Study On Apical Microleakage After ProTaper Next Preparation For Curved Root Canals

Objective:The purpose of this study is to compare the apical sealing ability of curved root canals prepared with ProTaper Next,ProTaper and M3.And the other aim of this paper is to compare the apical sealing ability of curved root canals that are well obturated by continuous wave of condensation technique and cold lateral condensation technique after prepared with ProTaper Next.Methods:According to the Schneider method,240 mandibular premolars with single canal(20°>curvature>10°)were chosen.A total of 180 teeth were selected randomly into part ? and randomly divided into 3 groups(n=60).The teeth were prepared with ProTaper Next,ProTaper and M3 respectively,and then obturated by cold lateral condensation technique.The remaining 60 teeth and the teeth prepared with ProTaper Next in part ? were included into part ?.The remaining 60 teeth were prepared with ProTaper Next and well obturated by continuous wave of condensation.Dye infiltration method and cross-section method were used to determine the influence of different NiTi instruments and different obturations on apical microleakage.Results:1.Longitudinal observation on using dye infiltration method of three root canal preparation instruments revealed that there was no significant difference among ProTaper Next,ProTaper and M3(P>0.05).2.Compared with ProTaper,the apical sealing ability of ProTaper Next was better at 1mm from the apical foramen(P<0.05),and there was no significant difference between ProTaper Next and M3(P>0.05).At 2 mm from the apical foramen,ProTper Next had better apical sealing ability than M3 and ProTaper(P<0.05)and there was no significant difference between M3 and ProTaper(P>0.05).There was no significant difference at 3 mm from the apical foramen among ProTper Next,ProTper and M3.3.Longitudinal observation on using dye infiltration method revealed that there is no significant difference in apical microleakage between continuous wave of condensation technique and cold lateral condensation technique(P>0.05).4.There was no significant difference in apical microleakage between continuous wave of condensation technique and cold lateral condensation technique when compared by cross-section method(P>0.05).Conclusion:ProTaper Next had the best apical sealing ability,followed by M3,and ProTaper.There was no significant difference in apical microleakage between continuous wave of condensation technique and cold lateral condensation technique to obturate curved root canals prepared with ProTaper Next in short term.