倒敞法结合2 种机用镍钛锉预备重度弯曲后牙根管的应用研究

摘要

Objective: To evaluate the treatment efficacy of reverse flaring technique applied by two rotary instruments, Hero 642 and ProTaper, on complicated molar root canal preparation. Methods: 100 molars with curved root canals (maximum curved angle ≥25 degrees) suffered from pulpitis or periapicities were randomly divided into two groups. In experimental group reverse flaring technique was applied by rotary instruments while in control group reverse flaring technique was not adopted. 50 experimental teeth with curved canals were operated with K files, Hero 642 and ProTaper in sequence. Lateral condensation obturation method was utilized in both groups. Root canal preparation and obturation efficiency were evaluated by X-ray, root canal preparation time and complication incidence (1 year follow-up rate was 95%). Results: Reverse flaring technique applied by Hero 642 and ProTaper Ni-Ti rotary instruments on complicated (curved) root canal preparation in group A demonstrated better root canal coning and smoothness, without instrument fractures, while instrument fractures occurred in control group. Significant difference was found in exact root canal obturation rate and not enough full rate, root canal smoothness and postoperative pain between two groups(P<0.05). Conclusion: Reverse flaring technique applied by Hero 642 and ProTaper NI-Ti rotary instruments indicates complementary potencies, demonstrating satisfactory root canal shape and obturation effectiveness, and lower complication incidence. Reverse flaring technique applied by Ni-Ti rotary instruments is apt for medium/severe curved root canal preparation and worthy of clinical application.%目的:评价倒敞法结合Hero 642和ProTaper机用镍钛锉预备重度弯曲后牙根管的疗效.方法: 随机将100 颗患牙髓炎或根尖周炎、最大根管弯曲度≥25°的后牙分为2 组,各50 例.实验组(A组)采用倒敞法,而对照组(B组)不采用倒敞法机械预备.A组以机用开口锉根管中上端敞开后,手用K锉预备根尖,再先用镍钛器械Hero 642,后用ProTaper预备根管;B组则直接应用Hero 642和ProTaper冠向下法预备根管. 2 组均用侧压法充填根管.根据X线片情况,预备时间,器械折断、疼痛等并发症,评价根管预备和充填的疗效,1 年随访率95%.结果:A组倒敞法结合Hero 642和ProTaper机用镍钛锉预备重度弯曲后牙根管,锥度、流畅度好,术后疼痛少且程度轻,无器械折断;而B组发生器械折断3 支(P>0.05);充填恰充率、欠充率、流畅度、术后疼痛两者有显著性差异(P<0.05).结论: 倒敞法结合Hero 642和ProTaper机用镍钛锉预备重度弯曲后牙根管,成形、根充效果好,并发症少,最大限度发挥了各自优点,是预备重度弯曲后牙根管值得推广应用的有效方法.