In vivo Comparison of Surface Changes between Two Nickel Titanium Rotary Single File Systems after Instrumentation in Moderately Curved Root Canals

Aim: To compare post instrumentation surface changes between Two Nickel-Titanium Single Rotary systems (FKG XP Endo Shaper, FKG Dentaire, La Chaux-de-Fonds, Switzerland and Micromega One Curve, Micro Mega, Besancon, France using Stereomicroscope.

Materials and Methods: 40 patients requiring endodontic treatment and satisfying the inclusion criteria for the study were included and randomly divided into 4 groups having 10 patients each. Group 1: Instrumentation of root canal in 10 patients was done using FKG Endo Shaper for 15 seconds. Group 2: Instrumentation of root canal in 10 patients using FKG Endo Shaper for 30 seconds Group 3: Instrumentation of root canal in 10 patients using Micromega One Curve for 15 seconds .Group 4: Instrumentation of root canal in 10 patients using Micromega One Curve for 30seconds. After instrumentation for specified time all the files were examined at the apical and middle third under the Stereomicroscope (Labomed, Inc, United States) at 40X magnification for the presence of any surface changes( defects/ deformity). Scoring of defects was assigned to each file according to the degree of damage. Results were statistically analysed using Kruskal Wallis test and Mann Whitney Post hoc test and were used to compare the median microscopic scores between different groups at Apical and Middle 3rd region. The level of significance was set at P<0.05.

Results: Comparison of microscopic scoring between both the file groups at apical and middle third region using Kruskal Wallis Test revealed that a statistically significant difference was observed in the apical region with p value <o.o2, No statistical significant difference was found in the middle third region, suggesting that the apical region showed more surface changes than the middle third region. Comparison of scores between groups at the apical region using Mann Whitney Post hoc test revealed that there was statistically significant difference in Group 1 compared with group 2, group 3 and group 4 whereas, there was no statistical significant difference between other groups. Comparison of microscopic scoring between Apical and Middle region in each group using Wilcoxon Signed Rank Test revealed that a statistically significant difference was found in the middle third region of Group 4 with P value P<0.03.

Conclusion: It was concluded that More surface changes were seen in FKG XP Endo Shaper file than Micromega One curve. Apical regions showed more changes compared to the middle third region and there was statistically significant difference between groups 1 ,2 and 3. None of the instruments fractured during instrumentation.