ResumoA adequada fotopolimerização das resinas compostas é fundamental para obtenção de uma boa dureza capaz de resistir aos esforços mastigatórios. Assim, o objetivo deste estudo foi avaliar a influência das técnicas de fotopolimerização -Convencional (CONV), Soft-start (SS) e Pulso atrasado (PA) na microdureza Knoop de três resinas compostas. Para a confecção dos corpos-de-prova foram utilizadas as resinas compostas Filtek Z350 (3M ESPE), Empress Direct (IvoclarVivadent) e P90 (3M ESPE). Foram obtidos nove grupos experimentais em função da técnica de polimerização e resina composta. Vinte e quatro horas após a fotopolimerização foi realizado o teste de microdureza Knoop nas superfícies de base e topo de cada corpo-de-prova. Assim, os valores obtidos foram submetidos ao teste de Kruskall Wallis, seguido do teste de Dunn, p < 0,05. A eficácia da polimerização na superfície de topo das resinas compostas testadas não foi afetada pelos diferentes modos de polimerização. A resina composta Empress Direct apresentou os mais baixos valores de dureza para todos os modos de polimerização quando comparada às demais resinas compostas avaliadas. Palavras-chave: fotopolimerização, dureza knoop, resina composta. AbstractProper curing of composites is critical to obtaining good toughness able to withstand masticatory forces. The objective of this study was to evaluate the influence of curing techniques -conventional (CONV), Soft -start (SS) and Pulse delayed (PA) in microhardness of three composites. To make up the body-of -evidence were used composites Filtek Z350 (3M ESPE), Empress Direct (IvoclarVivadent) and P90 (3M ESPE). Nine experimental groups were obtained according to the polymerization technique and composite resin. Twenty -four hours after curing was performed Knoop microhardness test surfaces of base and top of each body -of -evidence. Thus, the values obtained were subjected to the Kruskal Wallis test followed by Dunn's test, p < 0.05. The effectiveness of the polymerization on the top surface of the composites tested was not affected by different modes of polymerization. The Empress Direct composite resin showed the lowest hardness values for all modes of polymerization compared to other composites evaluated.

Introduction Adhesive technology has been developed quickly since its introduction about fifty years ago. Its goal is to produce a close contact within enamel and dentin. Failures in this process could result in microleakage, and allow the infiltration of bacteria, fluids and ions. Recent studies have been shown the use of chlorhexidine associated with adhesive systems can be able to inhibit the bacteria action. Objective The aim of this study was to evaluate the addiction of different percentages of chlorhexidine to a self-etch adhesive. Methodology The solution of digluconatechlorhexidine was increased to the primer of the two pass self etch adhesive to create a 0.5%, 1.0% and 2.0% chlorhexidine primer solution and after they were distributed in four groups (G1, G2, G3 and G4). Saliva samples (N=10) were used to test bacteria activity. Result They were spread in a blood medium with filter paper disks containing the different treatments. After the incubation, the inhibitions halos formation were evaluated. Conclusion This study demonstrated that, in vitro, the addition of different percentages of chlorhexidine digluconate to the self-etch adhesive induced inhibited halos at bacteria of saliva samples, independent from their concentration.