Sealants can be used to protect the decay-prone areas of the back teeth, and are possibly the best preventive care measures that we can provide. Studies show that sealants can reduce caries in these teeth by 70%. If a teenager has never had decay, we may not suggest sealing his teeth – particularly if he brushes and flosses well and has a healthy diet. However, if a teenager has had a history of cavities, it may be a reasonable recommendation. Sealing can be an effective preventive measure, but should be considered on a case-by-case basis.