A Registered Dental Hygienist is a licensed dental professional who specializes in preventive oral health, typically focusing on techniques in oral hygiene. Dental hygienists provide three types of services to their patients. The first of these is preventive services to promote and maintain good oral health. The second is educational services to help patients develop behaviours that promote better oral heath and help them understand the importance of practicing these behaviours. The third type of service provided is therapeutic services which are treatments meant to stop disease and maintain healthy tissues in the mouth. Local dental regulations determine the scope of practice of dental hygienists. In most jurisdictions, hygienists work for a dentist, and some are licensed to administer local anesthesia. Common procedures performed by hygienists include cleanings known as prophylaxis, scaling and root planing for patients with periodontal disease, taking of prescribed radio graphs, dental sealants, administration of fluoride, and providing instructions for proper oral hygiene and care.