Indiana Code Title 25. Professions and Occupations § 25-13-1-11

(1) uses the titles “Licensed Dental Hygienist”, “Dental Hygienist”, or the letters “L.D.H.”, “R.D.H.”, or “D.H.” in connection with his or her name;

(2) holds himself or herself out to the public in any manner that he or she can or will render services as a dental hygienist;

(3) removes calcific deposits or accretions from the surfaces of human teeth or cleans or polishes such teeth;

(4) applies and uses within the patient's mouth such antiseptic sprays, washes, or medicaments for the control or prevention of dental caries as his or her employer dentist may direct;

(5) treats gum disease;

(6) uses impressions and x-ray photographs for treatment purposes;  or

(7) administers local dental anesthetics or nitrous oxide, except for the administration of local dental anesthetics or nitrous oxide by: