Evaluation of Efficiency of three NiTi Instruments in Removing Gutta Flow 2 from Root Canal during Re-treatment – An in vitro Study

To evaluate the efficiency of three rotary nickel titanium instruments and hand instrumentation in removing gutta flow 2 from root canals.

60 extracted human maxillary central and lateral incisors were instrumented with k-files and filled with guttaflow 2. The teeth were randomly divided into four experimental groups of 15 specimens each. Removal of gutta flow 2 was performed with the following devices and techniques: protaper Universal rotary retreatment system, R-Endo retreatment files, Mwo retreatment files and Hedstrom files. Time to reach working length and to eliminate filling material was also recorded. The specimens were rendered transparent for evaluation of the area of the remaining gutta flow 2 under stereomicroscope at 6x magnification. Photographs were taken for further analysis using computer image analysis program. The results were statistically analysed using ANOVA and Bonferroni test.

The Protaper Universal retreatment system resulted in a smaller percentage of canal area covered by residual gutta flow 2 than in other groups, but a significant difference was found between Protaper and Mtwo group and between protaper and Hedstrom group(p< 0.001). The mean operating time was minimum with Mtwo group (5.08±0.06 min) while it was found to be maximum with hand files (7.93± 1.03 min).

It was concluded that all test techniques left gutta flow 2 with in the root canal. The Pro Taper Universal rotary retreatment system proved to be an efficient method of removing guttaflow 2 from maxillarycentral and lateral incisors.