Professionally applied sealants, which are plastic films that coat and serve as a protective barrier for the chewing surfaces of the teeth, help to prevent cavities in the deep pits and fissures of teeth, where tooth brushing and fluoride are less effective (DHHS, 2000b). According to the National Health and Nutrition Examination Survey III (NHANES III), a nationally representative survey of the U.S. population in 1988-1994, 27.3% of 5- to 17-year-olds without sealants had untreated tooth decay, compared with just 11.1% of those with sealants (Nowjack-Raymer, Drury, & Selwitz, 1996). Interestingly, results from this survey further suggest that the socioeconomic disparity in untreated caries is striking among children and adolescents without sealants, but nearly nonexistent among children and adolescents with sealants (Nowjack-Raymer, et al., 1996). However, children and adolescents of low socioeconomic status are much less likely to have sealants than are their higher-income peers (Stack, Selwitz, & Drury, 1996).

As for professional preventive care, in 1997, about 64% of poor adolescents and 80% of near-poor and non-poor adolescents, nationally, reported having visited the dentist in the past year (MacKay, et al., 2000). During 1988-1994, sealants were in place for about one-quarter of children and adolescents in families with an annual income of $30,000 dollars or more and about 9 percent of children and adolescents in families with an annual income of $15,000 or less (Stack, et al., 1996).

Socioeconomic and insurance status may also affect utilization of preventive care. As noted above, poor adolescents are less likely than are near-poor and non-poor adolescents to visit the dentist (Chen, 1986; MacKay, et al., 2000) and to have dental sealants in place (Stack, et al., 1996). Moreover, low-income adolescents, especially those living near poverty, are less likely to have dental insurance (51%) than are either their higher-income peers (65%) or those living below the poverty level (60%; MacKay, et al., 2000). Children and adolescents without dental insurance are three times more likely to have unmet dental needs than are children with insurance, public or private (DHHS, 2000b). However, it is important to note that, according to one recent study of much younger children (Ismail & Sohn, 2001), access alone does not appear to account for the socioeconomic disparity in dental disease burden. This study surveyed first-grade children in Nova Scotia, Canada, where all children are covered by one insurance program that provides basic preventive, restorative, and surgical services (Ismail & Sohn, 2001). Despite this universal 'access' to professional dental care, children whose parents had low educational attainment had more cavitated teeth than did children whose parents had completed higher levels of education. This suggests that other factors-perhaps dental hygiene behaviors and/or dietary composition-also shape the socioeconomic disparities in dental health. Future research should attempt to elucidate the reasons behind this socioeconomic disparity, focusing on adolescents as well as on younger children.