The American Dental Association recommends brushing your teeth twice a day and flossing at least once a day. But that is only part of maintaining good oral health. Brushing and flossing won’t remove dental plaque that builds up and hardens on your teeth and infects your gums. Only a trained hygienist has the skills and equipment to do that, which is why you need to visit the dentist for cleanings and exams about twice a year.