Cal. Bus. & Prof. Code § 1936
Except as otherwise provided in this article, an expired license may be renewed at any time within five years after its expiration by filing an application for renewal on a form prescribed by the dental hygiene board and payment of all accrued renewal and delinquency fees. If the license is renewed after its expiration, the licensee, as a condition precedent of renewal, shall also pay the delinquency fee prescribed by this article. Renewal under this section shall be effective on the date on which the application is filed, on the date on which the renewal fee is paid, or on the date on which the delinquency fee, if any, is paid, whichever last occurs. If so renewed, the license shall continue in effect until the expiration date provided in Section 1935 that next occurs after the effective date of the renewal.
Ca. Bus. and Prof'l. Code § 1936