CDA Dental Assistant practice questions with answers

Answer: C) Stensen's duct

• AIncorrect. That's from the sublingual gland.
• BIncorrect. That's a different gland.
• CCorrect. It opens near the maxillary second molar.
• DIncorrect. That drains tears.

Answer: A) Recommendations

• ACorrect. OSHA standards are enforceable regulations.
• BIncorrect. That describes OSHA standards.
• CIncorrect. They're recommendations.
• DIncorrect. They're recommendations for all settings.

Answer: B) To protect the prepared tooth and maintain its position until the final crown is cemented

A provisional crown protects the prepared tooth and pulp, keeps the tooth in position and the gingiva healthy, and gives function and appearance until the final crown is cemented.

• AIncorrect. Provisional materials and cements are designed for short-term use. A provisional crown is not a substitute for the final restoration.
• BCorrect. A provisional crown protects the pulp from thermal and other stimuli and supports gingival health. It also keeps the tooth from drifting or supra-erupting and restores function and appearance until the final crown is seated.
• CIncorrect. Gingival retraction for the final impression is done with retraction cord or other retraction materials, not with the provisional crown.
• DIncorrect. A provisional crown reduces sensitivity only while it covers the preparation. It does not permanently desensitize the tooth or remove the need for anesthesia.

Answer: A) Releasing pus to decompress the swollen tissue

Incision and drainage decompresses an abscess by releasing pus. The source of infection still needs root canal treatment or extraction, and spreading infections also need antibiotics.

• ACorrect. Incising the swelling lets pus drain, which relieves pressure and pain and speeds improvement.
• BIncorrect. The source of infection inside the tooth is removed by root canal treatment or extraction, not by draining the soft tissue.
• CIncorrect. I&D treats the swelling, but the involved tooth still needs definitive treatment such as root canal therapy or extraction.
• DIncorrect. In complicated or spreading infections, antibiotics are recommended along with surgical drainage, not replaced by it.

Answer: B) Root planing removes altered cementum or rough dentin to leave a smooth root surface

Scaling removes plaque, calculus and stain from tooth surfaces. Root planing goes further and removes altered cementum or rough dentin to leave a smooth root surface that helps tissues heal.

• AIncorrect. Scaling removes plaque, calculus and stain both above and below the gingiva. Root planing is not defined by where the calculus sits; its purpose is to smooth the root surface.
• BCorrect. Scaling removes plaque, calculus and stain from crown and root surfaces. Root planing then removes rough, toxin-laden cementum or dentin so the root is smooth, which makes plaque less likely to stick and supports healing.
• CIncorrect. Both procedures can be done with hand instruments (such as curettes), ultrasonic scalers, or both. The difference is the goal of each procedure, not the instrument used.
• DIncorrect. This reverses the roles. Root planing works on root surfaces, and removing extrinsic stain from crowns is done by scaling or coronal polishing.

Answer: D) It has a soothing (sedative) effect on the pulp

• AIncorrect. That's glass ionomer.
• BIncorrect. Eugenol inhibits resin setting.
• CIncorrect. It's temporary.
• DCorrect. It isn't used under composites.

Answer: A) Gown, mask, eyewear, gloves

• ACorrect. Gloves go on last.
• BIncorrect. Gloves go on last.
• CIncorrect. Gloves go on last.
• DIncorrect. Gloves go on last.

Answer: C) Clean first, then disinfect

• AIncorrect. It's clean, then disinfect.
• BIncorrect. Cleaning comes first.
• CCorrect. The second spray stays for the contact time.
• DIncorrect. It's clean, then disinfect.

Answer: D) Regulated medical waste

• AIncorrect. It's regulated medical waste.
• BIncorrect. It's regulated waste.
• CIncorrect. It's regulated waste.
• DCorrect. Dispose of it in a biohazard container.

Answer: A) Puncture-resistant, heavy-duty utility gloves

Manually cleaning contaminated instruments requires puncture-resistant, heavy-duty utility gloves to prevent sharps injuries. A mask, eye protection and a protective gown are also worn because splashing is likely.

