To become a Certified Dental Assistant, or CDA, dental assistants must take the DANB (Dental Assisting National Board) CDA examination after they have completed an accredited dental assisting program, while those who have been trained on the job or have graduated from non-accredited programs are eligible to take the national certification examination after they have completed two years of full-time work experience as dental assistants. Some dentists are willing to pay a dental assistant-in-training that has a good attitude and work ethic.