Citation Information :
Vivacqua FD, Canto M, Candeiro GT, Vasconcelos BC, Vivacqua-Gomes N. Durability of Two R-Phase Rotary Systems used in the Mechanical Instrumentation of Dilacerated Root Canals. J Contemp Dent Pract 2019; 20 (4):405-408.
Aim: This study was aimed to analyze, through an ex vivo test, the durability of two rotary systems used in curved root canals of extracted molars.
Materials and methods: At first, 150 upper and lower molars were selected, presenting curvature at least in one of the root canals. They underwent access cavity and radiographed with a # 15 file into the canal to determine their maximum curvatures, classified as schneider. The teeth with one or more curved canals were included in this study. Finally, 120 curved root canals were statistically divided into six sets of 20 curved canals. Two rotatory systems, K3 XF (RCS sequence) and twisted file (Large Kit), both treatment R-Phase, were analyzed. Three kits were used for each system, each one instrumented one of the six sets of 20 curved canals. File deformations were noted, and the files were used until a fracture occurs or until completion of 20 canals preparation. Fractured files before the end of the instrumentation of the 20 canals were replaced, continuing the full instrumentation set. Statistical analysis was performed by analysis of variance (ANOVA) (p > 0.05), and a qualitative assessment was also made.
Results: It was found that there was no statistical difference between the K3 XF and TF systems regarding fracture.
Conclusion: There were no statistical differences between the K3 XF systems in the RCS sequence and the twisted file kit Large system, as to the number of instrumented conduits to the deformation or fracture.
Clinical significance: The findings of this study reinforce that, it is necessary to choose files that support curved roots preventing accidents inside the root canal. Therefore, it is important for professionals to have knowledge and command of these protocols to obtain more satisfactory results.
Gambarini G, Plotino G, Grande NM, et al. Mechanical properties of nickel-titanium rotary instruments produced with a new manufacturing technique. Int. Endod J 2011;44(4):337–341.
Castello-Escriv. R, Alegre-Domingo T, Faus-Matoses V, et al. In vitro comparision of cyclic fadigue resistence of protaper, waveone and twisted file. J Endod 2012;38(11):1521–1524.
Cheung GSP, Oh SH, Há JH, et al. Effect of torsional loading of nickel-titanium instruments on cyclic fatigue resistance. J Endod 2013;39(12):1593–1597.
Gambarini G, Gergi R, Naaman A, et al. Cyclic fatigue analysis of twisted file rotary NiTi instruments used in reciprocating motion. Int Endod J 2012;45(9):802–806.
Wolcott S, Wolcott J, Ishley D, et al. Separation incidence of protaper rotary instruments: A large cohort clinical evaluation. J Endod 2006;32(12):1139–1141.
Bhagabati N, Yadav S, Talwar S. An in vitro cyclic fatigue analysis of different endodontic nickel-titanium rotary instruments. J Endod 2012;38(4):515–518.
Vieira MVB. A influência da geometria de canais artificiais na fratura de instrumentos de NiTi por flexão rotativa contínua: [Tese]. Rio de Janeiro: Faculdade de Odontologia da Universidade Estácio de Sá;
Capar ID, Ertas H, Ok E, et al. Comparative study of different novel nickel-titanium rotary systems for root canal preparation in severely curved root canals. J Endod 2014;40(6):852–856.
Caballero H, Rivera F, Salas H. Scanning electron microscopy of superficial defects in twisted files and reciproc nickel–titanium files after use in extracted molars. Int Endod J 2015;48(3):229–235.
Yared G. Canal preparation using only one Ni-Ti rotary instrument: preliminary observations. Int Endod J 2008;41(4):339–344.
Wu J, Lei G, Yan M, et al. Instrument separation analysis of multi-used ProTaper Universal rotary system during root canal therapy. J Endod 2011;37(6):758–763.
Wan J, Rasimick BJ, Musikant BL, et al. A comparison of cyclic fatigue resistance in reciprocating and rotary nickel-titanium instruments. Aust Endod J 2011;37(3):122–127.
Pérez-Higueras JJ, Arias A, Macorra J, et al. Differences in cyclic fatigue resistance between ProTaper Next and ProTaper Universal instruments at different level. J Endod 2014;40(9):1477–1481.
Ebihara A, Yahata Y, Miyara K, et al. Heat treatment of nickel-titanium rotary endodontic instrument effects on bending properties and shaping abilities. Int Endod J 2011;44(9):843–849.
Lopes HP, Vieira MVB, Elias CN, et al. Influence of the Geometry of curved artificial canals on the fracture of rotary nickel-titanium instruments subjected to cyclic fatigue tests. J Endod 2013;39(5):704– 707.
Plotino G, Costanzo A, Grande NM, et al. Experimental evaluation on the influence of autoclave sterilization on the cyclic fatigue of new nickel-titanium rotary instruments. J Endod 2012;38(2):222–225.
Kim HC, Yum J, Hur B, et al. Cyclic fatigue and fracture characteristics of ground and twisted nickel-titanium rotary files. J Endod 2010;36(1):147–152.
Zhao D, Shen Y, Peng B, et al. Micro–computed tomography evaluation of the preparation of mesiobuccal root canals in maxillary first molars with hyflex cm, twisted files, and k3 instruments. J Endod 2013;39(3): 385–388.
Rodrigues RCV, Lopes HP, Elias CN, et al. Influence of different manufacturing methods on the cyclic fatigue of rotary nickeltitanium endodontic instruments. J Endod 2011;37(11):1553–1557.