Sealing of occlusal hidden caries lesions: an alternative for curative treatment?

The bacterial composition of the dentine of thirty molars with sealed occlusal surfaces (Delton tinted) was examined. Undiagnosed hidden caries was present at the time of treatment. Although clinically assessed as good (age 3.4 years, s.d. 2.1), 47 percent of the sealants had a marginal defect, when assessed with SEM. The dentine of the treated teeth was of a soft consistency. The median of the number of microorganisms was 400 (range 0-3.10(5)) cfu per sample. Mutans streptococci and lactobacilli were found in 53 percent of the samples. No relationship was found between the number of microorganisms and the marginal adaptation of the sealant, when examined under SEM; neither was a relationship found between the age of the sealant and the number of microorganisms (Kendall's Tau-C = 0.17, n.s. and -0.01, n.s., respectively). At present, there are insufficient grounds for treating nonvisible lesions (with a radiolucency on the bitewing) with a resin sealant.