# RDA exam practice questions: Preventive, aesthetic and specialty procedures

Five original RDA exam practice questions on preventive, aesthetic and specialty procedures, each answered on this page with a rationale and a source.

Last updated: 2026-07-25.

## Question 1

Three weeks after placement, a sealant is missing from a lower first molar. The chart notes that the cotton roll was changed mid-procedure and the patient's tongue brushed the etched surface just before the material was flowed in. What was the error, and what should have been done?

- A. The etch time was too short; the tooth should have been etched for twice as long.
- B. The etched surface was contaminated; rinse, re-isolate, and re-etch.
- C. The sealant was cured too long; a shorter cure would preserve its flexibility.
- D. The tooth needed a separate bonding agent applied under the sealant material.

**Answer B:** The etched surface was contaminated; rinse, re-isolate, and re-etch.

A sealant bonds by flowing into etch-created porosity, so any saliva contact on the etched surface destroys the bond; the correct response is to rinse, re-isolate, and re-etch.

**Common trap:** re-drying a contaminated surface is the wrong answer every time — the surface, not the moisture, is what changed.

Source: Bird DL, Robinson DS. Modern Dental Assisting. Current edition, Elsevier — the standard clinical dental-assisting reference used for Areas 1–3…

## Question 2

An RDA who passed the RDA examination last month and holds no additional certificates is asked to etch the teeth, preposition the brackets for the dentist's approval, and place the archwires and ligature ties. What is the correct analysis?

- A. All three tasks are native RDA duties requiring no additional credential.
- B. None of the three is within RDA scope without an orthodontic assistant permit.
- C. Archwires and ligature ties are native RDA scope; the bonding steps are not.
- D. All three are permitted, because the dentist approves the bracket position before curing.

**Answer C:** Archwires and ligature ties are native RDA scope; the bonding steps are not.

Placing ligature ties and archwires is native RDA scope under BPC §1752.4(a)(18), while preparing teeth for bonding and prepositioning brackets belong to the orthodontic assistant permit under BPC §1750.3 or to an RDA who completed the Board-approved course in those duties under §1752.4(b)(2).

**Common trap:** the OA permit has its own prerequisites and its own separate written examination — passing the RDA exam alone does not authorize bracket work.

Source: [California Business & Professions Code §1752.4 — RDA duties and supervision levels. Subdivision (a) lists the RDA's duties, performed "under general…](https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?sectionNum=1752.4.&lawCode=BPC)

## Question 3

A Bakersfield general practice hires a dental assistant who is not licensed as an RDA. She has completed the eight-hour infection control course, holds current basic life support certification, and has just finished a Board-approved coronal polishing course. The dentist works in the same treatment facility and evaluates each patient after the procedure. The office manager tells her that polishing has to wait until she passes the RDA exam. Who is right?

- A. The office manager — since January 1, 2025, coronal polishing may be performed only by an RDA, RDAEF, RDH, or RDHAP, so she must wait.
- B. The assistant — BPC §1750(f)(4) lets an unlicensed assistant who completed a Board-approved course polish under direct supervision.
- C. The office manager — an unlicensed assistant may polish only under general supervision, and this dentist is providing direct supervision.
- D. The assistant — but only after the Board issues her a separate coronal polishing permit on top of the course certificate.

**Answer B:** The assistant — BPC §1750(f)(4) lets an unlicensed assistant who completed a Board-approved course polish under direct supervision.

Since January 1, 2025, BPC §1750(f)(4) lets an unlicensed dental assistant perform coronal polishing before RDA licensure after completing a Board-approved coronal polishing course, and it writes the conditions into the statute: the polishing is performed under direct supervision, and the dentist must at minimum evaluate each patient after the procedure. The eight-hour infection control course and current basic life support certification are prerequisites to enrolling in the polishing course, and this assistant has both. Direct supervision means the dentist is physically present in the treatment facility, which the stem supplies.

**Common trap:** Option A is the single most common stale-prep answer in this subarea — "only an RDA may polish" was true before the SB 1453 restructure and is wrong now. It also borrows the wrong rule: the category restriction candidates are half-remembering belongs to sealants under BPC §1750.1(f), not to polishing. Option C inverts the supervision element — the RDA's own statutory duty list places polishing under general supervision at BPC §1752.4(a)(17), but the unlicensed-assistant lane is expressly direct supervision, and the Board's table carries the polishing row at direct supervision with a course required. Option D invents a credential: this lane is gated on a Board-approved course, not on a Board-issued permit.

Source: [California Business & Professions Code §1750 — unlicensed dental assistant: definition, employer duties, the eight-hour infection control course, and…](https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?sectionNum=1750.&lawCode=BPC)

## Question 4

In a San Jose general practice, the dentist examines a patient with a suspected cracked lower molar, orders pulp vitality testing on that tooth, and then leaves for a scheduled hospital consult. Nothing in the practice's written instructions requires direct supervision for this procedure. The RDA runs a cold test on the ordered tooth and on the contralateral control tooth. The suspect tooth gives a sharp response that lingers about 45 seconds after the refrigerant is removed. What should the RDA do?

