Comparative evaluation of the antimicrobial efficacy of nanoparticle-mediated photodynamic therapy versus photodynamic therapy and conventional disinfection in endodontics: A systematic review and meta-analysis

Introduction: The aim of this systematic review was to assess the antimicrobial activity of nanoparticle-mediated photodynamic therapy (N-PDT) on Enterococcus faecalis biofilms in the presence of dentin substrate when compared to photodynamic therapy (PDT) and conventional disinfection protocols.

Materials and methods: This systematic review was registered in Open Science Framework (10.17605/OSF.IO/GBR3F). Six databases, namely PubMed, Embase, Web of Science, Scopus, Medline, and Google Scholar, were searched for English language articles until June 2022. Laboratory studies assessing the antimicrobial activity of N-PDT against E. faecalis biofilm in human or bovine teeth were included. The risk of bias (RoB) was evaluated using the Joanna Briggs Institute tool for quasi-experimental studies. Meta-analysis was performed using the random-effects maximum likelihood model.

Results: The search revealed 2804 articles, out of which 9 studies were included in the final review. Seven articles had low RoB and two had moderate RoB. Chitosan and diode laser at 810 nm were the most commonly used nanoparticle and light source, respectively. The meta-analysis of bacterial reduction log and percentage reduction revealed that N-PDT had better antimicrobial efficacy than the control group. When the bacterial reduction log of N-PDT was compared with PDT, PDT performed better N-PDT, and for percentage reduction, there was no difference.

Conclusion: The currently available evidence is low and inconclusive with regard to the superior efficacy of N-PDT. The type of nanoparticle, incubation time, light source, and exposure time were found to be covariates that influence the antimicrobial efficacy of N-PDT.