Dental hygienists are the people in a dentist's office who perform your dental cleanings every six months. They can take x-rays of patients' mouths and can apply fluoride treatment or dental sealant to your teeth. They're trained in oral health education and are also trained to identify signs of oral diseases, as well as any other potential dental problems, so they can report any concerns to your dentist. They may also assist the dentist during dental procedures.