Comparison of Canal Preparation Pattern of K3 and ProTaper Rotary Files in Curved Resin Blocks

Canal shaping is a critical step of endodontic treatment. Numerous studies have shown that nickel-titanium rotary instruments can effectively produce a well-tapered root canal sufficient for obturation with the minimal risk of transporting the original canal. The purpose of this study was to compare canal preparation pattern of K3 and ProTaper rotary files in curved Resin blocks. 24 resin blocks were used in this experimental study and randomly divided into two groups of 12 blocks. Their initial images were scanned and canal preparation was done according to manufacturer's guideline. After preparation; their images were scanned in the previous position. Pre and post preparation images were superimposed by Photoshop software and the amount of resin removal was measured in 5 different zones, then analyzed statistically by ANOVA and T.Test. There was no statistically significant difference between K3 and ProTaper except on outer wall around the orifice (p>0.05). There was significantly more removal of outer wall than inner wall in both systems at this point (p<0.0001). There was no significant difference at the halfway between orifice and the beginning of the curve (p>0.05). At this zone resin removal in these systems was more on inner wall than outer wall (P>0.05). At the beginning of the curve there was significant difference in resin removal on inner wall (p<0.0001). At the apex of the curvature both systems removed remarkably more resin at outer wall but this difference was significant just for ProTaper group. There was no significant difference at the end of curvature. For both systems Resin removal was monotonous at this zone. Canal preparation pattern was overall positive for both systems except at the beginning of the curve.