There shall be a board of registration in dentistry, called the board in sections 19 to 21, inclusive. The board shall consist of 11 persons, each of whom shall be a legal resident of the commonwealth, to be appointed by the governor; 6 shall be graduates of a reputable dental college and be reputable dentists who have maintained a license to practice dentistry in the commonwealth for the 8 years preceding the appointment; 2 shall be graduates of a reputable school of dental hygiene and be reputable dental hygienists who have maintained a license to practice dental hygiene in the commonwealth for the 5 years preceding the appointment; 1 of whom shall be a dental assistant in the commonwealth for the 5 years preceding the appointment; and 2 shall be representatives of the public, subject to section 9B. No more than 1 member of the board who is a dentist may be a full-time member of the faculty or a trustee of an institution engaged in educating dentists or having power to confer degrees in dentistry. Board members shall serve for a term of 5 years. In April, the governor shall annually appoint a successor to those members of the board whose terms are expiring in that year. No member shall serve more than 2 full terms.