We have previously discussed how criminal and tort charges apply in such cases of unauthorized practice of medicine or law (here). In torts, such individuals are subject to the standard of the profession, in this case the standard of what a reasonable dentist would have done in such a procedures. In criminal law, the standard is more straightforward. If you hold yourself out as a doctor or lawyer, you are committing a crime.
Schoengold fired Yzeiraj and she that he learned she was treating patients when he was out of the office. She is now charged with assault in the second and third degrees, unauthorized practice, attempted grand larceny and reckless endangerment.
What will be interesting is whether these patients will sue Schoengold for negligence in the monitoring of his office and employees.