Decontamination of root canals infected with reciprocating instruments, sodium hypochlorite 2.5% and apple vinegar

Abstract

Objective: To evaluate decontamination of root canals infected with reciprocating instruments, 2.5% sodium hypochlorite and apple vinegar. Methods: A total of 50 single- rooted human teeth were emptied and contaminated with Enterococcus faecalis for 60 days. After the period of contamination, root canal preparation was performed with instruments, including: 1. WaveOne TM 40.08 (n = 10); 2. Reciproc TM 40.06 (n = 10); and 3. Unicone TM 40.06 (n = 10). Two control groups were used: positive control (n = 10) and negative control (n = 10). Half of the samples from each group were irrigated with 2.5% sodium hypochlorite, while another half was irrigated with apple cider vinegar. Subsequently, sterilized paper cup collections were made and immersed in culture medium with 7 mL of Lethen Broth and incubated at 37 °C for 48 hours in a reduced oxygen atmosphere. Bacterial growth was analyzed by turbidity of culture medium and UV spectrophotometry. Cleaning of dentine walls was analyzed by scanning electron microscopy. Results: All groups showed reduction of optical density of the culture medium after root canal preparation (p < 0.05). No sanitation strategy promoted complete elimination of the biological indicator. Complete removal of debris occurred in none of the groups, and no significant differences were found regardless of the thirds analyzed (p > 0.05). Conclusion: Tested reciprocating instruments and irrigating solutions reduced bacterial contamination of root canals infected with E. faecalis.