Dental Assistant (CDA/DANB) practice questions and exam guide

In the FDI two-digit system, tooth 36 refers to the:

1. Upper right first molar
2. Upper left first molar
3. Lower left first molar
4. Lower right first molar

Answer: C — Lower left first molar

FDI first digit = quadrant (1=UR, 2=UL, 3=LL, 4=LR); second digit = tooth from midline. 36 = lower left, sixth from midline = first molar.

The surface of a posterior tooth that faces the tongue is the:

1. Buccal
2. Facial
3. Lingual
4. Incisal

Answer: C — Lingual

Lingual = tongue side on all teeth. Palatal is sometimes used for upper. Buccal/facial = cheek side. Incisal applies only to anterior teeth.

For an unconscious patient experiencing syncope, the assistant should:

1. Sit them upright
2. Begin chest compressions immediately
3. Give them sugar
4. Place them supine with legs slightly elevated, assess airway/breathing/circulation, and use ammonia inhalant

Answer: D — Place them supine with legs slightly elevated, assess airway/breathing/circulation, and use ammonia inhalant

Syncope: Trendelenburg/supine with legs up, monitor ABCs, ammonia inhalant. CPR only if pulseless.

A pediatric patient arrives with new bruising in unusual patterns and the parent's account is inconsistent. The dental team's legal obligation is generally to:

1. Ignore as not dental related
2. Post about it on social media
3. Confront the parent and refuse treatment
4. Recognize possible signs of abuse and follow state-mandated reporting procedures

Answer: D — Recognize possible signs of abuse and follow state-mandated reporting procedures

Dental professionals are mandated reporters in most jurisdictions; suspected child abuse must be reported per state law without confrontation.

A dental insurance UCR fee represents:

1. A government-set price
2. The patient's copay amount
3. The dentist's required charge
4. The Usual, Customary, and Reasonable fee that the insurer benchmarks against

Answer: D — The Usual, Customary, and Reasonable fee that the insurer benchmarks against

UCR = Usual, Customary, and Reasonable. It is the insurer's benchmark, not a regulated price.

ALARA stands for:

1. As Low As Reasonably Achievable
2. Always Lower Average Radiation Amount
3. Aim Low And Restart Always
4. Apply Lead Apron Routinely Always

Answer: A — As Low As Reasonably Achievable

B/C/D) Wrong. A) Correct — radiation safety principle.

Standard precautions mean:

1. Treat known infections only
2. Treat ALL body fluids as potentially infectious
3. PPE optional
4. Patient-specific

Answer: B — Treat ALL body fluids as potentially infectious

A/C/D) Wrong. B) Correct.

Per OSHA, employee training on the Bloodborne Pathogens Standard must occur:

1. Once at hire only
2. Only after an exposure incident
3. Every five years
4. At initial assignment AND at least annually thereafter

Answer: D — At initial assignment AND at least annually thereafter

BBP training is required at initial assignment and at least annually; documentation must be maintained.

If a biological monitor shows growth (sterilization failure), the office should:

1. Continue using the sterilizer until the next test
2. Ignore as a likely lab error
3. Sterilize twice as long going forward
4. Take the sterilizer out of service, recall and reprocess potentially affected loads, investigate the cause, retest, and document

Answer: D — Take the sterilizer out of service, recall and reprocess potentially affected loads, investigate the cause, retest, and document

Failed BI requires removing the sterilizer from service, recalling and reprocessing, and corrective action.

Alcohol-based hand rub is appropriate when:

1. Hands are visibly soiled with blood
2. Always preferred over soap and water
3. Hands are not visibly soiled and no contact with blood/saliva is suspected
4. Performing oral surgery scrub

Answer: C — Hands are not visibly soiled and no contact with blood/saliva is suspected

Soap and water is required when hands are visibly soiled or after contact with blood/saliva and for surgical scrubs; alcohol rub is for routine decontamination with non-soiled hands.

OSHA's Bloodborne Pathogens Standard (29 CFR 1910.1030) requires that hepatitis B vaccination:

1. Be paid for by the employee
2. Be mandatory for all employees
3. Be offered free of charge to employees with occupational exposure within 10 working days of assignment
4. Be administered only after an exposure incident

Answer: C — Be offered free of charge to employees with occupational exposure within 10 working days of assignment

Employer must offer HBV vaccine at no cost within 10 working days of assignment; the employee may decline by signed waiver.

Common errors?

Cone cut (mispositioned PID), elongation (steep vertical angle), foreshortening (shallow vertical angle), overlap (incorrect horizontal angle), blurring (motion).

Hand hygiene?

Soap + water (≥20 sec) when visibly soiled OR before surgery. Alcohol-based hand rub OK otherwise. Before + after every patient. Wash before gloving + after removal.

Digital vs. film?

Digital sensors: instant image, lower radiation dose (50-80% less), no chemicals. Phosphor plates: reusable, intermediate. Film: traditional, requires darkroom + chemicals.

Periodontium?

Tooth-supporting structures: gingiva (gums), periodontal ligament (PDL), cementum, alveolar bone.

What is informed consent?

A patient's voluntary agreement to a proposed treatment after being informed of the diagnosis, nature of the procedure, risks/benefits, and alternatives (including no treatment), in language they understand.

What does MRONJ stand for and what causes it?

Medication-Related Osteonecrosis of the Jaw; associated with antiresorptive drugs (bisphosphonates, denosumab) that suppress bone turnover, most often triggered by invasive procedures like extractions.