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Make sure this is your exam — and that it is one exam, not three
This guide covers one test: the Registered Dental Assistant Combined Written and Law and Ethics Examination, required by Business and Professions Code section 1752.1, owned by the Dental Board of California, and delivered by PSI at computer testing centers.
Two structural facts trip up more candidates than any question on the exam does.
It is one exam. The old separate RDA General Written Examination and RDA Law and Ethics Examination were merged into this single test in 2018 — secondary accounts put the change at May 24, 2018. If a prep resource tells you to book two written exams, it is describing a system that no longer exists, and everything else it says about the exam is suspect too.
There is no practical. The RDA practical (hands-on) examination was suspended in 2017 and later eliminated. BPC §1752.1 now requires written evidence of your eligibility pathway plus this written examination, and nothing else. Any study material coaching typodont rehearsal — tray setups, dam placement, provisional fabrication, sealant placement on a model — is preparing you for a dead exam.
California also runs two other licensure exams whose names look similar in search results. They are different exams, run under different rules, and their materials will teach you the wrong things:
| Exam | Who takes it | Run by | Where to read about it |
|---|---|---|---|
| RDA Combined Written and Law and Ethics Exam (this guide) | Registered dental assistant candidates | Dental Board of California | dbc.ca.gov RDA applicant page |
| Dental Law and Ethics Exam | DDS/DMD licensure candidates | Dental Board of California | Dentist exam guide |
| RDH Laws and Ethics Written Exam | Dental hygienists | Dental Hygiene Board of California (a separate board) | RDH exam guide |
One more distinction worth holding onto: the dentist exam is entirely law and ethics. Yours is not. Laws and Regulations is one weighted area of your exam — 10%, roughly ten scored questions. Half of your exam is chairside dental procedures. Prep built for the dentist exam covers a tenth of what you need, and it asks from the supervising dentist's perspective rather than the assistant's.
Quick check before you spend money on prep: if a resource mentions a practical exam, two separate written exams, 140 or 150 questions, or "you need 75% to pass," it is out of date on the exam's basic shape. Every one of those was true once. None is true now.