Discipline of Endodontic, Department of Restorative Dentistry, School of Dentistry, University of São Paulo, São Paulo, SP, Brazil.
Int Endod J. 2019 Jan;52(1):13-18. doi: 10.1111/iej.12982. Epub 2018 Jul 27.
To assess the fracture incidence of instruments from single-file reciprocating systems when used by students in an endodontic graduate programme.
Dental records and periapical radiographs of patients treated by students on an endodontic graduate programme using reciprocating systems were assessed. Data on tooth type, number of treated root canals, number of fractured instruments, fragment size, angle, radius, arc length and position of root canal curvature where fractures occurred were tabulated for analysis. The risk of fracture was calculated for each group of teeth, root canal and root thirds, whilst the incidence of fractures reported for the reciprocating systems was compared using the chi-squared test at 5% significance level.
Overall, 2056 root canals (826 teeth) from 810 patients were included. The incidence of fractured files from single-file reciprocating systems in relation to a number of instrumented canals was 0.92%. Fracture rates of 0.84% and 0.93% were found in 830 and 1226 root canals instrumented with WaveOne and Reciproc systems, respectively. No significant differences were observed between the systems. The highest fracture rate was 52.6% in the mesiobuccal root of mandibular molars. The central angle, radius and arc length of the curvature of root canals where the instruments fractured ranged from 58° to 84°, from 1.7 to 7.2 mm and from 2.4 to 7.6 mm, respectively.
The use of WaveOne and Reciproc single-file reciprocating systems in an endodontic graduate programme was associated with a low incidence of instrument fractures.
评估学生在牙髓学研究生课程中使用单丝往复式系统时器械折断的发生率。
评估了使用往复式系统接受牙髓学研究生课程学生治疗的患者的牙科记录和根尖放射线照片。对牙齿类型、治疗根管数量、折断器械数量、碎片大小、角度、半径、弧长和根管弯曲处的位置进行了制表分析。计算了每组牙齿、根管和根的第三部分的骨折风险，同时使用卡方检验比较了报告的往复式系统的骨折发生率，显著性水平为 5%。
总共纳入了 810 名患者的 2056 个根管（826 颗牙齿）。单丝往复式系统中折断文件的发生率与仪器根管数量有关，为 0.92%。在 830 个和 1226 个根管中，WaveOne 和 Reciproc 系统的折断率分别为 0.84%和 0.93%。两个系统之间没有观察到显著差异。下颌磨牙近中颊根的折断率最高，为 52.6%。器械折断的根管弯曲处的中央角、半径和弧长范围分别为 58°至 84°、1.7 至 7.2mm 和 2.4 至 7.6mm。
在牙髓学研究生课程中使用 WaveOne 和 Reciproc 单丝往复式系统与器械折断的发生率较低相关。
