Influence of defects in solution irrigating dentinal training after preparation with System Reciproc®

Abstract Introduction Different sodium hypochlorite concentrations are available for use during the mechanical preparation of root canals by reciprocating instruments. Because of the speed with which the channel is instrumented in this new reciprocating kinematics, higher concentrations of sodium hypochlorite (NaOCl) has been recommended. Thus, it is opportune to research to evaluate whether the irrigant NaOCl solution enhances the possibility of formation of dentinal defects caused by Reciproc system. Objective To analyze the influence of irrigating sodium hypochlorite solution in the formation of dentinal defects caused by Reciproc® instrumentation system. Material and method We used 60 extracted first premolars were divided into two groups (G1) NaOCl 5.25% (n = 30); (G2 Control) Distilled water (n = 30), only the buccal conduit was instrumented with Reciproc® system and irrigated with the solutions. All the crowns of the teeth were cut perpendicular to the long axis, and the roots included in alveoli and simulated periodontal ligament. Palatal conduits were not instrumented or irrigated, because they served as a control for the specimen itself. At the end of the instrumentation, the roots were cut at 2, 4, 6 and 8 mm from the apical foramen and taken to the stereoscopic microscope to assess and record the formation of dentinal defects. Result Dentinal defects were found in the control group (G2) and sodium hypochlorite 5.25% group (G1), but no statistically significant difference between them (p> 0.05). Conclusion Sodium hypochlorite not triggered dentinal defects changes when used in combination with instrumentation for Reciproc® system.

摘要 引言：目前采用往复式器械进行根管机械预备时，可使用不同浓度的次氯酸钠（sodium hypochlorite，NaOCl）。由于该新型往复运动学的根管预备速度更快，临床推荐使用更高浓度的次氯酸钠（NaOCl）。因此，有必要开展相关研究，评估次氯酸钠冲洗液是否会增加Reciproc®器械系统根管预备引发牙本质缺陷（dentinal defects）的风险。

目的：分析次氯酸钠冲洗液对Reciproc®器械系统预备过程中牙本质缺陷形成的影响。

材料与方法：选取60颗拔除的第一前磨牙，分为两组：G1为5.25%次氯酸钠组（n=30），G2为对照组（蒸馏水组，n=30）。仅对颊侧根管采用Reciproc®系统进行预备，并使用对应溶液冲洗。所有牙冠均沿与牙长轴垂直方向截断，将牙根植入牙槽窝模型并模拟牙周膜；腭侧根管未进行预备与冲洗，作为标本自身的对照。预备完成后，在距根尖孔2、4、6、8mm处截取牙根片段，置于体视显微镜下观察并记录牙本质缺陷的形成情况。

结果：对照组（G2）与5.25%次氯酸钠组（G1）均发现牙本质缺陷，但两组间差异无统计学意义（p>0.05）。

结论：联合Reciproc®器械系统进行根管预备时，次氯酸钠不会诱导牙本质缺陷的产生。