Effectiveness of Six Different Endodontic Treatments to Remove Smear Layer

Signature Grand, Davie, Florida, USA

Objective. The objective of this study was to compare the effectiveness of six different endodontic treatments to remove the smear layer from the root canals of teeth. Background. The ultrasonic activation (UA) of endodontic files and use of ethylenediaminetetraacetic acid (EDTA) may help to remove the smear layer, but this is controversial and requires investigation. Methods. In order to create a smear layer, 60 human single rooted teeth were prepared with rotary instruments to an apical preparation size of 45/.06. The teeth were then divided into six groups (A-F) of ten teeth each based on their final flush: A) EDTA with F file UA and 6% Sodium hypochlorite (NaOCl). B) NaOCl with F file UA. C) Same as group A, but with #20K file UA. D) Same as group B, but with #20K file UA. E) EDTA and NaOCl were delivered with a syringe. F) Saline delivered with a syringe as the negative control. The teeth were processed for scanning electron microscopy to visualize the smear layer removal. Data were analyzed using Chi-square statistical tests at a significance of 95%. Results. We found that the most effective treatment to remove smear layer was the use of EDTA chelating agent (p < 0.0001). The treatments which used ultrasonic activation did not have less smear layer compared to the other treatment groups (p > 0.05). Conclusion. The ultrasonic activation of endodontic files is not effective in the absence of EDTA to remove the smear layer from root canal surfaces. Grants. This research was sponsored by NSU-HPD.