The Effect of Combined Passive Ultrasonic Irrigation and XP–ENDO Finisher on Bacterial Biofilm: a comparative study

Abstract

The aim of endodontic treatment is to completely eliminate pulp tissue, debris, micro-organisms and their by-products. Mechanical preparation is of great importance to clean the apical part of root canal system; but is not enough for complete disinfection. Thus, chemical irrigation must be done to complement instrumentation of root canal system. Most commonly used irrigation technique is passive syringe irrigation which showed many drawbacks that compromised chemical disinfectant to reach different parts of root canal system as fins, isthmuses, lateral canals and apical thirds of root canals. So, dynamic irrigation techniques either manual or machine assisted were developed to overcome these drawbacks and enhance chemical effect of solutions. One of these techniques is the PUI using ultrasonic tips mounted to an ultrasonic device to introduce vibrations in the chemical within the root canal to enhance its’ penetration. Another technique is using the XP-ENDO Finisher which is a non-cutting file that is mounted on to an endodontic motor to induce cavitation and acoustic streaming in the irrigant. Many studies proved that both PUI and XP-ENDO Finisher have better disinfection results when compared to conventional passive irrigation. The aim of the study was to evaluate the effect of combining two agitation techniques (PUI and XPF) on bacterial biofilm in comparison to passive syringe irrigation and to each technique separately. Teeth samples were collected, prepared and autoclaved at 121oC for 20 minutes. Samples were inoculated with E. faecalis for 4 weeks and the divided into four experimental groups according to activation technique of irrigant. After treatment samples were split and analyzed using CLSM to detect the ratio of dead to live bacteria. Positive controls to confirm presence of live E. faecalis and negative controls to confirm absence of bacteria. This study concluded that complete eradication of bacterial biofilm is very difficult if not possible no matter the agitation techniques and irrigant used. All techniques showed better results than passive syringe irrigation although there was no statistically significant difference between PUI, XPF and combination of both in terms of bacterial reduction. PUI showed the best bacterial reduction. Further combination with other irrigation techniques may show better effect and enhance treatment outcomes.