Cal. Business and Professions Code § 1952

It is unprofessional conduct for a person licensed under this article to do any of the following: (a) Obtain or possess in violation of law, or except as directed by a licensed physician and surgeon, dentist, or podiatrist, a controlled substance, as defined in Division 10 (commencing with Section 11000) of the Health and Safety Code, or any dangerous drug as defined in Section 4022. (b) Use a controlled substance, as defined in Division 10 (commencing with Section 11000) of the Health and Safety Code, or a dangerous drug as defined in Section 4022, or alcoholic beverages or other intoxicating substances, to an extent or in a manner dangerous or injurious to themselves, to any person, or the public to the extent that the use impairs the licensee’s ability to conduct with safety to the public the practice authorized by their license. (c) Be convicted of a charge of violating any federal statute or rules, or any statute or rule of this state, regulating controlled substances, as defined in Division 10 (commencing with Section 11000) of the Health and Safety Code, or any dangerous drug, as defined in Section 4022, or be convicted of more than one misdemeanor, or any felony, involving the use or consumption of alcohol or drugs, if the conviction is substantially related to the practice authorized by their license. (1) The record of conviction or a copy certified by the clerk of the court or by the judge in whose court the conviction is had, shall be conclusive evidence of a violation of this section. A plea or verdict of guilty or a conviction following a plea of nolo contendere is deemed to be a conviction within the meaning of this section. (2) The dental hygiene board may order the license suspended or revoked, or may decline to issue a license, when the time for appeal has elapsed or the judgment of conviction has been affirmed on appeal, or when an order granting probation is made suspending imposition of sentence, irrespective of a subsequent order under any provision of the Penal Code, including, but not limited to, Section 1203.4 of the Penal Code, allowing a person to withdraw a plea of guilty and to enter a plea of not guilty, or setting aside the verdict of guilty, or dismissing the accusation, information, or indictment.