23例恒牙根管机械预备断针的原因分析和处理

A causational analysis and management of 23 cases of rotary instrument breakages during dental root canal preparation with crown-down technique

目的 :近年来 ,临床上通过镍钛机用根管器械 ,采用逐步深入法进行患牙根管预备的病例越来越多 ,导致根管内断针的病例也在逐渐增多 ,对这类断针原因进行分析以减少并发症的发生。方法 :针对 2 3例近两年来采用Step -down或Crown -down技术进行机械根管预备后所出现的根管内断针进行分析和根管再处理。结果 :断针位于根管上、中、下的比率为 4∶12∶7,原因包括 :①未按操作规程。②操作的方法不当。③忽视手动器械的作用。④根管冲洗不到位。⑤使用的器械不当。经过处理后 ,大部分病例通过取出断针或建立旁路的方法完成治疗。结论 :不当操作还可导致根管内产生台阶、穿孔或折裂 ,同时 ,金属疲劳和扭矩是影响器械寿命的重要因素。通过合理操作 ,综合运用机械法、手动法甚至超声法的根管预备技术 。

AIM:The growing use of engine-driven instruments especially NiTi rotary apparatus in endodontic practice could increase the cases of failures after dental root treatment. To clarify the cause of instrument breakages could minimize the incidence of the failure.METHODS:Total of 23 cases of rotary instrument breakages in root canal preparation with crown-down or step-down technique in last two years were reported. The cause of the failure of the instrument breakage during root canal preparation and the offset management were also discussed. RESULTS: The instrument breakage complication could be leaded under following incorrect managements:①do not handled the root canal in terms of the operating instruction;②improper operational approach;③neglect the importance of hand canal instrument;④insufficient irrigation of the root canal during the operation;⑤unsuitable rotary instruments we used in a crown-down approach. After offset management, most of the cases could be successfully retreated by either extracted the breakage instruments or established bypass in the root canal.CONCLUSION:Unsuitable process could lead to form ledge, perforation and stripping of the canal. Also,metal fatigue and variable of torsional loading were two important factors in instrument fracture. With awareness of the appropriate manipulation and special attention to the equipment used and applied, integrated with hand or ultrasonic endodontic instruments, NiTi systems are safe with minimal incidence of instrumental failure.