California Code, Business and Professions Code - BPC § 1967.4

(a) The bylaws of a registered dental hygienist in alternative practice corporation shall include a provision whereby the capital stock of the professional corporation owned by a disqualified person, as defined in subdivision (e) of Section 13401 of the Corporations Code, or a deceased person, shall be sold to the professional corporation or to the remaining shareholders of the professional corporation not later than 90 days after disqualification, if the shareholder becomes a disqualified person, or not later than six months after death, if the shareholder becomes deceased.

(b) A registered dental hygienist in alternative practice corporation shall provide adequate security by insurance or otherwise for claims against it by its patients arising out of the rendering of professional services.