It is unlawful for any person except a dental service plan corporation, incorporated in accordance with this chapter, and operating in accordance with authority from the commissioner, or a nonprofit corporation organized under chapter 27, 28 or 29 of this title, or an insurance company properly qualified in this state to write accident, health or disability insurance, to establish, maintain, or operate a dental service plan, or to solicit subscribers to or enter into contracts with respect to a dental service plan. This prohibition, however, shall not be construed as preventing a person from furnishing dental services for the prevention of diseases among the person's employees or from furnishing dental services required under the Workers' Compensation Law, compiled in title 50, chapter 6, and related legislation when the employee is not charged for the services. The prohibition in this section shall not apply to persons engaging in transactions in this state involving a master group subscription contract lawfully issued and delivered in another state, and the persons shall not be subject to this chapter or otherwise regulated by or prohibited from engaging in the transactions solely as a result of the transactions.