“In-Vitro Evaluation of the Efficacy of PIPS Irrigation System on disinfection of Type 2 canal systems in Molars.”

Introduction: This in vitro study was designed to compare the antimicrobial effects of PIPS® laser activation of irrigant against established 3-week bacterial biofilms to traditional needle irrigation in root canal therapy. Methods: Twenty-four extracted human teeth of one common canal configuration (Vertucci Type II) were endodontically cleaned and shaped using two different preparations (flared #25/0.06 or non-flared #20/0.04). Teeth were inoculated with a 3-week plaque biofilm, disinfected with one of two irrigation protocols (NaOCl or saline), and one of two delivery methods (PIPS or needle irrigation), resulting in six teeth per group. PIPS groups were run in duplicate. During the period of biofilm formation, 0.5 ml of media was discarded and replaced with fresh culture media every 48 hours. Following the irrigation treatment, the number of viable bacteria in root canals was determined by MTT bacterial viability assay. Data was analyzed for statistical significance by ANOVA followed by Scheffe’s f-test, with a pvalue less than 0.05 considered significant. Results: All saline groups showed significantly more bacteria remaining after irrigation than the corresponding sodium hypochlorite (NaOCl) groups. PIPS 0.06 NaOCl group showed significantly greater disinfection than the needle 0.06 NaOCl group. While PIPS 0.04 NaOCl had greater disinfection than its needle group counterpart, this was not significant (p > 0.05). All other groups showed no significant differences in viable bacteria enumerated from root canals. Conclusions: The use of the PIPS laser technique with a novel irrigation protocol in an in vitro setting showed statistical significance in achieving higher disinfection in larger tapered preparations than needle irrigation. Higher disinfection (although not 2 significantly different) was found in in 0.04 tapered preparations that had undergone the PIPS technique compared to needle irrigation of 0.04 tapered preparations.