4.2 Auxiliary Scope of Practice: DA, OA, DSA, RDA, RDAEF, RDH, and RDHAP
Key Takeaways
No California dental assistant may diagnose, plan treatment, cut tissue, prescribe, start nitrous oxide, give anesthesia or sedation, or place, finish, or remove permanent restorations (B&P § 1750.1(d)).
Only RDAs, RDAEFs, RDHs, and RDHAPs may place pit and fissure sealants in California (B&P § 1750.1(f)).
An unlicensed California dental assistant must complete a two-hour Dental Practice Act course and hold BLS certification within one year of first employment (B&P § 1750(f)).
California RDHs need a DHBC-approved course and direct supervision for soft-tissue curettage, local anesthesia, and nitrous oxide (B&P § 1909).
An RDHAP who treats a patient 18 months or more after first providing services needs written verification of a dentist or physician examination (B&P § 1931).
Why the categories matter
Knowledge statement K1081 asks for "the scope of practice for auxiliaries." Exam questions usually give a duty and ask who may perform it, or give a category and ask which duty is off-limits. Two lists anchor everything else.
Duties no dental assistant may perform
B&P § 1750.1(d) excludes these from dental assistants, orthodontic assistants, and sedation assistants unless another law allows them:
- Diagnosis and comprehensive treatment planning.
- Placing, finishing, or removing permanent restorations.
- Surgery or cutting of hard or soft tissue, including extractions and suturing.
- Prescribing medication.
- Starting the flow of nitrous oxide and oxygen.
- Administering local or general anesthesia or sedation.
What a dental hygienist's practice excludes
B&P § 1908(b) excludes diagnosis and comprehensive treatment planning, permanent restorations, surgery or cutting, prescribing, and anesthesia or sedation, except nitrous oxide and local anesthesia under § 1909.
Duty ladder
| Category | Key duties | Supervision and conditions |
|---|---|---|
| Dental assistant (DA), unlicensed | Extraoral duties, sterilization, lab work, intraoral and extraoral photos; radiographs after a radiation safety course | General (§ 1750.1(a)) |
| Topical agents including fluoride; impressions for non-prosthodontic appliances; bite registrations; rubber dam; matrices; light-curing; remove post-extraction dressings and sutures after the dentist inspects; place and remove ortho separators; remove ligature ties and archwires; place monitoring sensors; give oxygen in an emergency | Direct (§ 1750.1(b)) | |
| Orthodontic assistant (OA) permit | DA duties plus preparing and etching teeth, sizing and fitting bands, positioning and curing brackets after the dentist approves placement, removing bands and brackets, ligating archwires, ultrasonic removal of cement | Direct; permit displayed (§ 1750.3) |
| Dental sedation assistant (DSA) permit | Monitoring sedated patients with pulse oximetry, ECG, and capnography; drawing drugs the dentist verifies; adding drugs to IV lines after the initial dose; removing IV lines | Direct, with the dentist at chairside during sedation (§ 1750.5) |
| Registered dental assistant (RDA) | All DA duties plus mouth-mirror inspection; bleaching; caries detection; CAD/CAM scans; pulp testing; bases, liners, etch, and bonding; direct provisional restorations and indirect provisionals including stainless steel crowns; dressings; drying canals; denture sore-spot adjustments and soft relines; coronal polishing | Dentist chooses general or direct (§ 1752.4(a), (d)) |
| After additional courses: sealants, ultrasonic cement removal on ortho patients, OA and DSA duties | § 1752.4(b) | |
| RDA in extended functions (RDAEF) | All RDA duties plus oral health assessments; gingival retraction; fitting and cementing endodontic points; post and core; final impressions for permanent indirect restorations and tooth-borne removable prostheses; placing, contouring, and finishing all direct restorations; adjusting and cementing permanent indirect restorations | Direct (§ 1753.5) |
| Choosing radiographs before the dentist's exam and placing interim therapeutic restorations in offices or telehealth public-health settings | § 1753.55 | |
| Registered dental hygienist (RDH) | Hygiene assessment and care plans; prophylaxis, scaling, and root planing; topical and subgingival agents; whitening trays | General (§ 1910) |
| Soft-tissue curettage, local anesthesia, nitrous oxide, after an approved course | Direct (§ 1909) | |
| Education and screenings; preventive services in public-health programs | No supervision (§ 1911) | |
| RDH in alternative practice (RDHAP) | Hygiene services in homes of homebound patients, schools, residential facilities, dental health professional shortage areas, dental offices, and certain clinics; may own an alternative practice | Independent, with a documented dentist relationship for referral and emergencies (§§ 1925–1926, 1930) |
Hygienists are licensed and disciplined by the Dental Hygiene Board of California (DHBC), not the Dental Board, although the dentist who supervises them remains accountable under the Dental Practice Act.
Training that must come first
- Every unlicensed DA, within one year of first employment: a Board-approved two-hour Dental Practice Act course and current BLS certification (§ 1750(f)(1)–(2)). The employer must tell the assistant about these requirements and keep proof.
- Before blood or saliva exposure: the DANB Infection Control exam or a Board-approved eight-hour infection control course (§§ 1750(c), 1755(b)).
- Before taking radiographs: a Board-approved radiation safety course, with the certificate displayed (§§ 1656, 1750(f)(3)).
- Before coronal polishing as an unlicensed DA: a Board-approved polishing course, taken after the eight-hour infection control course and BLS; the polishing must be done under direct supervision with the dentist evaluating each patient (§ 1750(f)(4)).
- Sealants: an RDA licensed on or after January 1, 2010 must complete a sealant course before the first renewal that requires CE (§ 1752.6).
- RDH curettage, local anesthesia, and nitrous oxide: a DHBC-approved course (§ 1909).
RDHAP details worth memorizing
- An RDHAP may treat a patient without proof of a prior dentist or physician exam. But if services continue 18 months or more after the first date of service, the RDHAP needs written verification of an exam by a California dentist or physician, including a prescription for hygiene services valid for up to two years (§ 1931).
- An RDHAP must document an existing relationship with at least one dentist for referral, consultation, and emergencies (§ 1930).
Common traps
- Final impressions: a DA may take impressions only for non-prosthodontic appliances. Final impressions for crowns belong to the RDAEF (and the dentist).
- Coronal polishing is not prophylaxis. Only a dentist or RDH performs oral prophylaxis. The teeth must be free of calculus before polishing.
- Permanent restorations: an RDAEF may place and finish direct restorations under direct supervision. An RDA may place only provisional restorations.
- Titles: anyone who holds a license lists it on a name tag (B&P § 680). An unlicensed DA must not be called an "RDA."
Which duty may a registered dental assistant in extended functions perform that a registered dental assistant may not?
Applying topical fluoride
Taking bite registrations
Fabricating and cementing a temporary crown
Placing, contouring, and finishing direct permanent restorations under direct supervision
An unlicensed dental assistant has worked in an office for 10 months. What must she have completed by the end of her first year of employment?
The RDA written examination
A Board-approved two-hour Dental Practice Act course and current basic life support certification
An orthodontic assistant permit
A four-hour course in local anesthesia
Which auxiliary may place pit and fissure sealants?
An unlicensed dental assistant working under direct supervision
An orthodontic assistant permit holder
A registered dental assistant who has completed the required sealant course
A dental sedation assistant permit holder
Sections you finish are checked off in the contents.