What Is the RDA Exam? State Licensure for Dental Assistants

The Registered Dental Assistant (RDA) credential is a state-issued dental assisting license. Unlike the DANB CDA — which is a single national credential — the RDA is administered separately in every state that licenses dental assistants, and the scope of practice, exam format, and prerequisites vary by state.

If you're prepping for the RDA, the very first thing to do is identify which state's RDA you're sitting. The California RDA is by far the most regulated and the highest volume; states like Texas, Washington, Oregon, Florida, New York, Arizona, and Colorado each run their own version with different content blueprints and practical requirements.

Why It Varies By State

Each state's dental practice act defines:

• Which procedures an RDA may perform under direct, indirect, or general supervision
• Whether expanded functions (coronal polishing, sealants, placing bases/liners, taking impressions for indirect restorations) are within scope
• Which exam — state-developed, DANB-administered, or a combination — fulfills the licensure requirement
• Whether a separate practical (clinical skills) exam is required in addition to the written

Translation: a "Registered Dental Assistant" in California, Texas, and Washington are three different credentials with three different scopes. Don't study from generic "RDA" material — study from the candidate handbook for your state's board.

The California RDA — The Most Common Example

California licenses more RDAs than any other state, so it's worth walking through. The CA RDA exam is administered by the Dental Board of California and consists of two parts:

Written Exam

• 150 questions, 3 hours, multiple choice
• Approximate domain weights:
  • General Chairside Assisting — ~35%
  • Dental Radiology — ~20%
  • Infection Control — ~20%
  • Patient Management — ~15%
  • Dental Materials & Lab Procedures — ~10%
• Passing score: 75% (verify the current standard with the Dental Board of California)
• The CA RDA also has heavy emphasis on the California Dental Practice Act — questions on supervision levels, scope, mandated reporting, and recordkeeping that are unique to California law

Practical Exam

The California RDA Practical assesses clinical skills hands-on. Common stations include:

• Coronal polishing
• Rubber dam placement
• Application of pit-and-fissure sealants
• Impression taking (alginate)
• Placement of bases, liners, and bonding agents

Both written and practical must be passed independently. You can sit them in either order.

Pathway

Most California RDA candidates qualify via:

• A Board-approved RDA program (most common path), plus
• California Dental Practice Act course completion, plus
• Current CPR/BLS, plus
• The Coronal Polishing and Pit-and-Fissure Sealant course completions if not covered by the program

How RDA Compares to CDA

| Feature | RDA | DANB CDA | |---|---|---| | Issued by | State board | DANB (national) | | Scope | Defined by state practice act | Defined by DANB + employer | | Exam | State-specific written + (often) practical | Three component exams (GC, RHS, ICE) | | Recognized in | The issuing state only | All 50 states recognize the CDA, but most still require a state license to practice | | Renewal | State-defined CE + renewal fee | Annual: 12 CDE + CPR | | Expanded functions | Often includes coronal polishing, sealants, etc. | Not in scope of CDA itself; varies by state |

Many candidates earn both the RDA (for the right to practice in their state) and the CDA (for portability and employer signaling).

How to Prepare

1. Pull your state's official candidate handbook first. Don't study from generic material until you've confirmed what's actually on your exam.
2. Drill the practice act. State-specific legal/scope questions are reliably tested and are the easiest points to lose if you skip them.
3. For California: study expanded functions thoroughly. Coronal polishing technique, sealant placement, and rubber dam are tested both written and practical — and the written questions test the same material the practical assesses, just in MCQ form.
4. Practical prep is hands-on. Written prep won't help you pass the practical. Find a study lab, a willing clinician mentor, or a board-approved course with mock practical sessions.

How CertCleared Helps

CertCleared's RDA track ships:

• 150-question RDA mock exam mirroring the written format
• FSRS-powered flashcards across all five domains
• A California Dental Practice Act content track for CA candidates
• State-specific tracks for the eight most common RDA states (Pro tier covers CA; Premium unlocks all eight)
• A coronal polishing & sealants reference, radiograph technique drills, and an expanded functions scope guide

Free tier gives you a starter General Chairside deck and 10 questions per day. Pro unlocks the CA RDA content; Premium adds all eight state tracks and a mandatory reporting & legal module.

CertCleared is an independent prep platform. We are not affiliated with, endorsed by, or sponsored by the Dental Board of California, DANB, or any state dental board. State-specific scope and exam details change — always verify with your state board's current candidate handbook before sitting.