Evaluation of Forces Generated on Three Different Rotary File Systems in Apical Third of Root Canal using Finite Element Analysis

Abstract

Aim: Aim of the study is to evaluate the distribution of forces on the instrument in the apical 3rd of curved canal with three Nickel Titanium rotary systems. Methodology: Three brands of instruments (ProTaper Universal; DENTSPLY Maillefer, RevoS; MicroMega and Hyflex; Coltene-Whaledent, Allstetten, Switzerland) were scanned with the Laser assisted computerized scanner to produce a real-size, 3-dimensional (3-D) model for each. The stresses on the instrument during simulated shaping of a root canal were analyzed numerically by using a 3-D finite element package, taking into account the nonlinear mechanical behavior of the nickel-titanium material. Results: RevoS shows lowest values for force generation in the apical 3rd of canal as compared to Protaper which shows highest values, while Hyflex shows intermediate values for forces. Conclusion: With FE simulation of root canal shaping by 3 files, it was observed that different instrument designs would experience unequal degree of force generation in canal, as well as reaction torque from the root canal wall.

Keywords

• finite element analysis
• niti rotary files
• residual stresses
• screwing
• stress distribution