Protective effect of pit and fissure sealants on demineralization of adjacent enamel.

PURPOSE: This study's purpose was to evaluate the in vitro effect of sealants in protecting adjacent enamel from acid demineralization. METHODS: Occlusal fissures of extracted molars (N=10) were sealed with: conventional nonfluoride (DO; Delton Opaque) resin-based sealant (RBS); fluoride-containing RBS (US; UltraSeal XT plus, and CP; Clinpro); amorphous calcium phosphate-containing RBS (BW; Bosworth Aegis); or glass ionomer sealant (FT; Fuji Triage). The specimens were immersed in lactic acid gel for 20 days to create demineralized lesions on the occlusal enamel. Cross-sectional microhardness was measured at the lesion 0.5 mm from the sealant margin. Mineral loss (ΔZ, volume % mineral x μm) was calculated from the microhardness values and subjected to analysis of variance and student-Newman-Keuls tests. RESULTS: Mineral loss values (mean ±SD) were: 1,975 ± 806, 1,802 ± 512, 1,004 ± 421, 1,275 ± 375, and 88 ± 124 for DO, US, CP, BW, and FT, respectively; ΔZ for DO and US was significantly higher, and ΔZ for FT was significantly lower than that for CP and BW (P=.05). CONCLUSIONS: Resin-based sealants containing fluoride or amorphous calcium phosphate may provide some protective effect on demineralization of adjacent enamel vs conventional nonfluoride sealant. Glass ionomer sealant was the most effective in protecting adjacent enamel from acid demineralization.