It is estimated that 90% of adults in America have had a cavity at one time. A dental cavity, quite simply, is a hole in a tooth. Cavities result from tooth decay, which gradually erodes the tooth over time. Many people don’t realize, however, that this process of decay can actually be reversed, preventing cavities from forming. In order to understand how to stop and reverse the process of tooth decay, it is helpful to first understand that process.

The human mouth is full of hundreds of different types of bacteria, which live on all the surfaces in the mouth. Much of this oral bacteria is beneficial, but some, like the ones that contribute to tooth decay, are harmful. Certain types of harmful bacteria react with sugar to form acids, and these acids can gradually eat away at the tooth and cause a cavity. Every day, the harmful and beneficial bacteria and other elements in the mouth battle against one another. Dental plaque, which is a sticky bacterial film that forms on the teeth, combines with any food or drink that contains starch or sugar to create acids that eat away at tooth enamel and create cavities. The minerals in saliva combine with fluoride, which is found in most municipal tap water as well as in toothpaste and mouth rinses, to help the tooth enamel replace minerals and repair itself. This back-and-forth process occurs all day, every day; acid erodes minerals in enamel while saliva and fluoride replenish these minerals. If a tooth is exposed to too much acid, however, a cavity may begin to form. If you frequently eat or drink foods that are high in sugar and starches, this overproduction of acids can overwhelm the balance in the mouth and lead to tooth decay. An early sign of tooth decay often presents itself as a white spot on the tooth where excessive minerals have been depleted. At this point, tooth decay is still reversible; enamel can use minerals in saliva, combined with fluoride, to repair itself. As the tooth decay process progresses, however, more and more minerals are depleted from the tooth enamel. Eventually, enamel gradually weakens until it is destroyed, forming a cavity. Cavities cannot be reversed, but they can be repaired with dental fillings.

Fluoride is a mineral that helps prevent cavities from forming and also helps reverse tooth decay in its early stages. Fluoride protects the teeth by replacing lost minerals in tooth enamel and limiting the amount of acid that can be produced by bacteria. The majority of municipal water supplies in the United States use fluoridated water; if you have well water, which isn’t fluoridated, talk to your dentists about potential fluoride deficiency. People who consume primarily bottled water may also have a fluoride deficiency, so be sure to tell your dentist if you don’t regularly drink tap water from a municipal water supply. Dentists also recommend introducing fluoride to the mouth by using fluoridated toothpaste to brush twice daily. If your dentist determines that you would benefit from additional fluoride,  you may get an in-office fluoride treatment, prescription fluoride tablets, or a recommendation for a fluoridated mouth rinse. Diet is also important to cavity prevention. If you consume a diet that is high in sugars or starches, you may be upsetting the acid balance in your mouth and contributing to tooth decay. Maintaining a balanced diet, including plenty of fresh fruits and vegetables and lots of fresh water, can help fight off the acids that cause tooth decay. Limiting snacks and fruit juice and reducing the amount of sugar in the diet can help maintain the health of the mouth. It is especially important to brush your teeth before bedtime and not eat or drink anything sugary after doing so, as saliva production decreases during sleep and therefore leaves the mouth more susceptible to acid attacks.

Brushing your teeth twice a day, using a soft-bristled brush and fluoride toothpaste, and flossing once daily, is the first step toward preventing cavities. If you are a parent, make sure to teach your child proper brushing and flossing techniques. You may also want to talk to your dentist about dental sealants. Dental sealants are coatings that are painted onto the chewing surfaces of the teeth, providing a barrier to protect the teeth and prevent food from getting stuck in uneven chewing surfaces. Many dentists recommend sealing a child’s adult molars as soon as they erupt into the mouth, though it is never too late to seal surfaces of the teeth. Regular dental visits, including examinations and cleaning, can also help prevent tooth decay and fend off cavities.

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