Dental sealants are thin plastic coatings applied to the chewing surfaces of back teeth. While fluoride has played a large role in decreasing smooth surface decay, fluoride has its least preventive effect on the deep grooves, called pits and fissures, of the back teeth. Dental sealants have been shown to be highly effective in the prevention of pit and fissure caries. Data from 1988 to 1991 in the National Health and Nutrition Examination Survey (NHANES III) revealed that while tooth surfaces with pit and fissures accounted for 15 percent of all tooth surfaces, they were the sites of at least 83 percent of the tooth decay in children.
Dental sealants evolved from a technique called enamel bonding that was first reported in the mid-1950s. Dental sealants were introduced in 1967 and their effectiveness was recognized by the American Dental Association in 1971. Current sealant materials are either chemically activated or light polymerized and come in various colors, including clear, white, yellow, green, and pink.
The decision to place sealants is usually based on the patient's disease risk factors, presence of disease, and the morphology of the pits and fissures. Teeth with the highest priorities for sealant placement are usually the first and second permanent molars. Because of their less shallow grooves, primary or baby molars and permanent bicuspids are less susceptible to decay and therefore are at a lower priority for placement.
Although the application process is fairly simple, attention to technique is very important. Inadequate isolation and subsequent contamination by water or saliva will cause the sealant to fail. The teeth to be sealed are first isolated by use of rubber dental dams or cotton rolls. The teeth are then cleaned by rotary instruments, brushing, or wiping the surface with cotton. A mild acidic solution is then applied to the grooves and washed off after approximately twenty seconds. The teeth are then thoroughly dried. The resultant tooth surface has been etched or roughened, allowing the sealant material to adhere to this roughened surface. For continued effectiveness, the sealants should be checked regularly as part of periodic recall visits and replaced as needed.
A sealant is virtually 100 percent effective if fully retained on the tooth. Various studies have shown chemically activated sealants to remain intact 92 to 96 percent of the time after one year, 67 to 82 percent after five years. Other long-term studies have shown retention to be approximately 41 to 57 percent after ten years and 28 to 35 percent after fifteen years. Results for chemically activated sealants versus light polymerized sealants were found to be the same after five years. Pooled results from seventeen studies found that sealants reduced caries over 70 percent.
In 1990, the United States Public Health Service published a health objective for the year 2000, stating that 50 percent of children should have one or more sealants on permanent teeth. NHANES
DAVID E. HEISEL
American Dental Association Council on Access, Prevention and Interprofessional Relations and Council on Scientific Affairs (1997). "Dental Sealants." Journal of American Dental Association 128:485–488.
Proceedings of the Workshop on Guidelines for Sealant Use (1995). (Sponsored in part by School of Public Health, SUNY, Albany.) Journal of Public Health Dentistry 55(5).
Siegal, Farquhar C., and Bouchard, J. (1997). "Dental Sealants: Who Needs Them?" Journal of U.S. Public Health Service 112(2):98–106.
U.S. Department of Health and Human Services (2000). Oral Health in America: A Report of the Surgeon General. Washington, DC: Author.