- A. Wait until the dentist returns, because pulp vitality testing may only be performed with the dentist physically present in the facility.
- B. Record the stimulus, the tooth tested, the control tooth's response, and the lingering response, and report to the dentist.
- C. Chart the tooth as irreversible pulpitis, and note the lingering response, so the dentist can schedule endodontic treatment.
- D. Repeat the test with an electric pulp tester on the same tooth and record whichever result is easier to interpret.

**Answer B:** Record the stimulus, the tooth tested, the control tooth's response, and the lingering response, and report to the dentist.

"Pulp vitality testing and recording of findings" sits in the BPC §1752.4(a) general-supervision list as restructured by SB 1453 effective January 1, 2025, and the Board's Table of Permitted Duties effective that date marks the row "G," so the dentist's physical presence is not required unless the supervising dentist has determined under §1752.4(d) that this procedure requires direct supervision. What the RDA may not do is convert the finding into a diagnosis: "Diagnosis and comprehensive treatment planning" is on the never-delegable list at BPC §1750.1(d) for every assisting category. Results are always read against a normal control tooth, and a lingering response is a finding to be recorded and reported, not interpreted.

**Common trap:** Option A is the classic stale-prep answer — pre-2025 duty charts, including widely reposted 2019 tables, listed pulp vitality testing as a direct-supervision RDA duty, and SB 1453 moved it. Option C is the tempting clinical trap: the lingering-response pattern really does suggest irreversible pulpitis, but naming it is diagnosis and is never delegable. Option D discards the standardized record and cherry-picks a result, which defeats the point of recording findings.

Source: [California Business & Professions Code §1752.4 — RDA duties and supervision levels. Subdivision (a) lists the RDA's duties, performed "under general…](https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?sectionNum=1752.4.&lawCode=BPC)

## Question 5

An RDA in a Fresno office is polishing for a patient with moderate coffee stain on the facial surfaces of the maxillary anterior teeth. Tooth #8 carries a three-year-old composite restoration on the facial. Which approach best matches standard technique?

- A. Use a coarse pumice paste over every facial surface, including the composite, because heavier stain calls for a more aggressive abrasive agent.
- B. Use the least abrasive paste that removes the stain, switch to a non-abrasive agent on the composite, and keep the cup moving at low speed.
- C. Run a bristle brush with a fine paste along the gingival third of each of the anterior teeth, where the stain is heaviest.
- D. Run the handpiece at high speed with firm and continuous pressure on each surface, in order to shorten the appointment.

**Answer B:** Use the least abrasive paste that removes the stain, switch to a non-abrasive agent on the composite, and keep the cup moving at low speed.

Standard technique is to select the least abrasive agent that removes the stain, because every pass removes a thin layer of the fluoride-rich outer enamel. Composite, glass ionomer, porcelain, and gold are dulled and scratched by ordinary coarse pumice-based pastes, so a non-abrasive polishing agent such as an aluminum-oxide or tin-oxide paste is used on restorative surfaces. Low speed, light intermittent pressure, a constantly moving cup, and wet paste control the frictional heat that reaches the pulp. On the legal side, the RDA's coronal-polishing row is BPC §1752.4(a)(17) and the Board's table marks it G — general supervision — so the dentist need not be physically present unless this supervising dentist has required direct supervision under §1752.4(d). The D marking that circulates for polishing belongs to the unlicensed dental assistant lane at BPC §1750(f)(4), which does require direct supervision plus a Board-approved course and a per-patient dentist evaluation.

**Common trap:** Option A is "coarse works better," which is true only about speed of stain removal and false about everything else — it costs enamel and it damages the composite. Option C misplaces the bristle brush: it belongs on occlusal surfaces and in deep pits and grooves, never near the gingiva or on exposed root surfaces, where stiff bristles lacerate soft tissue and abrade cementum. Option D is the efficiency trap; sustained pressure and speed generate heat the patient feels and, at the extreme, pulpal damage.

Source: [California Business & Professions Code §§1740–1742 — dental auxiliaries: legislative intent and definitions, including direct supervision (§1741(k),…](https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?sectionNum=1741.&lawCode=BPC)

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Official reference: [Dental Board of California RDA Combined Written and Law and Ethics Examination Outline](https://www.dbc.ca.gov/formspubs/rda_exam_outline.pdf). Original exam-style questions written for study, never recalled exam content. Independent educational preparation, not legal or clinical advice, and not affiliated with or endorsed by the Dental Board of California or PSI. Confirm current requirements with the Dental Board of California.