The director may disapprove a contract or certificate form for dental service under a prepaid dental service plan if the director finds that the form:

(1) Is unfair, unfairly discriminatory, misleading, or encourages misrepresentation or misunderstanding of the contract;

(2) Provides coverage or benefits or contains other provisions that would endanger the solvency of such plan;

(3) Provides payment rates which are excessive, inadequate, or unfairly discriminatory; or

(4) Is contrary to law.