Comparision Of The Preparation Effect By ProTaper Next,S3 And Reciproc Instruments In Curved Root Canal Preparation

Objective: The aim of this experiment is to prepare the middle and severe curved root canal of the isolated teeth,compare the preparation effect of ProTaper Next,Reciproc and S3 on the shaping ability by using cone-beam computed tomography and cleaning ability of root canal walls by using scanning electronic microscopy.Methods : Thirty teeth with moderately and severely curved root canal were employed from extracted human first and second molars for this vitro study.By using cone-beam computed tomography,got the values of root canal curvature.Then according to the values,samples were divided into 10 groups,and 3 teeth every group were randomly divided into 3 groups,group S3,group Reciproc and group ProTaper Next.The canals were respectively prepared according to manufacturer?s instructions.Pre-and Post-instrumentation CBCT imagines were captured,measured the central axis transportation at levels of 1mm,3mm,5mm,7mm and 9mm from the apex and straightened curvature of root canals Then those roots were spilit longitudinally by cutting along the root.Using scanning electronic microscopy got the pictures of the root canal surface,observed and evaluated the debris and smear layer in the surface of the apical 1/3,middle1/3 and coronal1/3.Results: ProTaper Next maintained the canal curvature best among the 3 groups(P<0.05).ProTaper Next created least canal transportation in all evaluated distances from the apex(P<0.05),especially in 1mm,3mm,7mm and 9mm.Reciproc created more canal transportation in 7mm and 9mm from the apex than S3.The debris scores: at the coronal 1/3 and middle 1/3 areas,there was statistical differences between group P and group S,also between group R and group S(P?0.5);at the apical 1/3 areas,there was statistical differences between group R and group S(P?0.5).The smear layer scores: at the coronal 1/3 and middle 1/3 areas,there was statistical differences between group P and group S(P?0.5);at the apical 1/3 areas,there was no statistical differences among three groups(P>0.5)Conclusions: ProTaper Next showed a better central axis transportation than S3 and Reciproc and maintained the riginal curvature of root canals best among the three groups.The cleaning ability of Protaper Next and Reciproc were better than S3.