Effectiveness of Four Rotary Retreatment Instruments During Root Canal Retreatment

İngilizce (OpenAlex)

Objectives: The purpose of this in-vitro study was to investigate the residual root canal filling material after retreatment of root canals using stainless steel hand files, and four nickeltitanium retreatment instruments.Materials and Methods: Seventy five extracted mandibular premolars were instrumented and filled.The samples were randomly divided into 5 groups (n=15) and retreated using Hedström files, Mtwo R, R-Endo, ProTaper Universal Retreatment, and D-RaCe systems.The roots were digitally radiographed, then grooved split longitudinally to investigate the area of remaining filling material.The time of retreatment and the instruments fracture were also recorded. Results:The Hedström files left less filling material than the rotary retreatment instruments but a significant difference was found only in the middle third (p< 0.01).The apical third had the most residual gutta-percha and sealer compared to the coronal and middle thirds.The retreatment time for the D-RaCe and ProTaper Universal Retreatment groups were significantly shorter than other groups (p< 0.01).Eight Mtwo R files, 2 ProTaper Universal Retreatment files and 1 R-Endo file were fractured.Conclusions: All groups left residual root canal filling material inside the root canal walls.Nickel-titanium rotary retreatment instruments were faster than Hedström files but had a higher risk of instruments fracture.