微创医学

目的通过体外实验探讨不同转速及操作者对Hero 642机用镍钛锉使用后出现变形或折断的影响。方法实验分两大组。A组的两个亚组由同一位技术熟练的操作者分别使用两种不同减数比的根管治疗手机进行根管预备;B组的三个亚组均使用同一减数比的根管治疗手机,分别由经验不同的三名操作者完成根管预备。每个亚组中有100个人类离体牙根管,每只Hero 642机用镍钛锉最多预备10个根管。比较亚组之间变形、折断的器械数目。结果 A组中均未出现器械变形和折断;B组中变形和折断的器械分别为13支和6支,经验丰富的操作者使用的器械未出现折断;第五亚组中器械变形率和折断率与第三、第四亚组相比较均有显著性差异。结论对于有丰富经验的操作者,转速增加至300 rpm不会引起器械折断,临床操作经验的积累对减少器械折断是重要的影响因素。

Objec廿ve To evaluate the influence of rotational speed and opemtor~proficiency with a specific nickel-titanium rotary instrumentation technique on the incidence of deformation and separation of instruments．Meth— ods The study WaS designed as two parts_,Group A Was divided into 2 subgroups(Group 1 and Group 2，in which one proficient operatorfinished canal preparation tll diferent mtmional speeds)，and Group B Was divided into 3 subgroups(Group 3，Group4，andGroup5，inwhichthe canalswere preparedwiththe same rational speed but by operators with varying proficiency)．AⅡsubgroups were due to finish 100 canals and each Hero 642 to prepare 10 canals at most．Numbers ofinstrument deformation and separation of each sub group were compared．Results In Group A， instrument deformation and separation did not occur．In Group B，13 and 6 instruments were deform ed and separated ， but none ofthese occurred in the subgroup operated by proficient operator．Them existed a significan t diference between Group 5(the least experienced operator)and other twO groups(Group 3 and Group 4)with respect to instmmerit deformation and separation．Conclusion Operation experience accumulation is crucial to prevent instrument separation and reduce the incidence of deformation．Rotational speed as hish as 300 rpm is still safe with the expefi— enced operator