Aim: This study was conducted to evaluate the smear layer removal efficiency of apple vinegar and EDTA when used as final rinse using scanning electron microscope (SEM) and to quantify the calcium content of intraradicular dentin after being treated with apple vinegar or EDTA using energy dispersive X-ray microanalyzer (EDX).
Materials and methods: Fifty palatal roots of extracted human permanent maxillary molars with completely formed were selected and prepared with Universal Protaper rotary files. After using each file, canals were irrigated with 2 ml of 2.6% NaOCl for 1 minute. The samples were divided into 4 groups according to the final rinse used and the application time: (10 samples each), Group I: 17% EDTA for 1 minute.Group II: Apple vinegar for 1 minute. Group III: 17% EDTA for 3 minutes.Group IV: Apple vinegar for 3 minutes.Group V: control group is divided into: GV(A), Five samples
where the root canals were irrigated with sterile saline and GV(B), Five samples were used to assess the calcium content with energy dispersive X-ray microanalyzer (EDX), where the root canals will not receive any treatment. Results: Regarding smear layer removal, at coronal and middle thirds there was no statistically significant difference in the mean scores of smear layer produced by the tested groups.At the apical third the lowest mean smear layer score was recorded in specimens treated with apple vinegar for 1 minute (Group II) with a statistical significant difference from specimens treated with 17% EDTA for 1 minute (Group I). Regarding the calcium content, the highest mean value was recorded in specimens treated with apple vinegar for 1 minute (Group II) with statistically significant difference from that recorded in specimens treated with 17% EDTA for 1 minute (Group I) and specimens treated with apple vinegar for 3 minutes (Group IV). Conclusion: Apple vinegar was capable of adequately removing smear layer from intraradicular dentin when used as final rinse.Apple vinegar was more effective in removing smear layer from intraradicular dentin at the apical third
compared to 17% EDTA. Apple vinegar was more effective when used for one minute as final rinse in the removal of smear layer without affecting the calcium content of intraradicular dentin compared to 17% EDTA.