California Code, Business and Professions Code - BPC § 1940

(a) A licensee who desires an inactive license shall submit an application to the dental hygiene board on a form provided by the dental hygiene board.

(b) In order to restore an inactive license to active status, the licensee shall submit an application to the dental hygiene board on a form provided by the dental hygiene board, accompanied by evidence that the licensee has completed the required number of hours of approved continuing education in compliance with this article within the last two years preceding the date of the application.

(c) The holder of an inactive license shall continue to pay to the dental hygiene board the required biennial renewal fee.

(d) Within 30 days of receiving a request either to restore an inactive license or to inactivate a license, the dental hygiene board shall inform the applicant in writing whether the application is complete and accepted for filing or is deficient and, if so, the specific information required to complete the application.