Study On The Influence Of Biopure MTAD Root Canal Irrigation Fluid On Dentin Bond Strength Of Root Canal Wall

Objective :To improve the bond strength of the fiber pile,it directly affects the service life of the pile restoration.The surface treatment of fiber piles such as acid etching,sandblasting,silane coupling agent,tribochemical silicate coating,etc.can be performed;the flushing of the inner surface of the root canal can also be performed with physiological saline,EDTA,sodium hypochlorite,hydrogen peroxide,CHX,and the like.This experiment carried out research on the treatment of the smear layer on the inner surface of the root canal,and used a novel root canal washing solution to treat the root canal dentin smear layer.Through the use of different treatment methods to compare which treatment method is the best,so as to improve the bond strength of fiber posts,provide a basis for clinical use.Methods :40 single molar premolars were randomly divided into A,B,C,and D groups.A was the control group and B/C/D group was the experimental group.Group A: 10 ml NaCl treatment;Group B: 5 ml 17% EDTA and 5 ml 1.3% NaClO treatment;Group C: 5 ml Biopure MTAD and 5 ml 1.3% NaClO treatment;Group D: 10 ml Biopure MTAD treatment.The treated sample was randomly divided into two parts.One part was observed by scanning electron microscopy(SEM)to remove the smear layer on the surface of the specimen,and the other part was used to measure the bonding strength of the fiber post by the wafer pushing-out experiment.Results :In the first part,scanning electron microscope was used to observe the removing effect of the dentin smear layer of the root canal wall.The results showed that the number of dentinal tubules in group C revealed the most,followed by group B and group D,compared with the control group A,exposed dentin The number of small orifices has increased significantly.The number of dentinal orifices exposed in group A and D in the apical image was also significantly higher than that in group B.However,the number of exposed dentinal canals in the root canal and in the upper group B,C,and D were almost the same.The second part of the slice push-out experiment results showed that the increase of the bond strength of the root canal,the middle and the lower part of the root canal was the best in the group C,followed by the bond strength of the middle and upper fiber posts in the root canal of the three experimental groups.Significant changes(P>0.05),but in the root tip group C,D group compared to B group,the fiber pile bond strength has significant differences(P <0.05).The bond strength of the control group in group A was the lowest,and the bond strength of the fiber group in the three groups was significantly different from that in the control group(P<0.05).Conclusions :1.MTAD or combined with low concentration of NaClO treatment can better expose the dentinal orifice.2.MTAD or combined with low concentration of NaClO can significantly improve the bond strength of fiber post,and also have a good effect on the removal of apical 1/3 smear layer.It is beneficial to strengthen the firmness of fiber post crown repair and prolong the service life of fiber post crowns.