Tooth decay is a progressive oral disease resulting in the interaction of bacteria that naturally occur on the teeth and sugars in our diet. When sugar reacts with bacteria it causes a production of acids that break down the mineral in teeth, forming a cavity. Dentists remove the decay and fill the tooth, restoring the tooth to a healthy state. Severe decay can cause nerve damage resulting in the need for a root canal and crown. Avoiding unnecessary decay simply requires strict adherence to a dental hygiene regimen: brushing twice a day, flossing once a day, regular dental checkups, controlling the sugar in your diet and fluoride treatment. Practicing good oral hygiene avoids unhealthy teeth and costly treatment.