D Fife1, G Gambarini, L r Britto Lr. 1. Department of Endodontics, College of Dentistry, University of Florida, Gainesville, Florida 32610-0436, USA.
Abstract
PURPOSE: The purpose of this study was to evaluate the cyclic fatigue of ProTaper nickel-titanium (NiTi) rotary instruments (Tulsa Dental, Tulsa, Okla) after multiple clinical uses. STUDY DESIGN: Two hundred twenty-five ProTaper instruments were divided into 3 groups: A = 75 used as controls, B = 75 used in 2 molars (6-8 canals), and C = 75 used in 4 molars (12-16 canals). The number of rotations to breakage and the fractured tip length were recorded for each file and the mean was calculated by ANOVA. RESULTS: No S1-2 or F1-2-3 instrument separated during intracanal use, even if they were reused for a number of cases (x 4 molar cases). CONCLUSION: It is clear that prolonged reuse of NiTi rotary instruments strongly affects instruments' fatigue, but our data suggest the hypothesis that other factors (primarily errors and misuse) may be more accountable for intracanal instrument separation. Further studies could assess the cyclic fatigue of each instrument at different levels of the shaft by altering the radius of curvature.
PURPOSE: The purpose of this study was to evaluate the cyclic fatigue of ProTaper nickel-titanium (NiTi) rotary instruments (Tulsa Dental, Tulsa, Okla) after multiple clinical uses. STUDY DESIGN: Two hundred twenty-five ProTaper instruments were divided into 3 groups: A = 75 used as controls, B = 75 used in 2 molars (6-8 canals), and C = 75 used in 4 molars (12-16 canals). The number of rotations to breakage and the fractured tip length were recorded for each file and the mean was calculated by ANOVA. RESULTS: No S1-2 or F1-2-3 instrument separated during intracanal use, even if they were reused for a number of cases (x 4 molar cases). CONCLUSION: It is clear that prolonged reuse of NiTi rotary instruments strongly affects instruments' fatigue, but our data suggest the hypothesis that other factors (primarily errors and misuse) may be more accountable for intracanal instrument separation. Further studies could assess the cyclic fatigue of each instrument at different levels of the shaft by altering the radius of curvature.
Authors: Suzanny C S Martins; Jessica D Silva; Paula R Garcia; Ana C D Viana; Vicente T L Buono; Leandro A Santos Journal: Clin Oral Investig Date: 2022-01-17 Impact factor: 3.573
Authors: Victor Feliz Pedrinha; Juliana Melo da Silva Brandão; Oscar Faciola Pessoa; Patrícia de Almeida Rodrigues Journal: Open Dent J Date: 2018-02-28