Canal Transportation And Centering Ability Of Different NiTi Rotary Endodontic Instruments:Meta-Analysis

Aim: To systematically review articles on canal transportation and/or centering ability of different nickel-titanium rotary endodontic instruments and subject results to metaanalysis.Materials and Methods: A comprehensive search was done on canal transportation and centering ability of different NiTi rotary endodontic instruments(both continuous rotation and reciprocating motion)by selecting articles published in peer reviewed journals using PubMed,ScienceDirect and Cochrane Library.Inclusion and exclusion criteria were established.A data was made by tabulating Authors' name,publication year,sample size,root curvature of included extracted human teeth,mean and standard deviation,and PICOS was generated to guide meta-analysis.Two analyses were done including all the studies that were comparable and inclusive i.e.one comparing ProTaper with other rotary NiTi files and another comparing reciprocating files like WaveOne,Reciproc,ProTaper,ProTaper Next and Twisted File with rotary NiTi files.Standardized mean differences were calculated for each study using Revman 5.3.Results: NiTi rotary endodontic instruments like Twisted File,Revo-S,Greater Taper,RaCe,HeroShaper,OneShape or WaveOne showed less canal transportation than ProTaper.Similarly,NiTi rotary endodontic instruments like Twisted File,OneShape or BioRace are better for clinical use in root canal cleaning and shaping than the reciprocating instruments like WaveOne and Reciproc due to significant less canal transportation.But there was no significant difference in centering ability in either analyses.Conclusion: Newer NiTi rotary files like Twisted File,OneShape,WaveOne,Revo-S are better considering canal transportation which may be due to implementation of modern methods to manufacture them like thermally processed M-wire,R-phase heat treated and twisted,asymmetric cross-sectional geometry,etc.