California Code, Business and Professions Code - BPC § 1926.4

When a registered dental hygienist in alternative practice desires to have more than one place of practice, the person shall, before opening the additional office, apply to the dental hygiene board, pay the fee required by Section 1944, and obtain permission in writing from the dental hygiene board to have the additional place of practice, subject to a biennial renewal fee described in Section 1944.