Aim: The purpose of this in-vitro study was to compare the incidence of deviation in curved canals after negotiation and glide path preparation with hand K-files, SafeSider reamers and Path files.Methodology:45 ISO #15, 0.02-tapered, curved Endo Training Blocks were used in this study. Samples were assigned to 3 different groups(n = 15). Group A: Stainless steel hand K-files; Group B: Stainless steel hand SafeSider reamers and Group C: Rotary NiTiPathFiles. Pre instrumentation image of each sample was captured with stereomicroscope. Similarly, after instrumentation, all samples in each group were repositioned in the slot of the support apparatus and post instrumentation image was captured and pre and post instrumentation images were saved as TIFF format file. These images were used to evaluate the occurrence of deviation in the canal shape. The difference between the mesial and distal sides at each measuring point in the canal was calculated. The values of these differences were subjected to statistical analysis. The data were analyzed by one way ANOVA and Tukey’s non-parametric test. Results: Intra group analysis showed that, all instruments promoted some deviation in virtually all levels. There was statistically significant difference at all levels for all groups (P < 0.01) except for the 5mm level (between Group B and C) and the 7mm level (between Group B and C). Overall, regardless of the group, more deviations were observed in the distal wall than the mesial wall. Conclusion: In conclusion, our findings suggest that rotary NiTi instruments are suitable for adequate glide path preparation because they promoted less deviation from the original canal anatomy when compared with and-operated instruments.
