Effect of Light Cure Methods for Intermediate Adhesive Layer on Microleakage of Sealants. An in Vitro Study

Background: The objective of this study was to determine the effect of an adhesive layer and its photopolymerization on the microleakage of sealants. Study design: 0.5mm-deep standardized fissurectomies were performed on extracted molars (n = 72). Teeth were randomly assigned to 3 different sealant materials (n = 24/group). Teeth were further divided to receive sealants with or without an adhesive layer. Each sealant with adhesive was also divided into two groups: adhesive was light-cured separately or light cured together with the sealant. Following thermocycling, microleakage was assessed using dye penetration and image analysis. Data was analyzed using ANOVA and Tukey's studentized ranged HSD tests. Results: Microleakage was not affected by type of sealant material (p>0.05) but was significantly influenced by application (p<0.05). Overall, placement of sealants without adhesive displayed greater microleakage than sealants with uncured adhesive (p<0.05). Within individual sealant types, this difference was only significant for Ultraseal XT (p<0.05). Sealants bonded with and without prior light curing did not show a significant difference in levels of leakage (Tukey's Studentized Range Test, p>0.05). Conclusion: An adhesive layer should be placed beneath sealants, but whether it should be light cured or left uncured before sealant placement varies by the sealant type.