Effect of sealants on laser fluorescence caries detection in primary teeth

The aim of this study was to investigate in vitro the effects of clear or opaque sealants, on the laser fluorescence readings for occlusal caries detection in primary molars. For this reason, 427 occlusal sites in 199 teeth were clinically examined by one dentist, and their laser fluorescence (LF) was measured locally with the DIAGNOdent™ device, both before and after the teeth had been sealed with Delton Clear LC or Delton Opaque LC. For 29 of these teeth, we also measured the laser fluorescence by scanning the fissures before and after sealant application. We used Wilcoxon's signed ranks sum test and Spearman's rho correlation to compare and correlate the LF readings before and after sealing, while we used the Mann-Whitney U test to compare the two materials. Finally, we used the Kruskal-Wallis test to compare readings taken locally with those taken by the scanning technique. The results showed that there was an LF increase by a mean of 6 units after sealing with the clear material, while there was a 15 units decrease after sealing with the opaque one. LF readings before and after sealing correlated better for the clear material (rho = 0.826) than for the opaque one (rho = 0.507). LF readings were statistically significantly affected by both clear and opaque sealants (P < 0.001). However, this effect was statistically significantly less pronounced for the clear material (P < 0.001). There was also no difference between the LF readings taken by the fissure scanning technique or locally (P > 0.05). In conclusion, LF readings for occlusal caries detection in primary molars were significantly affected by both the clear and the opaque materials. However, the effect for the opaque material was more pronounced.