Preliminary Study Of The Bonding Properties Of Resin Cements On Er, Cr: YSGG Laser-irradiated Dentin

Objective: The purpose of this study was to evaluate the bonding propertieschange of resin cements on Er, Cr: YSGG laser-irradiated dentin,and to explore theeffect of two surface treatments on bonding properties improvment of resin cements.Methods:(1)104dentin specimens were randomly assigned to8groups.Twotreatments were performed: high-speed diamond bur preparation(control group); Er,Cr: YSGG laser irradiation(laser group).Then four resin cements(RelyX ARC,Panavia F, RelyX Unicem and Clearfil SA Cement) were bonded onto the dentinsurfaces in both groups respectively.The bonded specimens were subjected to a shearload until facture occurred.Scanning electron microscope(SEM) was used to inspectthe interface morphology.(2) Seventy-eight dentin specimens were irradiated by Er,Cr: YSGG laser and randomly assigned to six groups.Then two surface treatmentswere performed: G-Bond（G）,Zinc-Zeolite（Z）,no treatment as a control group.Dentin specimens were bonded with two resin cements(Rely X Unicem、SA Cement)respectively,tested for shear bond strength(SBS) and observed using SEM.Results:1. The mean values in MPa SD of SBS test for Panavia F and Clearfil SACement in laser groups were statistically lower than control groups（P<0.05）, whileno significant differences were detected for RelyX ARC and RelyX Unicem(P>0.05);SEM showed that Er, Cr: YSGG laser has a poor influence on the resin-dentininterface of RelyX Unicem and Clearfil SA Cement,but the resin tags of RelyX ARCand Panavia F decreased in laser groups.2. The mean values in MPa SD of SBS test for group ZU and GU werestatistically higher than group U.The SBS for group GS was statistically higher than group S.But no significant differences existed between group ZS and group S. SEMshowed Rely X Unicem-dentin interface could be modified significantly byZinc-Zeolite and G-Bond. SA Cement-dentin interface could be improvedsignificantly by G-Bond,but Zinc-Zeolite has no effect on SA Cement-dentininterface.Conclusions:1. The bonding properties of RelyX ARC and RelyX Unicem demonstrated nosignificant changes on Er, Cr: YSGG laser-irradiated dentin, and the bondingproperties of Panavia F and Clearfil SA Cement significantly altered on laser-irradiated dentin.2. G-Bond and Zinc-Zeolite were effective surface treatments in terms ofbonding properties improvment for Rely X Unicem. G-Bond could result in improvedbonding properties for SA Cement. Zinc-Zeolite had no significant influence onbonding properties for SA Cement.