Three Common Adhesives And Their Combined Application With Chlorhexidine For Microleakage Of Composite Resins In Vitro

Background:As an important organ of the human body,Teeth are often affected by dental caries,wedge-shaped defects,tooth trauma and other dental diseases affecting their normal function.Composite resin is widely used in the direct repair of tooth defects due to their advantages of aesthetics and good clinical performance.Composite resin is a repairing material that relies on the bonding effect of adhesive.The microleakage of the bonding interface directly affects the success of the repair.How to improve the bonding interface tightness of the adhesives continuously has been a hot issue in our researches.Chlorhexidine is a non-specific and broad-spectrum inhibitor of matrix metalloproteinases?MMPs?,which has been widely studied for the microleakage of restoration of composite resins.there are few related studies on whether chlorhexidine is equally applicable for different adhesives.In our study,there is a comparative study among the microleakage of Single bond Universal adhesive?in total-etching mode and self-etching mode?,single bond2 total-etching adhesive and Clear Fil S3 self-etching adhesive,to further clarify the microleakage situation of various adhesives and the three adhesives combined with the MMPs inhibitor of chlorhexidine.The comparative study found that the effect of chlorhexidine on the microleakage of the three adhesives,to provide a certain experimental basis for guiding clinical application.Object:?1?To compare the situation of microleakage among single bond universal adhesive?in total-etching mode and self-etching?,single bond 2 total-etching adhesive and Clear Fil S3 self-etching adhesive after composite resin repair in vitro.?2?The situation of microleakage after the combined application of three adhesives with chlorhexidine.?3?To compare the effects of chlorhexidine on the microleakage of three adhesives,Provide a basis for clinical application.Materials and methods:80 premolars without obvious caries or cracks were removed in one month.They were randomly divided into two parts on average.Class V cavity were prepared on the buccal side of crown.Part 1:the teeth were randomly divided into4 groups,group A₁,B₁,C₁,and D₁,with 10 teeth in each group.In group A₁,the cavities were treated with distilled water and coated with Single bond Universal adhesive in the total-etching mode.In group B₁,the cavities were treated with distilled water and coated with Single bond Universal adhesive in the self-etching mode.In group C₁,the cavities were treated with distilled water and coated with Single bond2 adhesive in the total-etching mode.In group D₁,the cavities were treated with distilled water and coated with Clear Fil S3 adhesive in the self-etching mode.Part 2:the teeth were randomly divided into 4 groups,group A₂,B₂,C₂,and D₂,with 10 teeth in each group.The operations were almost the same as the Part 1.However,2%chlorhexidine replace distilled water to treat the cavities.Experiment 1 and experiment 2 were carried out simultaneously.The composite resin of Z350 were filled in layers under the same light conditions.The specimens were aged for 1 hour by 10%sodium hypochlorite.The specimens were soaked in 0.1%wt rhodamine B fluorescent agent for 24 hours in a constant temperature?37°C?water bath,then the specimens were cut into pieces after washing and drying.Observe the penetration of the fluorescent agent by a laser scanning confocal microscope.LAS-X software was used to measure the gingival and occlusal length of the total microleakage.SPSS22.0 statistical software was used to analyze the experimental data.Results:part 1:The results of one-way ANOVA showed that there was significantly difference among the four groups?F=45.884,P<0.05?.The microleakage of Group C₁was significantly higher than the group A₁?P<0.05?,and the group A₁was significantly higher than the group B₁and D₁?P<0.05?.There was no significant difference between group B₁and group D₁?P>0.05?.part 2:The results of one-way ANOVA showed that the differences among the four groups were statistically significant?F=10.929,P<0.05?.Pairwise analysis of each group founding that the microleakage of group C₂was significantly higher than the other three groups?P<0.05?,and there was no significant difference among groups A₂,B₂,and D₂?P>0.05?.Comparation of the two experiments:The difference between group A₁and group A₂was statistically significant?t=5.838,P<0.05?.The microleakage group A₁was significantly larger than that in group A₂.There was no significant difference between group B₁and group B₂?t=0.991,P>0.05?.The microleakage difference between group B₁and group B₂was not obvious.The difference between group C₁and group C₂was statistically significant?t=4.959,P<0.05?.The microleakage in group C₁was significantly larger than that in group C₂.There was no statistically significant difference between group D₁and group D₂?t=0.881,P>0.05?.The microleakage difference between D₁group and D₂group was not obvious.Conclusion:1.Among the three common adhesives,single bond2 showed the most obvious microleakage,followed by single bond Universal?in the total-etching mode?,and finally single bond Universal?in the self-etching mode?and Clear Fil S3.single bond Universal?in the self-etching mode?and Clear Fil S3 showed little microleakage.there is no obvious difference between single bond Universal?in the self-etching mode?and Clear Fil S3.2.After combined application of chlorhexidine,the microleakage of single bond2 was higher than single bond Universal?total-etching mode and self-etching mode?and Clear Fil S3.3.The microleakage of the three adhesives was alleviated after combined application of chlorhexidine.Chlorhexidine significantly improved the microleakage of Single bond Universal?in the total-etching mode?and Single bond2.While the microleakage of Single bond Universal?in the self-etching mode?and Clear Fil S3 was not significantly improved.