlusal-to-gingival, not buccal-to-lingual. The retainer is usually on the buccal side, but that does not set the band's tapered orientation.

Answer: A) #15 blade

The #15 blade is small and curved, a scaled-down #10, and is the standard blade on a Bard-Parker handle for fine intraoral incisions such as raising a mucoperiosteal flap.

• ACorrect. The #15 is a small, curved blade, essentially a smaller version of the #10. It is used for fine incisions and is one of the blades most often used in oral surgery, including for raising mucoperiosteal flaps.
• BIncorrect. The #10 has a curved edge similar to the #15 but is much larger. It is used for longer skin incisions in general surgery and is too big for the confined oral cavity.
• CIncorrect. The #11 is a triangular blade with a sharp point and a straight edge. It is used for stab or sharply angled incisions, such as incising and draining an abscess, not for curved flap incisions.
• DIncorrect. The #22 is a large curved blade that fits a #4 handle and is used for large incisions in general surgery, not for intraoral flap procedures.

Answer: B) Pulpotomy

A pulpotomy removes only the coronal pulp and keeps the vital root pulp under a medicament. A pulpectomy, by contrast, removes the pulp from both the crown and the root canals.

• AIncorrect. A pulpectomy removes pulp tissue from both the pulp chamber and the root canals. It does not keep the radicular pulp.
• BCorrect. A pulpotomy removes the coronal pulp and keeps the vital radicular pulp, which is then covered with a medicament such as MTA. It is commonly done on primary molars with deep caries.
• CIncorrect. Indirect pulp treatment leaves a thin layer of affected dentin over a pulp that is not exposed. No pulp tissue is removed.
• DIncorrect. A direct pulp cap places material over a small exposure without removing the coronal pulp.