In Vivo Efficacy of Diode Laser as a Monotherapy in Root Canal Disinfection: A Systematic Review and Meta-Analysis

Objective: The aim of this study was to conduct a systematic review and meta-analysis of the available scientific evidence to validate the use of diode laser treatment as monotherapy for disinfection of root canals during endodontic treatment. Background data: Root canal disinfection is an integral step in successful endodontic therapy. Evidence suggests better clinical outcomes when diode laser treatment is opted as compared with conventional, root canal disinfection/irrigation protocols. However, there is currently no standard protocol for the use of diode lasers in disinfection of root canals. Methods: Four electronic databases, namely PubMed, Scopus, Web of Science, and Embase, were systematically searched up to December 2020 to identify studies addressing the therapeutic efficacy of dental diode lasers in endodontic root canal disinfection as monotherapy. Two examiners assessed the eligibility and quality of relevant studies, and interobserver agreement was reached for each included study. The effect of laser treatment in reduction of bacterial growth (both aerobic and anaerobic) was studied and an appropriate forest plot was prepared. A meta-analysis of similar studies was performed by calculating the pooled weighted mean difference and 95% confidence interval using a random-effects model. Results: Six and nine articles were included in the quantitative and qualitative analyses, respectively. Although moderate to high risk of bias was detected, high heterogeneity was found among the studies. Statistically significant reduction of microorganisms was observed when diode laser treatment was used for root canal disinfection; however, a small number of reported randomized clinical trials in humans with small sample sizes and high heterogeneity provide insufficient support toward its efficacy. Conclusions: There was no concluding evidence grade for recommendation of laser monotherapy for infected root canals. This does not necessarily invalidate the effect of laser therapy, but instead underscores the need for future high-quality studies.