| With the development of adhesives,oral adhesive repair is widely used.But the adhesion durability of dentin is still not optimistic.Various enzymes,bacteria and other factors in oral cavity will lead to the destruction of adhesive interface and affect the stability of dentin adhesion.Nanoleakage is a common cause affecting the bond durability.Nanoservation is the formation of microscopic pores,measured at the nanoscale,between the mixing layer and the normal dentin.The metabolites of various bacteria in the mouth,such as acids,enzymes and water,can enter this pore,further leading to the degradation of the binding interface.The various components infiltrated into the bonding interface affect the bonding durability through the following reasons :(1)the presence of water will lead to resin hydrolysis degradation,accelerate the monomer precipitation(2)some bacteria acid production,can activate matrix metalloproteinase activity,leading to the degradation of exposed collagen fibers in the interface.Objective:In this study,laser confocal microscopy was used to compare and analyze the microscopic morphology of dentine bonding interface with different concentrations of EDC at different time points from the perspective of nanoleakage through aging test,so as to provide experimental basis for clinical improvement of dentine bonding effect.Method:Collect out within A month of fresh without caries molar 100 according to the coating pretreatment agent type were randomly divided into 5 groups(n=20),respectively,the experimental group(A)0.3 mol/L EDC(B)0.5mol/L EDC(C)1 mol/L EDC group,(D)chloride group has set as the positive control group,(E)PBS group for blank control group,each group completely remove tooth surface enamel,600 mesh silicon carbide abrasive paper surface grinding essence,after 35% phosphoric acid corrosion,60 s preprocessing dentine surface,line resin restoration.More than five experimental group according to different aging conditions were randomly divided into two groups(n = 10):1 set for immediate nano leakage measurement,2 groups for aging nanoleakage measurement after aging all soaking specimens after psychro-thermal cycles in rhodamine B dye solution for 24 h,without aging group in 24 h after dyeing processing directly binding to complete all specimens with low speed cutting machine in parallel to the tooth length axis under running water cut,10 groups of specimens respectively in laser confocal microscope,measure and recordResults:In the non-aging group,compared with the two control groups,the length of the nanometer leakage immediately after the bonding interface was reduced by the use of carbinimide solution,but there was no significant difference in the length of the nanometer leakage measured between the experimental group and the control group(P>0.05).After 5000 cycles of heat and cold,there was a certain statistical difference between the experimental group and the control group(P<0.05).Among them,the length of nanometer leakage was the highest in the 1M group.Compared with chlorhexidine group,the inhibition effect of 0.3M and 0.5M groups on nanoleakage was not significantly improved.The 1M group promoted the occurrence of nanometer leakage in this experiment,and the difference was statistically significant.On the other hand,compared with the PBS group,the occurrence of nanometer leakage in the 0.3M group slowed down to a certain extent,but there was no statistical difference between the groups(P>0.05).0.5M and CHX groups had strong inhibitory effect on the nano leakage,and the difference was statistically significant(P<0.05).There was no significant difference between the two groups.Nanoleakage was increased in the 1M group,with no statistical difference.The length of nanoleakage increased after aging in all the experimental groups compared with the non-aging group.The degree of increase was in the order of 1M group,PBS group,0.3M group,CHX group and 0.5M group.Conclusion:1.As an MMPs inhibitor and collagen cross-linking agent,carbodiimide increased the length of nanometer leakage in both the non-aging group and the aging group compared with the positive control group of chlorhexidine,and the difference in the 1M group was statistically significant.Therefore,the effect of EDC in inhibiting nanometer leakage was not better than that of chlorhexidine2.Compared with the blank control group of PBS,carbinimide,as an MMPs inhibitor and collagen cross-linking agent,reduced the nanometer leakage in the non-aging group except the 1M group.There was no significant statistical difference in the length of each group.After 5000 cycles of heat and cold,the pretreatment of 0.5mol/L carbon diimide slowed the nanoleakage.0.3mol/L and 1mol/L have no obvious effect on the occurrence of nanoleakage. |
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