Is it illegal to hire non-registered dental assistants?

I have volunteered for this dentist and there is something seriously wrong going on here. He is working with these two dental assistants, but both assistants did not even get education related to the field, and therefore not-registered. One of them is a college student and the other one is a housewife. I get a strong feeling that there is something wrong, but I want to make sure if it is illegal before I report them to police. This doctor also claims more amount to the insurance company than he's supposed to. He saves a lot of money by hiring non-registered assistants, and by claiming more amount for his dental work. I think it is very dangerous for them to deal with patients without proper education. Do you think I should report them? If I do, where should I report to?
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Actually it's not illegal...well it depends on the state. They all have different regulations. On the job training is ok in some states. From ADA: Dental assistants can become certified by passing an examination that evaluates their knowledge. Most dental assistants who choose to become nationally certified take the Dental Assisting National Board's (DANB) Certified Dental Assistant (CDA) examination. Becoming a Certified Dental Assistant (CDA) assures the public that the dental assistant is prepared to assist competently in the provision of dental care. Dental assistants are eligible to take the CDA examination if they have completed a dental assisting program accredited by the Commission on Dental Accreditation. Individuals 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 states also recognize passage of components of the CDA examination, such as the Radiation Health and Safety examination, or the Infection Control examination, for licensing and regulatory purposes. State regulations vary, and some states offer registration or licensure in addition to this national certification program.
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