Effect of Rotary and Reciprocating File Systems on Root Canal Centring and Transportation: An In vitro Cone Beam Computed Tomography Study

Abstract Introduction: Root canal preparation is crucial for successful endodontic treatment. It involves cleaning and shaping the canal, but files can cause canal transportation, or the undesirable removal of dentin, especially in curved canals. This study aims to use cone beam computed tomography (CBCT) to compare the centring ability and transportation caused by two rotary (Hyflex EDM and ProTaper Next) and two reciprocating (WaveOne Gold and Reciproc Blue) file systems. Materials and Methods: 80 mesial roots from human mandibular molars were randomly assigned to two groups: Rotary and reciprocating file systems. Each group was further divided into two subgroups for specific files (ProTaper Next, Hyflex EDM, WaveOne Gold and Reciproc Blue). Pre- and post-instrumentation CBCT scans were taken to evaluate and compare canal centring and transportation at three different levels. Results: Canal centring ratio was significant bucco-lingually and mesio-distally at 5 mm and 7 mm levels between Groups 1a, 1b, 2a and 2b ( P < 0.05). Canal transportation was significant bucco-lingually at 3 mm, 5 mm and 7 mm levels between Groups 3a and 3b ( P < 0.05). However, mesio-distally, no statistically significant difference ( P > 0.05) was seen between the groups at all three levels of the root canal. Conclusion: Hyflex EDM rotary file showed better root canal centring ability and lesser canal transportation compared to ProTaper Next file, whereas WaveOne Gold reciprocating file showed better root canal centring ability, and the Reciproc Blue file showed lesser canal transportation at all three levels of root canals. However, the Hyflex EDM rotary file system showed better canal centring ability and less canal transportation compared to other file systems used.