Purpose: To evaluate, in the laboratory, five light-cured pit and fissure sealants (ClinPro Sealant, Grandio Seal, Delton Seal-N-Go Illuminating, Embrace WetBond, Delton LC) and a filled bonding resin (Optibond FL Adhesive) used as a sealant in respect to their marginal adaptation before and after simultaneous thermal cycling and occlusal loading and their seal and failure cracks after loading.
Methods: 60 caries-free upper molars were mechanically and thermally loaded after sealant application. Marginal adaptation was evaluated in the SEM before and after loading and a dye penetration test was performed after loading. In addition, micro-morphology of the occlusal contact area was qualitatively assessed.
Results: Percentages of "continuous margin" ranged from 97.5 to 72.3% before, and from 92.2 to 56.6% after loading. Loading significantly influenced marginal quality (ANOVA, P < 0.05). Dye penetration after loading ranged from 0.05 to 1.21, with significant differences between groups (Kruskal-Wallis, P < 0.05). Different degrees of disintegration were observed in the occlusal contact area of all materials after loading.