DANB CDA Exam 2026: RHS, ICE & GC Explained

Here is exactly how the DANB dental assisting exam works, and how to pass it, in just a few minutes. The credential most dental assistants are chasing is the CDA, Certified Dental Assistant, awarded by DANB, the Dental Assisting National Board. And the first thing to understand is that the CDA is not one exam. It is three separate component exams, and you must pass all three within a five-year period to earn the certification.

They are RHS, Radiation Health and Safety. ICE, Infection Control. And GC, General Chairside Assisting. You can sit them together or one at a time, at a test center or through remote online proctoring.

Here are the numbers, from DANB's own exam outlines. RHS is seventy-five questions in sixty minutes. ICE is also seventy-five questions in sixty minutes. GC is the big one, ninety-five questions in seventy-five minutes.

Taken together that is two hundred forty-five questions in one hundred ninety-five minutes, and once you are approved you have a sixty-day window in which to test. Now the scoring, and this is where most candidates get a nasty surprise. DANB does not report a percent correct. Your result is a scaled score running from one hundred to nine hundred, and you need four hundred to pass each component.

There is no percentage you can aim at, because the exams are computer adaptive: answer a question correctly and the next one gets harder, miss it and the next one gets easier, and your score depends on the difficulty of what you got right, not the raw count. Which leads to the single most important thing in this episode, straight from DANB. On a computer adaptive exam, the average candidate answers only about fifty percent of the questions correctly. Read that again.

If you walk out of that test center feeling like you were guessing at half of it and you are certain you failed, that is not evidence of failure. That is the exam working exactly as designed. A well-calibrated adaptive test keeps pushing you until it finds your ceiling, so it is supposed to feel hard the whole way through. Candidates talk themselves into a retake over a feeling that means nothing.

Before you can test at all, you have to qualify through one of three pathways. Pathway one is graduation from a dental assisting or dental hygiene program accredited by CODA. Pathway two is a high school diploma or equivalent plus at least three thousand five hundred hours of approved work experience. Pathway three covers dental school routes, including current or former CDA status and dental degree programs.

Every pathway also requires a current hands-on CPR or BLS certification from an accepted provider — and note the words hands-on. A purely online card will not satisfy it. Now, where are the points? Each component publishes its own weighting.

On RHS, half the exam is a single domain: purpose and technique, at fifty percent, with radiation characteristics and protection at twenty-five and infection prevention and control at twenty-five. On ICE, prevention of cross-contamination is the largest at thirty-four percent, then processing instruments and devices at twenty-six, with prevention of disease transmission and occupational safety at twenty percent each. And on GC, chairside dentistry alone is fifty percent, with evaluation and patient management at seventeen percent each and dental materials at sixteen. So across the whole CDA, two domains dominate: taking and evaluating images on RHS, and actual chairside procedure on GC.

Each is half of its own exam. If your study time is spread evenly across a textbook, it is not spread the way the exam is. Three real questions from the Quibank bank. First, from ICE.

After a steam cycle, the external chemical indicator printed on a sterilization pouch has changed color. What does that tell you? It tells you the package was exposed to the sterilization process — and nothing more. It does not tell you the contents are sterile.

Only a biological indicator, a spore test, can tell you that, and if a weekly spore test grows, you take the sterilizer out of service immediately and recall everything processed since the last passing test. Second, from RHS. A dental x-ray unit is operated at a source-to-receptor distance of eight inches. If you change to sixteen inches and alter nothing else, what happens to beam intensity at the receptor?

It falls to one-fourth. That is the inverse square law: double the distance and intensity drops by the square of the change, not in proportion to it. Halving would be the intuitive answer, and it is the wrong one. Third, from GC.

During a single-handed instrument transfer, where should the exchange happen? In the transfer zone, over the patient's chest and below the chin. Never over the patient's face — an instrument dropped there is the accident the zone system exists to prevent. So how do you prepare?

Four habits. First, drill practice questions until the reasoning is automatic. You cannot aim at a percentage on an adaptive exam, so aim at consistency instead: you want to be answering correctly on the harder items, not just the easy ones, because those are the items your scaled score is actually built from. Second, master the vocabulary.

Dental assisting is dense with word pairs that decide questions on their own. Chemical indicator versus biological indicator. Sanitize, disinfect, sterilize. Foreshortening versus elongation.

Regulated waste versus general waste. In a large share of questions every option is a real term, and the only thing being tested is whether you know which word means which thing. Third, take one component at a time and take the one you do daily first. If you are already setting up trays and passing instruments, GC rewards experience you already have.

If your office has you taking images every week, sit RHS while that knowledge is warm. Passing one component early also relieves the pressure on the five-year window. Fourth, weight your study time to the weighting. Chairside dentistry is half of GC and purpose and technique is half of RHS, so those two deserve the majority of your hours.

And on exam day, do not stall on a question that feels impossible — on an adaptive test, a hard question is a sign you are doing well. So remember. The CDA is three exams, RHS, ICE and GC, passed within five years. Two hundred forty-five questions and one hundred ninety-five minutes in total.

Scoring is scaled from one hundred to nine hundred with four hundred to pass, and because the exam adapts, the average candidate gets about half the questions wrong and still may pass. Chairside dentistry and imaging technique are each half of their exam. And you need a hands-on CPR card, not an online one. Start now with free dental assisting practice questions at quibank.com/en/dental-assistant.

Radiation health and safety, infection control, chairside assisting, oral anatomy and dental materials, in English, Chinese and Spanish, with no sign up.