Comparative Evaluation of Three Solvents Used in Endodontic Retreatment: A Scanning Electron Microscope Study

Non-surgical endodontic re-treatment is an attempt to re-establish healthy periapical tissues after inefficient treatment or re-infection of an obturated root canal system. Re-treatment requires the removal of defective root canal filling. The removal of gutta percha can be done with several techniques which include rotary files, ultrasonic instruments and hand files in combination with heat or chemicals. The objective of this study was to compare the efficacy of three solvents on the removal of root canal filling materials from the dentinal tubules during endodontic re-treatment. Forty single rooted teeth were selected for the study. After cleaning and shaping, the samples were obturated with gutta percha and a resin based sealer. They were stored for three months before being randomly divided into four groups: Eucalyptol (n=10), D-Solve (n=10), Canalsolve R (n=10) and Control (n=10). Re-treatment was done using the solvents and hand files. Following re-treatment the teeth were split longitudinally for SEM evaluation and the number of dentinal tubules free of obturating material in the middle and apical third was recorded. A significantly higher number of dentinal tubules were found to be free of obturating material in the eucalyptol group as compared to the other groups. Under the tested conditions it may be concluded that eucalyptol may be considered as a more efficient solvent as compared to D-Solve and Canalsolve R.