How to Become a Dental Assistant in Colorado

Who can apply

• Colorado does not license, register or permit dental assistants. You work under a licensed dentist.
• Intraoral work by a dental assistant is allowed only under the direct supervision of a dentist, in the dentist's regularly announced office (Board Rule 1.12).
• To take x-rays you must be at least 18 and complete at least 8.5 hours of radiation safety education and training (Board Rule 1.10).

Step by step

1. Get hired by a licensed Colorado dentist. No state application or exam is needed to start work.
2. Before taking x-rays, complete the radiation training in Rule 1.10 by one of three routes: an accredited or state-approved program, on-the-job training by a dentist or hygienist using a Board-approved module, or passing DANB's Radiation Health and Safety (RHS) exam or CDA.
3. Get written verification of the training, sign it, and keep one copy; your employer keeps the other in your employment file.
4. If the dentist will delegate nitrous oxide, complete at least 6 hours of nitrous oxide training (CODA program or continuing education) and give the dentist documented proof.
5. Optionally earn DANB credentials such as RHS or CDA. Colorado does not require them except as one way to meet the x-ray rule.

Training and exam

Training: No training is required to start basic assisting. To expose x-rays you need at least 8.5 hours: dental nomenclature (0.5 hr), machine operation exposure factors (2 hrs), operator and patient safety (1 hr), and practical or clinical experience (4 hrs of intraoral/extraoral technique, 0.25 hr film handling, 0.5 hr processing, 0.25 hr record documentation). It can be met through a CODA, Colorado higher-education, community college, private occupational school or equivalent out-of-state program; on-the-job training by a dentist or hygienist using a Board-approved module; or DANB's RHS or CDA exam. Nitrous oxide administration or monitoring needs at least 6 hours of training through a CODA program or continuing education.

Exam: No state exam. Passing DANB's Radiation Health and Safety (RHS) or Certified Dental Assistant (CDA) exam is one of three ways to meet the x-ray training rule, but not the only way.

What it costs in Colorado

Fixed amounts are set by the state. Items marked “your quote” are priced by private sellers, so enter what you’re quoted.

Good to know in Colorado

Three-month deadline for x-ray training: Dentists must make sure newly hired untrained staff meet the x-ray training rule within three months of starting a job in which they will take x-rays.

Training records: Your x-ray training verification must list the provider, hours, completion date, and the exposure techniques covered (bitewings, periapicals, occlusals, panoramic). The dentist must give it to the Board on request.

Nitrous oxide: A dentist may delegate administering and monitoring nitrous oxide/oxygen to a trained dental assistant under direct supervision, only after you provide documented proof of the training.

Where you can work: Dental assistant tasks must be done in the regularly announced office of a dentist who owns and practices in that office, unless you work as an unlicensed lab technician filling a valid lab work order.

Sources

• 3 CCR 709-1 Colorado Dental Board Rules (Colorado Secretary of State, version effective 08/30/2026), Rules 1.10, 1.12, 1.14(G)
• Colorado Secretary of State - 3 CCR 709-1 rule history
• Colorado Dental Board - Laws and Rules