Georgelin-Gurgel M, Devillard R, Lauret M E, Diemer F, Calas P, Hennequin M
Université Paul Sabatier, CH Purpan, Toulouse, France.
Odontostomatol Trop. 2008 Mar;31(121):5-11.
This study set out to evaluate the prevalence of iatrogenic events during preclinical teaching of endodontics, comparing manual stainless steel versus nickel-titanium (Ni-Ti) rotary techniques for shaping natural root canals.
Two groups of 13 inexperienced dental students were randomly made up and asked to shape 104 canals in natural teeth. Group R used Ni-Ti rotary files for shaping while Group M used a sequence of five manual stainless steel files. Occurrence of file breakage, loss of work length, and iatrogenic instrumentation on apical foramina were evaluated.
Overall occurrence of adverse events during shaping did not differ between the groups, being 58% in Group R and 51% in Group M. Inter-group distribution of type of event differed significantly, however. File breakage (7.7%) and loss of working length of > 2 mm (6.7%) occurred only in Group R. Iatrogenic shaping on apical foramina showed the same frequency in each group.
Manual instrumentation is safer than rotary instrumentation in the hands of inexperienced students. Acquiring skill in the use of Ni-Ti rotary instrumentation requires specific preclinical training to avert file breakage. These findings argue for the rethinking of theoretical and practical coursework in endodontics teaching, especially in dentistry schools where students are required to treat patients during their training.
本研究旨在评估牙髓病学临床前教学期间医源性事件的发生率，比较手动不锈钢器械与镍钛（Ni-Ti）旋转器械预备天然根管的情况。
随机将两组各13名缺乏经验的牙科学生分组，要求他们预备104颗天然牙的根管。R组使用Ni-Ti旋转锉进行预备，而M组使用一套五支手动不锈钢锉。评估锉折断、工作长度丧失以及根尖孔医源性预备情况的发生情况。
两组在预备过程中不良事件的总体发生率无差异，R组为58%，M组为51%。然而，组间事件类型的分布存在显著差异。锉折断（7.7%）和工作长度丧失超过2mm（6.7%）仅发生在R组。每组根尖孔医源性预备的发生率相同。
在缺乏经验的学生操作中，手动器械预备比旋转器械预备更安全。掌握Ni-Ti旋转器械的使用技能需要特定的临床前培训以避免锉折断。这些发现促使人们重新思考牙髓病学教学中的理论和实践课程，尤其是在那些要求学生在培训期间治疗患者的牙科学院。
