The Chairside Instructor 11 How sealants are applied A sealant is a coating that protects a tooth from decay. It can also be used to help stop the progression of early signs of decay on the chewing surface of a tooth. When teeth are treated with sealants, they are less likely to get cavities. Sealants can be applied quickly and painlessly. Tooth surface before a sealant is applied. Tooth surface protected by a sealant. How sealants help prevent decay The chewing surfaces of a molar (magnified) have pits and grooves that trap plaque and bits of food. Even a toothbrush bristle is too big to reach inside a groove in the tooth (magnified). Tooth groove Toothbrush bristle Sealants Prevention and Diagnosis