Coelho Marcelo Santos, Card Steven John, Tawil Peter Zahi
Dr. Coelho is Visiting Scholar, Department of Endodontics, School of Dentistry, University of North Carolina at Chapel Hill and Assistant Professor, Department of Endodontics, Universidade Paulista in Sorocaba, SP, Brazil; Dr. Card is Clinical Assistant Professor, Department of Endodontics, School of Dentistry, University of North Carolina at Chapel Hill; and Dr. Tawil is Director of Graduate Program, Department of Endodontics, School of Dentistry, University of North Carolina at Chapel Hill.
J Dent Educ. 2017 Mar;81(3):333-339.
The aim of this study was to retrospectively assess the safety potential of a hybrid technique combining nickel-titanium (NiTi) reciprocating and rotary instruments by third- and fourth-year dental students in the predoctoral endodontics clinic at one U.S. dental school. For the study, 3,194 root canal treatments performed by 317 dental students from 2012 through 2015 were evaluated for incidence of ledge creation and instrument separation. The hybrid reciprocating and rotary technique (RRT) consisted of a glide path creation with stainless steel hand files up to size 15/02, a crown down preparation with a NiTi reciprocating instrument, and an apical preparation with NiTi rotary instruments. The control was a traditional rotary and hand technique (RHT) that consisted of the same glide path procedure followed by a crown down preparation with NiTi rotary instruments and an apical preparation with NiTi hand instruments. The results showed that the RHT technique presented a rate of ledge creation of 1.4% per root and the RRT technique was 0.5% per root (p<0.05). Three stainless steel hand files separated: two in the RHT group and one in the RRT group. There was no separation of any NiTi file in any of the techniques. The use of the reciprocating and rotary technique for root canal instrumentation by these dental students provided good safety. This hybrid technique offered a low rate of ledge creation along with no NiTi instrument separation.
本研究的目的是回顾性评估美国一所牙科学院的博士前牙髓病诊所中，三、四年级牙科学生使用镍钛（NiTi）往复式和旋转式器械相结合的混合技术的安全潜力。在该研究中，对2012年至2015年期间317名牙科学生进行的3194例根管治疗的台阶形成和器械分离发生率进行了评估。混合往复旋转技术（RRT）包括先用不锈钢手动锉预备至15/02号建立引导通路，然后用NiTi往复式器械进行冠向下预备，最后用NiTi旋转式器械进行根尖预备。对照组为传统的旋转和手动技术（RHT），包括相同的引导通路步骤，随后用NiTi旋转式器械进行冠向下预备，并用NiTi手动器械进行根尖预备。结果显示，RHT技术的台阶形成率为每根1.4%，RRT技术为每根0.5%（p<0.05）。有三根不锈钢手动锉分离：两根在RHT组，一根在RRT组。在任何技术中，没有任何NiTi锉分离。这些牙科学生使用往复旋转技术进行根管预备具有良好的安全性。这种混合技术台阶形成率低，且没有NiTi器械分离。
