Endodontic retreatment with halothane versus chloroform solvent

Chloroform has been the most widely used solvent in endodontics, but due to concerns about its safety, alternatives have been sought. The purpose of this study was to compare the effectiveness of gutta-percha removal and time of retreatment between halothane and chloroform used as solvents. Thirty mandibular premolars were prepared, obturated, and stored in a humidor for 14 months, after which they were randomly divided into two groups for retreatment. The teeth were retreated using either halothane or chloroform as the solvent. The time of retreatment was measured to the nearest minute. Retreatment was deemed complete when there was no evidence of gutta-percha or sealer on the files or paper points. Teeth were split longitudinally and photographed. The resulting slides were projected, the canals traced, and the areas of the canal, gutta-percha, and sealer were measured using a sonic digitizer. The results were analyzed statistically by t test. The results showed no significant difference in gutta-percha removal between the two groups. The chloroform group took significantly less time to retreat than halothane (7.7 min. versus 10.8 min, respectively).