Investigation of the effect of solvent use on dentin crack formation in retreatment procedures

Objectives: The aim of this study was to evaluate the effect of solvent use on crack formation in dentin structure during root canal retreatment with micro-CT. Materials and Methods: Root canal treatments were performed on the mesial roots of 20 mandibular molars. The teeth were divided in two groups: solvent useds and non-solvent. During treatment, canal preparations was performed using Revo-S files. The root canals were filled by using the lateral compaction technique. During retreatments, Protaper Retreatment files were used in both groups. Guttasolv was used during retreatment in one group. Before and after the initial treatment and retreatment, the teeth were imaged using micro-CT. In addition, the time between the beginning and the end of the procedure was measured. Results: Crack formation was not observed in either group. Residual filling material remained in the root canal after the procedure in all samples in both groups. In both groups, no statistical significant difference was found in terms of residual matter between the regions according to the results of the measurements made separately in three regions as coronal, middle, and apical regions. The working time was longer in the solvent group. Conclusions: In conclusion, within the limitations of this in vitro study, it could be said that Ni-Ti systems do not cause dentin defects if used with or without a solvent. Even if the retreatment was performed close to ideal, it was determined that residual filling material remained on the canal walls during retreatment. Clinical Relevance: Using solvent does not decrease the dentin crack formation. Keywords: Retreatment, dentinal crack, solvent, micro-ct