Dentition Type as a Determinant of Microbial Load Reduction by Antimicrobial Photodynamic Therapy in Deep Dentin Caries: A Systematic Review and Meta-analysis.

Statement of the Problem: Antimicrobial photodynamic therapy (aPDT) is a protocol proposed for reduction of bacterial load in deep dentin caries in primary and permanent dentitions. However, considering the difference in the morphology of dentinal tubules in primary and permanent teeth, the effect of this treatment may be different on the two dentition types. Purpose: This systematic review and meta-analysis aimed to assess the effect of type of dentition as a determinant of microbial load reduction by aPDT in deep dentin caries. Materials and Method: An electronic search was conducted in Scopus, Web of Science, Cochrane, Medline, and Embase databases, from the first record until April 30, 2022. After article screening by three reviewers, seven studies were included in this meta-analysis. The mean log of Streptococcus mutans (S. mutans) count, Lactobacillus spp. count, and the entire bacteria in the cavity before and after aPDT was calculated with 95% confidence interval (CI), and compared between the two groups of primary and permanent teeth by the random effect model. The I² test was applied to assess the heterogeneity of the findings. Publication bias was evaluated by visual examination of the funnel-plot symmetry. Results: Of 7 retrieved articles, analysis of 3 studies on permanent teeth showed that aPDT caused a significant reduction in total bacterial count in the cavity [SMD: 0.64, 95% CI:(0.31, 0.96), p= 0.0001), S. mutans count [SMD: 0.92, 95% CI:(0.58, 1.25), p< 0.0001], and Lactobacillus spp. [SMD:1.1, 95% CI:(0.76, 1.45), p< 0.00001)]. Analysis of the remaining 4 studies on primary teeth indicated that aPDT had a significant effect only on S. mutans count [SMD: 0.60, 95% CI:(0.23, 0.97), p= 0.001), and its effect on total bacterial count of the cavity [SMD: 0. 90, 95% CI:(-0.02, 1.82), p= 0.05] and Lactobacillus spp. [SMD: 0.18, 95% CI:(-0. 29, 0.64), p= 0.45)] was not significant. Conclusion: The results showed that aPDT could serve as an effective adjunct for reduction of microbial load in permanent teeth. [ABSTRACT FROM AUTHOR]