The effect of different thermocycle and water storage times on bonding of one step adhesive systems to dentin

The aim of this in vitro study is to determine the effect of differentthermocycle and water storage times on bonding of 4 all-in-one self etchadhesives to dentin (Optibond All-In-One, Clearfil Tri- S Bond, One Coat7.0, Xeno V).The buccal surfaces of teeth were ground with 100, 600, 1200 gritsilicon carbid papers under running water to obtain 2 mm dentinthickness. Each group having 49 samples, were formed under 4 maingroups. To perform the bonding materials to a spesific area withhomogeneity, an adhesive tape with 4 mm in diameter was sticked ontothe dentin surface. All of the materials used in the study were appliedon the dentin surface according to manufacturer?s instructions.Cylindrical translucent molds 4 mm in diameter and in height werepositioned over the bonded dentin and filled with Z250 composite resinin two layers and each layer were polimerized during 20 seconds. Thecomposite resin have A2 equivalent color code on the vita scale.Among all the bonded specimens, control group was kept in waterfor 24 hours at 37 C dessicator. For artificial aging experiment, all thesamples were thermo-cycled and stored in water as 6 sub-groups.Thermocylcus groups were thermo-cycled 500, 2000 and 4000 timesbetween 5 -55 C. Other specimens were stored in water at 37 Cdessicator for 1, 3 and 6 weeks. All of the experimental groups weresubjected of shear test.The statistical analysis of the results were performed by `one wayANOVA? and post hoc multiple comparison `TUKEY? tests.VIn conclusion, among all the groups which were thermo-cycled andimmersed in water, considering significant differences, a decrease inbonding strength was examined only in Clearfil Tri-S Bond. Clearfil Tri-S Bond and Xeno V presented a significant decrease in bondingstrength after 2000 and 4000 thermal cyclus. After all of the artificialaging experiments, only Clearfil Tri-S-Bond showed significantly lowerbonding strength than Optibond All-In-One after 6 weeks of waterstorage.Keywords: All-In-One systems, thermocyclus, water storage