Comparative Evaluation of Stress Distribution in Experimentally Designed Nickel-titanium Rotary Files with Varying Cross Sections: A Finite Element Analysis
| Autor: | Purushothaman Pranav Vanajassun, Shadir Bughari Basheer Ahamed, Kothandaraman Rajkumar, Sekar Mahalaxmi |
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| Rok vydání: | 2017 |
| Předmět: |
Dental Stress Analysis
Dental Instruments Root canal Finite Element Analysis 02 engineering and technology Bending Curvature Comparative evaluation Stress (mechanics) 03 medical and health sciences 0302 clinical medicine medicine Alloys von Mises yield criterion Humans General Dentistry Mathematics business.industry 020502 materials 030206 dentistry Structural engineering Finite element method medicine.anatomical_structure 0205 materials engineering Nickel titanium Stress Mechanical Dental Pulp Cavity business |
| Zdroj: | Journal of endodontics. 44(4) |
| ISSN: | 1878-3554 |
| Popis: | Introduction Single cross-sectional nickel-titanium (NiTi) rotary instruments during continuous rotations are subjected to constant and variable stresses depending on the canal anatomy. This study was intended to create 2 new experimental, theoretic single-file designs with combinations of triple U (TU), triangle (TR), and convex triangle (CT) cross sections and to compare their bending stresses in simulated root canals with a single cross-sectional instrument using finite element analysis. Methods A 3-dimensional model of the simulated root canal with 45° curvature and NiTi files with 5 cross-sectional designs were created using Pro/ENGINEER Wildfire 4.0 software (PTC Inc, Needham, MA) and ANSYS software (version 17; ANSYS, Inc, Canonsburg, PA) for finite element analysis. The NiTi files of 3 groups had single cross-sectional shapes of CT, TR, and TU designs, and 2 experimental groups had a CT, TR, and TU (CTU) design and a TU, TR, and CT (UTC) design. The file was rotated in simulated root canals to analyze the bending stress, and the von Mises stress value for every file was recorded in MPa. Statistical analysis was performed using the Kruskal-Wallis test and the Bonferroni-adjusted Mann-Whitney test for multiple pair-wise comparison with a P value Results The maximum bending stress of the rotary file was observed in the apical third of the CT design, whereas comparatively less stress was recorded in the CTU design. The TU and TR designs showed a similar stress pattern at the curvature, whereas the UTC design showed greater stress in the apical and middle thirds of the file in curved canals. All the file designs showed a statistically significant difference. Conclusions The CTU designed instruments showed the least bending stress on a 45° angulated simulated root canal when compared with all the other tested designs. |
| Databáze: | OpenAIRE |
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