In Vitro Study On The Micro-tensile Bond Strength Of Four One-bottle Self-etching Adhesives

Objective Th e purpose of the present study was to investigate the enamel/dentin micro-tensile bond strength of four one-bottle self-etching adhesives to dentin and enamel in order to guide a suitable selection of adhesive material in clinical treatment, as well as to provide a basis for further improvement of self-etching adhesives.Materials and methods Twenty-four non-carious and non-discolored human premolars stored in 50%alcohol solution at 4℃were used in this study.The buccal enamel surfaces of the teeth were wet ground flat to obtain a 5.0*3.5mm² enamel flat surfaces using a series of SiC paper,ending with 600-grit SiC paper.The buccal surfaces were wet ground until a exposure of a 5.0*3.5mm² dentin flat surface occurred. Four adhesives were applied to the enamel or dentin surfaces(three teeth in a group) according to manufacturers' instructions,and the respective composite resins were placed on the adhesive-pretreated enamel or dentin surfaces with two 2-mm increments. All light-curing was performed by a light-curing machine with a power output of 800 m W/cm².After 24-h water storage at the room temperature,the teeth were then sectioned into sticks with a cross-sectional area of 1*1 mm² using a slow-speed diamond saw(Isomet^TM,Buhel er Ltd,USA) under water cooling.The micro-tensile bond strengths(μTBS) were performed with a micro-tensile testing device(Bisco,USA) at a tensile speed of 1 mm/mm.TheμTBS was calculated in MPa after measuring the exact cross-sectional area of each fractured beam with a vernier calliper.TheμTBS was thought to be 0 MPa when the specimens were fractured during sectioning or any other time before actual testing(pre-testing failures).Statistical analysis was carried out using the SPSS software package(SPSS,16.0 for Windows).One-way analysis of variance (ANOVA) was used to determine statistical differences inμTBS between the groups at theα=0.05 level of significance.Result One-way ANOVA analysis of the data revealed that micro-tensile bond strength of iBond to dentin was significantly lower than that of Clearfil S³ Bond and Xeno V(p＜0.05);however,there was no significant difference of dentinbond strength among the adhesives of Clearfil S3 Bond,Xeno V and G-Bond(p＞0.05).However, iBond achieved the highest enamel micro-tensile bond strength among four self-etching adhesives.Moreover,the micro-tensile bond strength value of Xeno V was significantly higher than that of Clearfil S3 Bond and G-Bond(p＜0.05).There were no significantly difference between the enamelμTBS and the dentinμTBS with exception of iBond. The enamelμTBS of iBond was significantly higher than the dentinμTBS.Conclusion The enamelμTBS of iBond was significantly higher than the dentinμTBS.There was no significant difference between the enamelμTBS and dentinμTBS of adhesives of Clearfil S3 Bond,Xeno V and G-Bond.