Objective: To compare the adhesive strength in dentin of three universal adhesive systems in vitro by means of the shear test. Materials and methods: Seventy-five bovine teeth were selected and cut. Dentin was exposed from the buccal surface of the crowns with 220 grit sandpaper, and samples were then inserted in transparent acrylic bases (15x10mm). The samples were randomly divided in 3 groups (n=25): G1-Universal adhesive system Scotchbond™ Universal (3M ESPE-USA); G2-Universal adhesive system Peak Universal Bond (Ultradent); G3-Universal adhesive system Tetric N-Bond (Ivoclar Vivadent). The adhesive procedures were carried out according to the instructions of each manufacturer and the restorative procedures were carried out with micro-cylinders (made of Tygon type tubing 0.79x1.5mm) of the composite resin Filtek™ Z350XT-A2 (3M ESPE-USA). The samples were incubated at 37ºC (+/-5ºC) for 24 hours. Adhesive strength was evaluated in a universal test machine by means of the shear test (0.5mm/ min, 500N) and the resulting fracture type was evaluated with a Dinolite digital microscope (x200). The results were analyzed by descriptive statistics (Mean±SD), and inferential statistics by a one-way ANOVA. Results: No statistically significant differences were found between the universal adhesive systems evaluated G1 (14.91±4.76), G2 (16.90±4.11) and G3 (17.34±4.04)/(p=0.114). Conclusions: The shear test resulted in similar values of immediate adhesive strength of the three universal adhesive systems used.

Objetivo: El propósito de este estudio fue comparar la resistencia compresiva de 2 resinas tipo Bulk fill y 2 resinas convencionales. Materiales y métodos: 136 muestras cilíndricas (2mm y 4mm), divididos en 8 grupos (n=17); G1 SonicFill™ (4x2mm), G2 SonicFill™ (4x4mm), G3 Tetric® N-Ceram Bulk Fill (4x2mm), G4 Tetric® N-Ceram Bulk Fill (4x4mm), G5 Filtek™ Z250 XT (4X2mm), G6 Filtek™ Z250 XT (4x4mm), G7 Te-Econom Plus® (4x2mm) y G8 Te-Econom Plus® (4x4mm). La resistencia compresiva fue evaluada con la máquina Instron® a una velocidad de desplazamiento fijo de 1,0mm/min. Los test de ANOVA, Kruskall Wallis, t Student y U de Mann Whitney fueron empleados para el análisis estadístico. Resultados: para las resinas Bulk Fill, Tetric® N-Ceram Bulk Fill (310,06- 4x2mm, 303,87-4x4mm) mostró mayor resistencia compresiva que SonicFill™. Para las resinas convencionales, Filtek™ Z250 XT (295,9-4x2mm, 289,7-4x4mm) obtuvo mayor resistencia compresiva que Te-Econom Plus®. A la comparación de todos los grupos, Tetric® N-Ceram Bulk Fill presentó los valores compresivos más altos en ambos espesores 4x2mm(0,122) y 4x4mm(0,333), con diferencias estadísticas significativas (p<0,001*-4x2mm, p=0,004- 4x4mm). Conclusión: Tetric® N-Ceram Bulk Fill puede ser una buena opción para restauraciones posteriores, ya que su propiedad mecánica de resistencia compresiva es superior en relación con las otras evaluadas.