As teeth develop, deep grooves called fissures naturally occur and where these grooves cross it is called pits. These areas account for more than 50% of cavities among children. In our office we clean the decalcified area of the teeth with air abrasion and/or a fissurotomy bur. Dental sealant is then applied to the teeth and flows into the pits and fissures. It is a plastic tooth coloured material that creates an impenetrable barrier to bacteria and decay, thus preventing cavities.