Effect Of Er,Cr:YSGG Pretreatment On Bond Strength Of Fiber Posts To Root Canal Dentin

ObjectiveThe aim of this report was to evaluate the effect of Er, Cr: YSGG laser irradiation on push-out bond strength of 3M fiber posts cemented to root canal dentin. So that providing a theoretical basis for clinical selection about appropriate pretreatments to root canal dentin.MethodsA total of 39 sound human mandibular premolars were randomly divided into A, B, C three groups after root canal treatment, decoronation and preparation of the post space. Root canal wall of group A were treated with Distilled water(control group), group B were treated with EDTA, Na CLO and ultrasound swing washing processing(control group), group C were treated with Er,Cr:YSGG laser. The treated 3M fiber post was cemented with Rely-X Unicem bond system in the root canal. To observe the microstructure characteristics in the root canal wall surface through the SEM, compared the mean shear bonding strengths to evaluate the effect of bond strength.Results(1) Electron microscope observation: Group A, there were smear layer in root canal wall surface, no dentinal tubules; Group B, the dentinal tubules were opened but there were still amount of debris in the root canal wall surface; Group C, after laser pretreatment, the dentinal tubules were opened, the root canal wall surface was clean and many pits were formation on the dentin surface.(2) Bond strength①In the upper root canal:group C and group A were significantly different(P <0.05); There were no significant differences in group C and group B(P >0.05). There were no significant differences in group A and group B(P > 0.05);②In the middle root canal:group C and group A were significantly different(P <0.05); group C and group B were significantly different(P <0.05); There were no significant differences in group A and group B(P > 0.05);③In the below root canal:There were no significant differences in group A, group B and group C(P > 0.05); There were no significant differences in different parts of each groups(P <0.05);ConclusionThe root canal wall surface treated with Er, Cr: YSGG laser could improve the effects of bond strength between fiber posts and root canal dentin.