Abstract:

Objective    To evaluate the clinical effects of two nickel-titanium （NiTi） instruments ［M3-Pro and Twisted File（TF）］ in preparation of molar curved root canals for the aged. Methods    A total of 240 first molars and second molars with curved root canals（25°-30°）that required root canal treatment were selected and randomly divided into two groups. The root canals were prepared with M3-Pro NiTi rotary instruments in the M3-Pro group and with TF NiTi rotary instruments in the TF group. For general analysis，all the cases are chosen from the newly diagnosed cases of patients about 60 - 70 years old in clinic from Jun. 2015 to Sep. 2017. Then the root canal preparation time，incidence of the pain after root canal preparation，effects of root canal obturation，and incidence of instrument separation were compared. Results    The average root canal preparation time in the M3-Pro group was（5.22 ± 1.12）min，whereas in the TF group it was（6.47 ± 0.93）min（t = -17.816，P < 0.05）. The incidence of endodontic inter-appointment emergences in the M3-Pro group was 3.3%，whereas in the TF group it was 2.5%（χ2 = 0.147，P > 0.05）. Adequate root canal filling in the M3-Pro group was 96.72%，whereas in the TF group it was 95.84%（χ2 = 0.463，P > 0.05）. Instrument separations were not found in both groups. There were 10 instruments damaged in the M3-Pro group and 21 instruments damaged in the TF group （χ2 = 4.482，P < 0.05）. Conclusion    M3-Pro instruments can make the preparation efficiently and reduce the incidence of endodontic inter-appointment emergences；in addition，it maintains a satisfactory anatomical shape of the root canal while significantly decreasing instrument separation. M3-Pro is suitable for the treatment of curved root canal，and has good clinical effect.

Key words: nickel-titanium instrument, curved root canal, root canal preparation

摘要：

目的    评价两种机用镍钛器械M3-Pro和Twisted File（TF）在老年人磨牙弯曲根管预备中的临床应用效果。方法    选择2015年6月至2017年9月在青岛市口腔医院牙体牙髓科门诊就诊的60 ~ 70岁因牙髓病需要行根管治疗的初诊患者215例，按Schneider测量法选择弯曲根管（25° ~ 30°）磨牙240颗，随机均分为M3-Pro组和TF组，分别用M3-Pro和TF机用镍钛器械进行根管预备，比较两组在根管预备时间、根管预备后疼痛反应、根管充填效果、器械分离和损伤情况等方面的差异。结果    M3-Pro组的根管预备时间为（5.22 ± 1.12）min，TF组为（6.47 ± 0.93）min，组间差异有统计学意义（t = -17.816，P < 0.05）；M3-Pro组根管治疗期间急症发生率为3.3%，TF组为2.5%，组间差异无统计学意义（χ2 = 0.147，P > 0.05）；M3-Pro组根管恰填率为96.72%，TF组为95.84%，组间差异无统计学意义（χ2 = 0.463，P > 0.05）；两组各使用镍钛器械120支，均未发生器械分离，M3-Pro组发生10支器械损伤，TF组发生21支器械损伤，组间差异有统计学意义（χ2 = 4.482，P < 0.05）。结论    M3-Pro能够高效率地进行根管预备，可有效降低根管治疗期间急症的发生，也能更好地保持根管解剖的原始走行，明显减少器械分离的发生，尤其适合弯曲根管的治疗，临床疗效较好。

关键词: 机用镍钛器械, 弯曲根管, 根管预备