Effect of different retreatment file systems on the apically extruded debris during retreatment

The aim of this study to compare the amount apically extruded debris by four different retreatment file systems while root canal re-treatment. The primary goal of root canal treatment is to eliminate microorganisms and complete filling of the root canal. Sometimes root canal treatment may fail andthere are various treatment options after failure. At first, orthograde retreatment of root canal treatment should be considered. Dentin debris, and irrigants may extrude from the apical foramen to the periapical area during retreatment. It is known that different amounts of apical extrusion occur in each instrument type. In our study, 64 single rooted mandibular premolar teeth were selected. The crowns were removed and the working length was standardized. Root canals were prepared up to F4 of the ProTaper Universal file system. After chemomechanical preparation, samples were filled by lateral compaction using AH Plus sealer. An Eppendorf tube was used for each sample, each tube was weighed thrice on a precision scale, the average of all of them was recorded. Samples were fixed to the stoppers and placed on the eppendorf tubes. Afterwards, the teeth were randomly divided into 4 groups: MicroMega Remover (Coltene), Reciproc blue (VDW), Protaper Universal retreatment system (Dentsply), D Race (FKG). During retreatment procedure, 10 mL of distilled water were used until the working length was reached. Samples were kept at 70 °C for 5 days so that the liquid evaporated completely and only debris residues remained in the tube. Each eppendorf tube, in which debris accumulated, was weighed again thrice on a precision scale and the results were obtained by taking the average of the values found. All systems caused slight extrusion of debris. Apical extrusion of debris was performed at least by the Reciproc Blue file. Apical extrusion of debris was mostly achieved by the MicroMega Remover file.