(PR079) Comparative Evaluation of Lipopolysaccharides Removal from Infected Root Canals by GentleWave or Laser-activated Irrigation

Objective: Advances in technology have introduced adjuncts in the chemomechanical debridement of canals. Among these, laser-activated irrigation (LAI) and multi-sonic irrigation such as the GentleWave system (GSW) have been shown in in vitro studies to promote the disinfection of root canal systems and the removal of lipopolysaccharides (LPS), highly immunogenic constituents of the cell wall of Gram-negative. However, it is unknown if these adjuncts are effective in removing LPS from infected root canals in the clinical setting. Thus, we hypothesized that GWS promotes a greater reduction of LPS compared to needle irrigation and LAI.

Methods: To test this hypothesis, we performed a single-blinded randomized clinical trial, including patients with teeth diagnosed with pulp necrosis and symptomatic apical periodontitis who were undergoing non-surgical root canal treatment. Patients were randomized to either needle, Gentle Wave, or Laser-Assisted irrigation. The root canal systems were sampled with paper points for LPS levels pre-operatively and after irrigation with one of the standardized protocols. The concentration of LPS was determined using Limulus Assay following well-established protocols, and statistical significance was determined by one-way ANOVA with Bonferroni’s post hoc test set at p< 0.05.

Results: LPS was detected in all canals, and the chemomechanical preparation greatly reduced their levels in all groups, with the greatest removal observed in the Gentle Wave system group. Collectively, these results support the use of adjunct irrigation methods not only in the disinfection of canals but also in detoxification, resulting in the removal of antigenic molecules that could be responsible for flare-ups and persistent inflammation.