Over 50 years ago, studies of people entering the military revealed that Americans' teeth were in pretty poor shape. Few people took good care of their teeth. There were no guidelines for how often you should visit a dentist. Many dentists concentrated on fixing problems rather than preventing them.
Dental and health organizations concluded there was a need to establish standards for preventive dentistry. They didn't have enough evidence, so they made a "best guess" recommendation. They said people should go to their dentist twice a year for checkups and cleaning because cavities and gum disease are preventable. Some say the original use of the twice-a-year advice actually developed from Pepsodent toothpaste ads.
Whatever the origins, this has demonstrated to be a useful rule of thumb for many people. But scheduling dental appointments really should be based upon each person's oral hygiene, habits and medical conditions.
Even if you take exceptional care of your teeth and gums at home, you still must see a dentist regularly. Your dentist can examine for problems that you may not see or feel. Many dental problems don't become evident or cause pain until they are in a more advanced stage. Examples include cavities, gum disease and oral cancer. Regular visits enable your dentist to find early signs of disease. Problems can be treated/fixed at a manageable stage.
On average, seeing a dentist twice a year works fine for many people. Some can get away with fewer visits. Others may find they need more frequent visits. People with very little risk of cavities or gum disease can do fine visiting their dentist just once per year. People with a high risk of dental disease might require them to visit every three or four months, or more. This high-risk group includes:
People with current gum disease
People with a weak immune response to bacterial infection
People who tend to get cavities and/or build up plaque
The schedule for any person can change during a lifetime. In times of stress or illness, you may need to see the dentist more frequently than usual. The dentist could help you to fight off a temporary infection or treat changes in your mouth.
If you take great care of your teeth and gums at home and your dentist doesn't find any cavities or gum disease for a few years, he or she may decide to lengthen the time between visits. Ask your dentist for the optimal schedule for your routine dental visits.