Comparison of apical transportation between ProFile™ and ProTaper™ NiTi rotary instruments

Aim To use a newly developed radiographic technique to compare apical transportation and loss of working length (WL) between .06 taper ProFile((TM)) Series 29 and ProTaper((TM)) nickel-titanium (NiTi) rotary instruments ill vitro. Methodology Mesio-buccal canals of 40 extracted mandibular molars were randomly divided into two groups. Group 1 was instrumented with ProFile((TM)) and group 2 with ProTaper((TM)) instruments according to the manufacturers' directions. A specially constructed radiographic jig with a Schick digital radiographic system (Schick Technologies Inc.. Long Island City, NY, USA) was used to take pre- and postoperative radiographs of the samples at predetermined angulations. Using AutoCAD 2000 (Autodesk Inc., San Rafael, CA. USA). the central axes of initial and final instruments were radiographically superimposed to determine the loss of WL and degree of transportation at D-0, D-1, D-2 and D-4 from the WL. Data were analysed using repeated-measures ANOVA. Results A statistically significant difference in apical transportation was found at the D4 level between the two groups (P = 0.05). There was no statistical significance regarding postinstrumentation change in WL between groups. Spearman's Bivariate Correlation analysis indicated no statistically significant relationship between the radius of curvature and transportation. Conclusion The results indicate that both ProTaper((TM)) and ProFile((TM)) instruments are comparable to each other in regards to their ability to optimally enlarge root canal with minimal transportation and loss of WL ill vitro.