It shall be unlawful for any dentist to practice his profession in a commercial or mercantile establishment, or to advertise, either in person or through any commercial or mercantile establishment, that he is a licensed practitioner and is practicing or will practice dentistry in such commercial or mercantile establishment. This section shall not prohibit the rendering of professional services to the officers and employees of any person, firm or corporation by a dentist, whether or not the compensation for such service is paid by the officers and employees, or by the employer, or jointly by all or any of them. Any dentist who violates any of the provisions of this section shall be guilty of a Class 1 misdemeanor. For the purposes of this section, the term “commercial or mercantile establishment” means a business enterprise engaged in the selling of commodities or services unrelated to the practice of dentistry or the other healing arts.