FINITE ELEMENT STRESS ANALYSIS OF TWO ROTARY SINGLE FILES IN DIFFERENT CANAL CURVATURES

Abstract

Background: Proper biomechanical preparation of root canals is fundamental to successful endodontic therapy. Curved canal resulted in endodontic intricacy. Formation of step, root canal deviation, and instrument separation are the most common complications during preparation of curved root canals. Aim of this study: The aim of this work is to use finite element analysis to evaluate the effect of different degrees of canal curvature on the stresses falling on two different single rotary files.Methods: Three finite element models were designed to simulate three canal curvatures (2°, 30°, 45°), then each of the two file systems were used to simulate the filling motion on each curvature forming six models. Group Ⅰ (Wave One Gold models) that divided into G Ⅰ(N), G Ⅰ(M), G Ⅰ(S) and G Ⅱ (One Curve) that divided into G Ⅱ(N), G Ⅱ(M), G Ⅱ(S)according to degree of canal curvature. Using COMSOL software 2020 to simulate the motion and the applied stress. VON MISES stress values were obtained to analyse the difference in studied groups.Results: The highest stress was 515.36 Mpa with Group ⅠS, 435.13 Mpa with Group ⅠM and 375.42 Mpa with Group ⅠN. While it was 565.17 Mpa with G ⅡS, 472.87 Mpa with G ⅡM and 405.71 Mpa with G ⅡN. Thus, the stress generated in the group Ⅰ was lower than group Ⅱ. Conclusion: Wave One Gold revealed lower Von Mises stress values than One Curve. Increased canal curvature resulted in generation of more amount of stress.