Are ultrasonic tips associated with final irrigation protocols effective in removing biofilms in long oval canals and dentinal tubules?

Objective: This study investigated the associations among endodontic instruments, ultrasonic tips and various final irrigation protocols for removing intracanal and intratubular biofilms in long oval canals.

Methodology: One hundred mandibular premolars inoculated with Enterococcus faecalis were divided into two groups: the control group (CG: n = 10), which received no treatment; and the test groups (n = 30), which included saline (SS), sodium hypochlorite (2.5% NaOCl) and chlorhexidine (2% CHX). The samples were prepared with Reciproc Blue 25/0.08, Flatsonic, Clearsonic and Reciproc Blue 40/0.06. Each test group was divided into three subgroups (n = 10): conventional irrigation (CI) with syringes and needles, passive ultrasonic irrigation (PUI) and continuous ultrasonic irrigation (CUI) with an Irrisonic tip. The root canals were examined using confocal laser scanning microscopy. Mann‒Whitney and Kruskal‒Wallis tests followed by Dunn post hoc tests (p < 0.05) were used for statistical analysis.

Results: NaOCl and CHX were effective for intracanal and intratubular decontamination. Saline showed significant decontamination in the intratubular areas when CUI was used. The CI method was the least effective for intracanal decontamination.

Conclusion: The use of Flatsonic and Clearsonic ultrasonic tips is promising for root canal disinfection.

Clinical Relevance: The disinfection techniques in endodontic treatment focus on the removal of biofilms from long oval canals, which is crucial for effective cleaning during root canal procedures.