(a) The rates charged by a dental service plan corporation to the subscribers for dental services shall at all times be subject to the approval of the department.
(b) Every contract between a dental service plan corporation and a dentist, whereby the plan provides for payment of a fee or fees to the dentist for dental services rendered by the dentist to subscribers, shall contain a clause stating that the dental service plan corporation shall be liable for such fee or fees rather than the subscribers receiving said dental services. Such contract shall also contain a clause whereby, upon termination of the contract by either party or upon expiration thereof, a dentist is obligated to complete any procedure which he has undertaken upon any subscriber.