Section 313-12-X - PRINCIPLES OF ETHICS AND CODES OF PROFESSIONAL CONDUCTA. Dentists shall comply with the American Dental Association Principles of Ethics and Code of Professional Conduct, as amended, February 2018.B. Dental hygienists shall comply with the American Dental Hygienists' Association Code of Ethics as published in its Bylaws and Code of Ethics, adopted June 13, 2016.C. Denturists shall comply with the National Denturist Association's Code of Conduct, Appendix A, as published in its By-Laws dated September 19, 2015.02-313 C.M.R. ch. 12, § X