Influence of lubrication or cleaning on the microhardness of composite

Objective: The aim of this study was to assess the microhardness of a composite resin lubricated/cleaned with different agents. Method: A metal mold was used to build cylindrical specimens (2mm high and 5 mm in diameter). The composite resin used was Filtek Z350 XT (3M ESPE) color A2.The composite resin was placed in bulk increment. Each of the four groups (n = 8) was lubricated/cleaned with different agents during insertion of the composite: G1-Cleaning with alcohol 96 °, G2-lubrication alcohol 96 °, G3 -Lubrication Adper^TM adhesive Single Bond 2 (3M ESPE) and G4-without lubricated/cleaned(control). A MMT Vickers microhardness tester Buehler (Lake Bluff, Illinois, USA) was used with a load of 100gf for 30s. Four indentations were made on the top and bottom surfaces of each sample. Result: ANOVA and Tukey tests were used to detect significant differences between the groups. There were no statistically significant differences among the groups (p> 0.05) analyzed bottom surfaces. The top surface of the specimens lubricated with adhesive presented significantly lower values of microhardness (p <0.05). Conclusion: Lubrication with adhesive presented a decrease in the top surface microhardness of the composite resin.