The scope of practice of an oral health care provider is essentially divided into three tiers.
Dental assistants and dental hygienists can provide care that is reversible. Any act that is reversible can be done at that level according to the regulations. Obviously, assistants have a very restricted scope of what they can provide directly on patients. Hygienists have a much broader scope, but the services they are providing are essentially reversible.
Dental therapists are intermediate mid-level providers because they can do irreversible services. They can do simple extractions. They can do restorations. They can remove dental material to do restorations.
The thing that none of these groups can do outside of Alberta—Alberta is a bit of a special situation—is diagnosis. Only the dentist can provide the whole meal deal providing the restoration, doing the irreversible acts, and base the care on a diagnosis that has been done of the patient.
That's really where you have the difficulty moving from one scope to the other.
In order to be able to do reversible acts you have to have a certain type of training. In order to do the diagnostic you have a certain type of training that is based on a lot of fundamental basic science courses that are not necessarily provided to the other occupations. That's where the transfer becomes difficult. There is no doubt that the hygienist who goes back to dental school, gets a lot of credits, and can go through dental school easily because they have some of the work that was done before, but they still need to learn all of those additional skills.