Comparative Study Of Three Kinds Of Self-etching Adhesives In Terms Of Their Bonding Strength And Bonding Durability With Dentin

Part one Comparative study on the instant bonding strength of the three kinds of self-etching adhesivesObjectiveBy comparing the three kinds of self-etching adhesives in terms of their instant bonding strength and the fracture type which was observed by the microscope,we would like to find out the different bonding performances among the three self-etching adhesives.The three kinds of self-etching adhesives including the new universal bonding system which is called the eighth-generation adhesive,the classical sixth-generation two-step bonding system,and the seventh-generation one-step bonding system.This research analyze the bonding properties of the new universal adhesive Single bondTM Universal(3M company,USA)qualitatively and quantitatively,aiming to provide reference data for clinical application.Methods24 freshly extracted,caries-free human third molars were selected and randomly divided into 3 groups,with 8 teeth each group.Three self-etching adhesives were used:Clearfil SE Bond(Kuraray Company,Japan),G-bond Plus(GC Company,Japan),Single bondTM Universal(3M Company,USA).The instant micro-tensile bonding strength was tested.Fracture type was observed with the microscope.The results were statistically analyzed by SPSS 17.0 software,and the difference between groups were tested by T Test,with p<0.05 statistical significance.Results?The instant micro-tensile bonding strength of SE(n=80),GC(n=80)and Single bond(n=80)were:55.70±11.07MPa,52.85±7.54mpa and 62.8218.70MPa respectively.The instant micro-tensile bonding strength of Single bond was higher than that of SE and GC,and the difference was statistically significant.?The different fracture types were found in three groups.In 80 SE,19 fractures occured in dentin,10 in composite and 12 in interfaces;In 80 GC cases,18 fractures oecured in dentin,8 in composite resins and 6 in interfaces;In 80 Single bond cases,35 fractures occured in dentin,18 in composite resins and there's no fracture occured in interfaces.ConclusionThe instant micro-tensile bonding strength of Single bondTM Universal(3M Company,USA)is significantly higher than that of Clearfil SE Bond(Kuraray Company,Japan)and G-Bond plus(GC Company,Japan).The bonding strength of Single bondTTM Universal is probably much greater than that we measured in the test,which can be used as a reliable choice of adhesive in clinical application.Part two Comparative study on bonding durability with dentin among the three kinds of self-etch adhesives under the condition of artificial salivaObjectiveTo study the bonding durability with dentin of three different self-etching adhesives;To study the influence of artificial saliva on the bonding aging within three kinds of self-etching adhesives and provide some laboratory data for the long-term effect of the eighth-generation universal adhesive.MethodsThe remaining parts of the specimens prepared by part one were dipped in artificial saliva for 6 months,and the fracture type of specimen was observed by the microscope.The results were statistically analyzed by SPSS 17.0 software,and the difference between groups was tested by t test,with p<0.05 is the statistical significance.Results? After 6 months preservation in the artificial saliva,the micro-tensile bonding strengtth of SE,GC and Single bond were as follows:13.51±4.99MPa,43.5316.82MPa and 49.13±6.58MPa,statistical analysis among the three groups were significantly different.? There were significant differences between the instant bonding strength and the bonding strength after 6 months in artificial saliva among three self-etching adhesives(p<0.05),in which the bonding strength of GC group decreased at least.?The different fracture types were found in three groups after 6 months in the artificial saliva.In SE,all fractures occured in interface.In 80 GC cases,16 fractures occured in dentin,4 in composite resins and 24 in interfaces.In 80 Single bond cases,28 fractures were fond in dentin,8 in composite resins and 19 in interfaces.ConclusionSingle bondTM Universal has the outstanding performance after 6 months in artificial saliva because of its high bonding strength and good bonding durability.Single bondTM Universal can provide a persistent and reliable clinical bonding effect.