Apical transportation using two instrumentation techniques

Objectives:, to evaluate instrumentation using the balanced forces technique and previously bent files in simulated root canals. Methods:, twenty epoxy resin simulated root canals with a 30º curvature angle were created, filled with India ink and photographed. Group I was instrumented according to the balanced forces technique, while in Group II the files were previously bent in a 30º curve to fit the canal. Tripleflex (SybronEndo, Glendora, CA, USA) files were used in both groups, from #15 to 30. The simulated canals were again filled with India ink, photographed and the images before and after instrumentation were superimposed. Results:, statistical analysis showed significant differences (Student's t test, p<0.001) between groups, with less deformation caused by the group instrumented with previously bent files (119 ± 24.4µm) when compared to the group where balanced forces were used (439 ± 42.7µm). Conclusions:, when stainless steel files are used, the balanced forces technique produce a higher apical transportation than the technique where files are previously bent to adjust to canal curvature.