Shaping ability of three rotary NiTi systems : Mtwo, K3, proTaper, in simulated curved canals ( part 1)‎

Abstract EN

Background: Part I of this study was conducted to compare the shaping ability of three rotary endodontic nickel-titanium systems (Mtwo, K3 and ProTaper), in simulated curved canals.

Materials and methods: Seventy five simulated curved canals of 40° curvature were divided into three groups and prepared to an apical size 30 using a crown-down technique for K3 and ProTaper instruments and single length technique for Mtwo.

The following parameters were evaluated: total canal diameter, outer and inner canal transportation and the centering ability.

The measurements were carried out at five different levels.

Pre-and postoperative images of the canals were taken at 40X magnification.

An assessment of the canals shape was determined using Photoshop CS2 soft ware.

The data were analyzed statistically using ANOVA and Student's t-test at 5% significant level.

Results: Considering canal diameter, ProTaper widened the canals more effectively at all levels except at the apical level which was less than K3.

The direction of transportation was usually toward the inner aspect at the middle part of the canal and toward the outer aspect at the coronal and apical parts.

Mtwo achieved better centering ability at all levels than ProTaper and K3.

K3 showed better centering ability than ProTaper at all levels except at the end point of preparation.

Conclusions: Mtwo rotary instruments maintained the original curvature significantly better than K3 and ProTaper.