ABSTRACT
Introduction: Biomechanical preparation of root canals isone of the main steps in achieving endodontic success dueto enabling bacterial elimination, removal of debris, andfacilitating obturation. The aim of this study was to comparethe incidence of dentinal cracks observed in the canal wallafter canal instrumentation with 3 single-file systems and theProTaper system (Dentsply Maillefer, Switzerland).Material and Methods: Eighty mandibular premolars withsingle root canal were selected. Teeth were decoronated andmounted in resin blocks with simulated periodontal ligaments.They were divided into 4 experimental groups (n = 20); theninstrumented to the full working length with the ProTaper,OneShape (MicroMega, Besancon, France), Reciproc (VDW,Munich, Germany), and WaveOne Gold (Dentsply Malliefer)was performed. The roots were sectioned perpendicular to thelong axis at 3, 6, and 9 mm from the apex and were observedunder a stereomicroscope. The presence of cracks was noted.The chi-square test was performed to compare the appearanceof cracked roots between the experimental groups.Results: Cracks found after canal instrumentation with theProTaper, OneShape, and Reciproc and WaveOne Goldfiles, were 46.6%, 23.3%, 13.6%, 11.6% respectively. Thedifference between the experimental groups was statisticallysignificant (P < .001).Conclusion: Nickel-titanium instruments cause cracks in rootsurface or in the canal wall; Reciproc and WaveOne Gold filescaused less cracks than the ProTaper and OneShape files.
ABSTRACT
Background: Preparing and maintaining the original shape in conjunction with its disinfection, exclusive of any procedural error is mandatory in endodontic treatment. Nickel-titanium instruments are much more flexible than conventional stainless steel files combined with superior cutting efficiency. The purposes of this study were to measure and compare the canal transportation, centering ratio at different levels of simulated curved canals of the endodontic training resin blocks, which were instrumented by using of 4 Niti rotary endodontic systems’ Protaper Next, OneShape, Protaper Gold, and TwoShape. Material and Methods: Total 60 resin blocks were randomly divided into 4 groups of 15 canals each; the 1st group was prepared with Protaper Next instruments, the 2nd was prepared with OneShape, the 3rd was prepared with Protaper Gold instruments, and the 4th was prepared with the TwoShape. All were prepared for the size of 25. Removal of material was measured at 5 different levels: at the canal orifice, halfway to the orifice in the straight sections; the beginning of the curve; the crest of the curve; the endpoint. Pre and post-operative photos of the simulated canals were taken in a standardized technique. An assessment of changes has been determined using Photoshop and Digimizer Software. The data were analyzed statistically using Shapiro-Wilk, ANOVA by SPSS software version 21. Results: Regarding the canal transportation, the direction of transportation of rotary NiTi instruments was usually towards the inner aspect at middle parts of the canal, towards the outer aspect of the curve at the apex of the curve and the end of preparation. Conclusion: The TwoShape produced the least amount of canal transportation and preserved the original curvature of the canal more than the other systems evaluated in this study.
ABSTRACT
Objective:To investigate the shaping and cleaning ability of Reciproc(RE),OneShape(OS)and ProTaper(PT)in oval-shaped root canal preparation.Methods:The canals of 57 distal roots of mandibular first molars were randomly divided into 3 groups and prepared by RE,OS and PT respectively.The preparation time was recorded.After instrumentation,all root canal walls were examined under SEMand evaluated by scores of debris and smear layer.The 3D data and images of the roots of pre-and post-preparation were con-structed by Micro-CT scanning.Results:Group RE and OS showed lower scores of debris and smear layer than those in group PT at the apical level(P <0.05),and less preparation time (P <0.05).Before and after preparation,the changes of root canal morphological pa-rameters (including volume,surface,area,major diameter and minor diameter)in OS group were less than those in group RE and PT(P<0.05).The changes of canal curvature in group PT was larger than that in group RE and OS (P <0.05).Conclusion:RE and OS are more effective than PT in debridement and faster in root canal preparation.RE and OS can maintain the centering of original canal better than PT in the apical part of the root canal.The shaping ability of OS is weaker than that of RE and PT.
ABSTRACT
The cleaning and shaping of root canals is a major step in root canal treatment procedure, which aims at removal of all the tissue debris from the root canal space while removing the inner layers of root canal dentin. With Nickel titanium (NiTi) rotary instruments this goal is easier to achieve, even in curved root canals. The recently introduced Single file NiTi-rotary systems such as WaveOne, Reciproc, OneShape & F360 claim to be able to completely prepare and clean root canals with only one instrument. Use of single file rotary systems, are cost effective, time saving, reduce instrument fatigue and possible crosscontamination. The purpose of this article is to review single file Niti-Rotary systems for canal preparation.