ABSTRACT
Root canal treatment is a complex treatment with varying degrees of difficulty. Variations in the root canal shape may complicate the treatment, particularly in the biomechanical preparation stage. Ideally, biomechanical preparation should be able to maintain the shape and curvature that is similar to the original anatomy of the root canal. NiTi rotary files have higher flexibility than manual files so they may reduce iatrogenic errors such as root canal transportation. This study aims to find the differences in the effects of ProTaper Next (PTN) and ProTaper Gold (PTG) NiTi rotary files preparation toward the changes in the shape of the root canal curvature. Endodontic blocks (ISO # 15, 16mm, 2% -tapered) of 12 pieces were divided into 2 groups assigned randomly. Each endodontic block was prepared using K-file # 010, creating a glide path with ProGlider #16, then proceeding with files X1 through X2 for the PTN group, and files SX through F2 for the PTG group. Digital images of before and after root canal preparation were done using a digital camera with the same angle and distance settings. The before and after root canal preparations photos were superimposed on each other and the difference in the distance at the inner and outer root canal walls in the coronal curvature, apical curvature, and apical endpoints was measured with software. The independent t-test showed a significant difference between the transportation of the inner root canal walls that was prepared using PTN compared to PTG for each measured point (p<0.05). Observation on the outer wall measurement point showed no significant difference between the root canal wall transportation that was prepared using PTN compared to PTG at all measurement points (p> 0.05). There are differences in the preparation of the PTN and PTG rotary systems in terms of the shape of root canal curvature. PTG is a rotary system that provides the preparation results that is the closest to the shape of an original S-shaped root canal curvature.
