Dental sealants act as a barrier, protecting the teeth against decay-causing bacteria. The sealants are usually applied to the chewing surfaces of the back teeth (premolars and molars) where decay occurs most often. In children, these sealants are often applied soon after the permanent molar teeth have grown into position in the mouth. They will occasionally need to be replaced if they become worn or come off. In adults, sealants may be recommended if a patient is at higher risk for decay due to a variety of factors. In older adults, sealants may be helpful to assist in preventing decay while experiencing “dry mouth”, a condition in which there is not enough saliva produced in the mouth to adequately control the bacteria that lead to cavities.