Effectiveness of ultrasonically activated irrigation on root canal disinfection: a systematic review of in vitro studies

OBJECTIVES: Reduction of microbial load from the root canal systems is a pre-requisite for healing of lesions of endodontic origin. Such microbial reduction is influenced by the method of irrigant delivery and activation. The aim of this systematic review was to compare the effect of ultrasonically activated irrigation (UAI) with other irrigation techniques on the reduction of microorganisms 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. The selected articles were assessed using methodological quality scoring protocol. The risk of bias in selected studies was critically assessed by two reviewers.

RESULTS: A total of 15 articles were included for the systematic review. The included studies were heterogeneous in study design; hence, meta-analysis was not performed. The overall risk of bias for the selected studies was moderate. Overall, UAI showed superior reduction of microbial counts, resulting in better disinfection compared to other irrigation systems chosen for comparison in this review.

CONCLUSION: The use of UAI can bring about superior microbial reduction within the root canal system compared to other irrigant activation techniques.

CLINICAL RELEVANCE: Activation of irrigants with ultrasonic brings about significant bacterial reduction from the root canal systems compared to other methods of irrigant activation and conventional syringe irrigation. This might help in improving the outcome of root canal treatment.