• ACorrect. CDC recommends puncture-resistant, heavy-duty utility gloves for handling or manually cleaning contaminated instruments. A mask, eye protection and a gown should also be worn because splashing is likely.
• BIncorrect. Exam gloves are made for patient care. They are too thin to protect against punctures from sharp instruments during scrubbing.
• CIncorrect. Sterile gloves are for surgical procedures. They are not puncture-resistant, and sterility is not needed when cleaning contaminated items.
• DIncorrect. Overgloves are worn over exam gloves to prevent contamination of clean items during procedures. They offer no puncture or chemical protection.

Answer: A) With an amalgam separator that meets ISO 11143 and removes at least 95% of amalgam

The EPA dental effluent rule requires affected dental offices to use an ISO 11143 or ANSI/ADA 108-compliant amalgam separator with at least 95% removal efficiency, and to follow best management practices such as not flushing scrap amalgam and using line cleaners with a pH between 6 and 8.

• ACorrect. The rule requires an amalgam separator (or equivalent device) that is compliant with ANSI/ADA Specification 108 or ISO 11143 and has at least 95% removal efficiency.
• BIncorrect. The rule's best management practices prohibit discharging waste amalgam from chairside traps, screens or filters to the sewer (POTW).
• CIncorrect. The rule prohibits cleaning vacuum lines with oxidizing or acidic cleaners. Line cleaners must have a pH between 6 and 8.
• DIncorrect. A grease trap is not a certified amalgam separator and does not meet the rule's 95% removal requirement.

Answer: A) Mylohyoid (internal oblique) ridge

The mylohyoid (internal oblique) ridge is the radiopaque line on the lingual of the mandibular posterior region; the external oblique ridge is its buccal counterpart.

• ACorrect. The mylohyoid ridge runs along the lingual surface of the mandible beneath the premolars and molars and appears as a radiopaque line, often superimposed on the molar roots.
• BIncorrect. The external oblique ridge is also a radiopaque line in the molar region, but it is a continuation of the anterior ramus on the buccal surface of the mandible, usually seen higher, near the molar crowns.
• CIncorrect. The genial tubercles are lingual and radiopaque, but they are located at the midline of the anterior mandible and appear as a ring around the lingual foramen, not on molar images.
• DIncorrect. The mandibular canal appears as a radiolucent band bordered by thin radiopaque lines below the molar roots; it is an internal canal, not a lingual bony ridge.

Answer: C) Excessive vertical angulation

• AIncorrect. That causes overlap.
• BIncorrect. That causes elongation.
• CCorrect. This is foreshortening.
• DIncorrect. That causes blurring.

Answer: A) It produces a diagnostic image with less radiation exposure to the patient

The fastest receptor compatible with the diagnostic task (F-speed film or digital) is recommended because it needs less radiation to produce a diagnostic image. This lowers patient dose without compromising diagnostic quality.

• ACorrect. Faster receptors need less radiation to form a diagnostic image. FDA reports that switching from D-speed to F-speed film cut exposure by about 60 percent, and digital imaging can lower dose further. This is consistent with ALARA.
• BIncorrect. FDA reports no significant clinical difference in quality between D-speed film and E- or F-speed film. The benefit is lower dose, not better images.
• CIncorrect. Faster receptors lower the dose per image, but the dentist must still decide which radiographs are needed based on the patient's history and clinical exam.
• DIncorrect. FDA notes that a package of F-speed film costs slightly more (about $4) than the same package of D-speed film. The recommendation is based on reducing exposure, not cost.

Answer: A) The exposure control switch on the x-ray unit

Surfaces touched with gloved hands during radiography, such as the exposure switch and x-ray equipment, are clinical contact surfaces that need a barrier or disinfection between patients. Floors, walls and sinks are housekeeping surfaces.

• ACorrect. The operator touches the exposure switch during the procedure, often with contaminated gloves. CDC classifies switches and dental x-ray equipment as clinical contact surfaces, which should be covered with a barrier (changed between patients) or disinfected.
• BIncorrect. Floors are housekeeping surfaces, not clinical contact surfaces. They are cleaned routinely, not covered with barriers between patients.
• CIncorrect. Walls are housekeeping surfaces that are not touched during patient care. They are cleaned when visibly soiled or on a routine schedule, not barrier-protected.
• DIncorrect. Sinks are housekeeping surfaces. They are cleaned regularly but are not barrier-protected for each radiographic procedure.