Objectives: This study is evaluate in vitro the influence of chlorhexidine, contained in the acid phosphoric or applied after the acid conditioning, in the resistance of union of a adhesive total etching system to the teeth after degradation of the adhesive interface. For that an area circulate of 3mm of diameter will be delimited in 180 fragments of coronary dentine of human molars recently extracted, and these will be divided at random in 3 groups, according to the treatment of the dentine surface previously the application of the adhesive: G1 - acid phosphoric 37%; G2 - acid phosphoric 37% with chlorhexidine; and, G3 - acid phosphoric 37% + chlorhexidine 2%. After the procedures each group will be divided into 4 subgroups according to the time thermocycling (TC) and water storage (WS): A - Without TC/24 h of water storage; B - 500 TC / 1 week of water storage; C - 2000 TC / 1 month of water storage; and, 12000 TC / 6 months of water storage. Following, the specimens will be carried out the shear bond strength tests. The results obtained will be analyzed and interpreted as regards the adhesive resistance of the treatment in question, as well as the times of degradation to that the groups were submitted.
News published in Agência FAPESP Newsletter about the scholarship: