Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Purpose: To evaluate the in vitro marginal adaptation (gap formation) in the fissure of different sealer materials (resin sealant, glass-ionomer cement, resin-modified glass-ionomer cement, and adhesive system) submitted to thermal and chemical stress, using scanning electron microscopy evaluation (SEM). Methods: 80 impacted human third molars were randomly assigned to the following experimental groups (n=10): FluroShield (F), Helioseal Clear Chroma (H), Vitremer (V), Fuji II-LC (FII), Ketac-Molar (KM), Fuji IX (FIX), Single Bond (SB), and Clearfil Protect Bond (CF). All groups were subjected to thermocycling and 14 days of pH cycling. A blinded and calibrated examiner performed SEM analysis. Gap formation was scored according to: 0= no sealant marginal gaps; 1= sealant marginal gaps present or total sealant loss. The score 0 was considered a success, while score 1 represented failure. Data were analyzed by Kruskal-Wallis and Bonferroni tests (P< 0.05). Results: The success rates of SB (100%) and V (90%) were similar, but statistically superior to F (30%), H (20%), FIX (20%0), and CF (0%) (P< 0.05). A tendency for similar behaviors of FII and KM to SB and V was observed and for similar behaviors of F, FIX and H to CF. The worst results were obtained for CF. (Am J Dent 2008;21:377-382).216377382Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES
