In order to practice in Ontario, a Dental Hygienist must complete and obtain a Diploma from a recognized dental hygiene program from a college or university. Once the program is completed, every dental hygiene graduate must then pass the National Dental Hygiene Board exam and become registered with the College of Dental Hygienists of Ontario (CDHO). Dental hygienists who operate their own dental hygiene practice must apply and receive special authorization to become self-initiated from the CDHO.