The aim of this study was to define optimal power settings as well as curing time associated with evaluating the curing depth of a composite resin as a function of Vickers hardness. The tests were performed with a hybrid composite resin cured with a halogen lamp and argon ion laser, with different exposure times and power settings. The composite resin bulk technique was used using a black polypropylene matrix with thicknesses ranging from 1 to 4 mm and Vickers microhardness was measured on the opposite surface of the light activation. ANOVA and Tukey statistical tests were used. The results showed that the groups activated by the laser for 20 s, at 200 and 250 mW, did not present statistically significant differences regarding the halogen lamp with 1 mm thickness, but the halogen lamp showed better results with thickness values more than 2 mm (p < 0.05).

The hardness is a mechanical property utilized to compare restorative materials such as biological tissue and can be defined as the resistance of material for a permanent impression and a number related to the applied force and the surface area. As each material has its own mechanical characteristic, for this study utilized two materials: amalgam and composite resin and two dental tissues: bovine dentin and enamel. In total were 20 specimes, divided among 4 groups: A, R, D, E equivalent for each superficial. The groups A and R received cavities preparation that were restored into with the respective materials, the group D had the superficial wore until exposure of the dentin and the group E was so planning. For the microhardness testing were utilized Vickers and Knoop indenter; loads of 25, 50 and 100gf in 5 time of application 5, 15, 30, 45 e 60 seconds. The values were submitted for statistical analysis by Kruskall-Wallis and Student-Newman-Keus tests (p<0.05). Due to the results, it is concluded that the amalgam presented a minimum load adequated of 50gf and a time of application of 30 seconds as the Vickers as Knoop. In the composite resin the minimum load was 50gf and time was 45s for Knoop, the Vickers didn't have statistical diference. In dentin the minimum load was 50gf for all studies times for two tests. And the enamel presented the minimum load adequated was 100gf for all the times in the Knoop microhardness, the Vickers test didn't have statistical diference.