What’s on the DANB CDA Exam? 3 Components, 245 Questions, 11 Domains (2026)
The Dental Assisting National Board (DANB) Certified Dental Assistant (CDA) credential is earned by passing three component exams: General Chairside Assisting (GC) with 95 questions in 75 minutes, Infection Control (ICE) with 75 questions in 60 minutes, and Radiation Health and Safety (RHS) with 75 questions in 60 minutes. Taken together, that is 245 questions in 195 minutes inside a 60 day testing window. Each component is scored separately on a 100 to 900 scale, and 400 is the passing score. DANB’s GC outline took effect July 1, 2022, and its ICE and RHS outlines took effect March 12, 2025. Domain weights are percentages of each component, not of the whole exam: GC is Chairside Dentistry 50%, Evaluation 17%, Patient Management and Administration 17%, and Dental Materials 16%. ICE is Cross-contamination 34%, Processing Instruments and Devices 26%, Disease Transmission 20%, and Occupational Safety and Administration 20%. RHS is Purpose and Technique 50%, and Radiation Characteristics and Protection and Infection Prevention and Control at 25% each.
The 11 Domains and Their Weights
DANB publishes one outline per component, and each outline splits its component into weighted domains. The bars below put all 11 domains on one scale so you can compare them. Percentages are each domain’s share of its own component, as published by DANB, and the longest bar (50%) is drawn at about 90% width.
General Chairside Assisting (GC)
Chairside Dentistry is half of GC, so roughly 48 of the 95 questions come from it. It covers four handed dentistry: preparing the treatment room and trays, seating the patient, transferring instruments, and maintaining the field of operation with dental dams and moisture control. It also covers the intraoral procedures and armamentarium for restorative, surgical, and preventive care. Evaluation (17%) covers the preliminary examination, vital signs, health and dental histories, head and neck anatomy, charting oral conditions, treatment documentation, and recognizing medical emergencies. Patient Management and Administration (17%) combines patient behavior management and oral health education with legal records, OSHA, CDC, and HIPAA responsibilities, inventory, equipment maintenance, and emergency kit upkeep. Dental Materials (16%) covers impression materials, operative materials such as cements, composites, liners, and bonding agents, and laboratory materials such as gypsum and acrylics.
Infection Control (ICE)
Cross-contamination prevention is the largest ICE domain at 34%, about 26 of the 75 questions. It covers cleaning and disinfecting treatment areas and laboratories, preparing chemical disinfectants, surface barriers, tray setups, dental unit water lines, evacuation lines, and disposing of biohazardous waste. Processing Instruments and Devices (26%) follows the instrument pathway from transport through cleaning, packaging, sterilizer loading, storage, and interpreting sterilization monitoring results. Disease Transmission and Occupational Safety each carry 20%. The first covers modes of transmission, hand hygiene, personal protective equipment, and controlling aerosols and spatter. The second covers the OSHA Bloodborne Pathogens and Hazard Communication standards, CDC guidelines, exposure control plans, and the records a practice must keep.
Radiation Health and Safety (RHS)
Purpose and Technique is half of RHS, about 38 of 75 questions. It covers recognizing anatomical landmarks and conditions on images, the purpose of each image type from periapical and bitewing to panoramic and cone-beam computed tomography, what makes an image diagnostically acceptable, patient preparation and positioning, paralleling and bisecting angle technique, error correction, and mounting and viewing images. DANB’s RHS outline states the exam tests digital radiography only, with no conventional film concepts tested since July 7, 2022. Radiation Characteristics and Protection (25%) covers x-ray production, radiation biology, measurement, and patient and operator protection. Infection Prevention and Control (25%) applies disinfection and barrier practices to imaging equipment and receptors.
How to Use the Weights
Because DANB says every candidate sees the same percentage of questions from each domain, the weights are a reliable study map. Two domains each make up half of their component: Chairside Dentistry and RHS Purpose and Technique. Weak spots there cost more than anywhere else. But each component is scored on its own, and you need 400 on all three to earn the CDA. A strong GC score cannot cover for a weak RHS, so spread study time across components first, then weight by domain inside each one. The exams are also computer adaptive: DANB states that the average candidate answers about 50% of questions correctly, so expect questions to feel hard even when you are doing well.
Ready to test yourself against these domains? Start practicing with our DANB CDA practice test, or try a free DANB CDA practice test to sample questions from all three components first.
Frequently Asked Questions
How many questions are on the DANB CDA exam?
245 questions across three components: 95 for General Chairside Assisting, 75 for Infection Control, and 75 for Radiation Health and Safety. The total test time is 195 minutes. DANB notes that a small number of unscored pretest questions may appear on each exam.
What is the passing score on the DANB CDA exam?
400 on a scaled range of 100 to 900, earned separately on each of the three components. The score reflects the difficulty of the questions you answer correctly, so it is not a simple percentage.
Which domain is the largest on the CDA exam?
Within their components, Chairside Dentistry (GC) and Purpose and Technique (RHS) each make up 50%. Since GC has 95 questions, Chairside Dentistry is the largest single block at roughly 48 questions.
Does the RHS exam still test film radiography?
No. DANB’s outline states the RHS exam tests digital radiography only, with no conventional film concepts tested since July 7, 2022.
Sources
- danb.org, Certified Dental Assistant exam page
- DANB, General Chairside Assisting (GC) Exam Outline, effective 07/01/2022
- DANB, Infection Control (ICE) Exam Outline, effective 03/12/2025
- DANB, Radiation Health and Safety (RHS) Exam Outline, effective 03/12/2025
- danb.org, 4 important details to know about DANB exams
- DANB, Candidate Handbook (updated 6/22/2026)
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For educational and exam preparation purposes only. Not a substitute for formal clinical training.
