A dental hygienist is a licensed dental professional who is registered with a dental association or regulatory body within their country of practice.They are a primary healthcare professional who works independent of, or alongside dentists and other dental professionals in a team to provide full oral health care.ental hygienists in the United States must be graduates from a dental hygiene program, with either an associate degree (most common), a certificate, a bachelor's degree or a master's degree from a dental hygienist school that is accredited by the American Dental Association (ADA).