Moreira Edson Jorge Lima, Antunes Henrique Dos Santos, Vieira Victor Talarico Leal, Cavalcante Daniele Moreira, Oliveira Henrique Eduardo, Oliveira Diogo da Silva, DE-Deus Gustavo, Silva Emmanuel João Nogueira Leal da
Universidade Federal Fluminense - UFF, School of Dentistry , Department of Endodontics , Niterói , RJ , Brazil .
Universidade do Grande Rio - Unigranrio, School of Dentistry , Department of Endodontics , Rio de Janeiro , RJ , Brazil .
Braz Oral Res. 2021 Feb 12;35:e021. doi: 10.1590/1807-3107bor-2021.vol35.0021. eCollection 2021.
The aim of the present study was to evaluate the cyclic fatigue, torsional resistance and surface roughness of Reciproc R25 instruments in four different situations, namely as new instruments and as instruments tested after clinical preparation of one, two or three maxillary molars with four root canals. The total time required to perform each root canal preparation was recorded. Cyclic fatigue resistance was determined by the time to fracture using a customized testing device (n = 10 per group). The torsional test evaluated the torque and angle of rotation to failure according to ISO 3630-1 (n = 10 per group). The roughness of the working parts of new and used instruments was evaluated with a profilometer (n = 5 per group). Statistical analysis was performed using one-way ANOVA and Tukey's test. The level of significance was set at 5%. No fractures or deformations were observed after clinical use. Higher preparation time was needed during the third use of the instruments for all root canals (p < 0.05). There were no significant differences among the groups in regard to either cyclic fatigue or torsional resistance (p > 0.05). Regarding the roughness measurements, groove depth was higher on new and one- versus two- or three-maxillary-molar-prepared instruments (p < 0.05). It can be concluded that the clinical use of Reciproc instruments increased preparation time and decreased surface roughness. However, clinical use did not affect the cyclic fatigue or torsional resistance of the Reciproc instruments.
本研究的目的是评估Reciproc R25器械在四种不同情况下的循环疲劳、抗扭性和表面粗糙度，这四种情况分别为新器械，以及在对一颗、两颗或三颗有四个根管的上颌磨牙进行临床预备后测试的器械。记录每次进行根管预备所需的总时间。使用定制测试装置通过断裂时间来确定循环疲劳抗力（每组n = 10）。扭转测试根据ISO 3630 - 1评估断裂时的扭矩和旋转角度（每组n = 10）。使用轮廓仪评估新器械和使用过的器械工作部分的粗糙度（每组n = 5）。采用单因素方差分析和Tukey检验进行统计分析。显著性水平设定为5%。临床使用后未观察到断裂或变形情况。所有根管在器械第三次使用时需要更长的预备时间（p < 0.05）。在循环疲劳或抗扭性方面，各组之间无显著差异（p > 0.05）。关于粗糙度测量，新器械以及预备一颗上颌磨牙与预备两颗或三颗上颌磨牙的器械相比，沟槽深度更高（p < 0.05）。可以得出结论，Reciproc器械的临床使用增加了预备时间并降低了表面粗糙度。然而，临床使用并未影响Reciproc器械的循环疲劳或抗扭性。
