Relative caries experience of sealed versus unsealed permanent posterior teeth: a three-year study.

A clinical trial has investigated the occlusal caries experience of permanent molars and premolars, following the apparent loss of occlusal sealants applied by dental students, in comparison with that of unsealed teeth erupted for time periods similar to the sealant evaluation periods. Complete retention at one, two and three years was relatively poor. Throughout the study, premolars were superior to molars in fully retaining sealants. Regardless of the clinical condition of the sealant, a statistically significant reduction in occlusal caries-experience of sealed teeth was seen in comparison with control teeth. This relative reduction was highest at one year: 72 percent for molars and 83 percent for premolars, dropping at three years to 23 percent for molars and 64 percent for premolars. At one year, molar sealant failures showed a statistically significant, relative reduction of 41 percent in occlusal caries-experience over control teeth, suggesting as ongoing caries-inhibitory effect. Thereafter, the history of a failed sealant neither enhanced nor reduced the occlusal caries susceptibility of molars, and premolars over that of control teeth.