Centering ability and canal transportation of : ProTper,Mtwo,WaveOne,Reciproc in simulated curved canals (A comparative study)

Abstract

Background: this study was conducted to compare the centering ability and canaltransportation of: Protaper, Mtwo, WaveOne, Reciproc in simulated curvedcanals.Materials and methods: Eighty simulated curved canals of 40° curvature weredivided into four groups and prepared to an apical size 25 using a crown-downtechnique for ProTaper instruments and single length technique for Mtwoinstruments and single file technique for WaveOne and Reciproc instruments. Thefollowing parameters were evaluated: outer and inner canal transportation andthe centering ability. The measurements were carried out at five different levels.Pre-and postoperative images of the canals were taken at 40X magnification byaid of stereomicroscope. An assessment of the canals shape was determined usingPhotoshop CS2 and AutoCAD software. The data were analyzed statistically usingANOVA and LSD test.Results: Considering canal transportation, the direction of transportation of rotaryNiTi instruments was usually toward the inner aspect at middle parts of the canaland toward the outer aspect of the curve at the apex of curve and the end ofpreparation. Waveone and Reciproc files were showed a better maintaining itsoriginal curvature with less straightening and transportation especially at the endof preparation of simulated canals. WaveOne and Reciproc instruments obtainedbetter centering ability at all levels especially at the end point of preparationcomparing with Protaper and Mtwo instruments.Conclusions: WaveOne and Reciproc instruments maintained the original curvaturesignificantly better than ProTaper and Mtwo.