机用镍钛器械Mtwo及K3预备磨牙弯曲根管成形能力的比较

背景：重度弯曲根管的预备是临床根管预备的难点，如预备不当容易出现台阶、根管偏移、根尖孔敞开等并发症，影响根充质量和根尖封闭性，因此选择切削能力和成形能力俱佳的根管预备器械对与弯曲根管预备效果的保证有着重要意义。目的：比较Mtwo、K3机用镍钛器械与不锈钢手动K-file预备磨牙重度弯曲根管的成形效果。方法：将30颗新鲜拔除的人离体上颌第一磨牙重度弯曲近颊根管随机均分为3组，分别采用Mtwo机用镍钛器械、K3机用镍钛器械与不锈钢手动K-file进行根管预备。记录3组根管预备前后根管影像中器械尖端所在位置，测量并比较3组间根管弯曲度的变化、工作长度变化和操作时间。结果与结论：根管预备前，3组根管弯曲度比较差异无显著性意义(P > 0.05)；根管预备后，Mtwo机用镍钛器械组、K3机用镍钛器械组根管弯曲度变化小于不锈钢手动K-file组(P < 0.01)，Mtwo机用镍钛器械组、K3机用镍钛器械组根管弯曲度变化比较差异无显著性意义(P > 0.05)。3组根管预备时间比较差异有显著性意义(P < 0.01)，Mtwo机用镍钛器械组最短，不锈钢手动K-file组最长。3组根管预备后根管工作长度改变比较差异无显著性意义(P > 0.05)。表明Mtwo与K3机用镍钛器械预备后牙弯曲根管时效率高、成形能力强。中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程全文链接：

Shaping ability of rotary nickel-titanium Mtwo versus K3 in severely curved root canals

BACKGROUND:Severely curved root canal preparation is the difficulty during clinical root canal preparation, and improper preparation may induce complications such as stage, root canal offset and apical open, which affect the quality of root canal preparation and apical closure. Therefore, it is important to choose a root canal preparation instrument which has the best cutting and forming ability.OBJECTIVE:To compare the shaping ability of Mtwo nickel-titanium rotary instruments, K3 nickel-titanium rotary instruments and stainless steel K-files for the preparation of curved root canals.METHODS:A total of 30 severely curved root canals of freshly extracted human maxillary molars were randomly divided into three groups, with 10 canals in each group. The canals were prepared by Mtwo instruments, K3 instruments and K-files, respectively. The instrument’s tip location in pre- and post-instrumentation radiographs of the three groups was recorded; the changes of root curvature, working length and working time in the three groups were measured and compared.RESULTS AND CONCLUSION:The root curvature showed no significant difference in the three groups before preparation (P > 0.05). The changes of root curvature after root preparation in Mtwo instrument and K3 instrument groups were significantly less than that in K-files group (P < 0.01), and no significant difference was found between Mtwo instrument group and K3 instrument group (P > 0.05). The root canal preparation time in the three groups showed significant differences (P < 0.01), which was the shortest in Mtwo instrument group and the longest in K-files group. The changes of working length after root preparation in the three groups showed no significant difference (P > 0.05). Mtwo nickel-titanium rotary instruments and K3 nickel-titanium rotary instruments are have high efficacy and strong shaping ability in preparing curved root canals.