Evaluation of Smear Layer Removal using Different Irrigant Activation Methods (Passive Ultrasonic Irrigation and Conventional Syringe Irrigation) - A Systematic Review

Abstract

Background and Aim:  Removal of smear layer and reduction in bacterial load from the root canal systems is an essential part in the success of endodontic therapy. Mechanical instrumentation alone may not be sufficient to remove this biofilm from the root canal, owing to the canal anatomy and other challenges. Adjunctive use of irrigants with conventional or passive ultrasonic irrigation system is a method to overcome this aspect. Thus, the aim of this systematic review was to compare the effect of conventional irrigation with that of passive ultrasonically activated irrigation (PUI) on the reduction of microorganisms and removal of smear layer during root canal disinfection.

Materials and Methods: The research question was created based on the PICO strategy. Two reviewers independently performed a comprehensive literature search in electronic databases. Following application of inclusion and exclusion criteria to the selected articles, a systematic data extraction sheet was constructed. Based on the area of interest the articles were included in the study.

Results: A total of 13 articles were included for the systematic review. The included studies were heterogeneous in study design; hence, meta-analysis was not performed. There was superior reduction of microbial reduction which resulted in better disinfection with passive ultrasonic irrigation system was seen compare to the conventional system.

Conclusion: The use of PUI has shown to be having superior microbial reduction and better smear layer removal than the conventional irrigation in the root canal disinfection was seen.

Clinical relevance: The study report will help in better utilisation of passive ultrasonic irrigation system along with the mechanical instrumentation for the better success of root canal therapy.