The aim of this study was to perform a systematic review of the literature followed by a meta-analysis about the efficacy of photodynamic therapy (PDT) on the microorganisms responsible for dental caries. The research question and the keywords were constructed according to the PICO strategy. The article search was done in Embase, Lilacs, Scielo, Medline, Scopus, Cochrane Library, Web of Science, Science Direct, and Pubmed databases. Randomized clinical trials and in vitro studies were selected in the review. The study was conducted according the PRISMA guideline for systematic review. A total of 34 articles were included in the qualitative analysis and four articles were divided into two subgroups to perform the meta-analysis. Few studies have achieved an effective microbial reduction in microorganisms associated with the pathogenesis of dental caries. The results highlight that there is no consensus about the study protocols for PDT against cariogenic microorganisms, although the results showed the PDT could be a good alternative for the treatment of dental caries.

Background: COVID‐19 is an infectious disease caused by SARS‐CoV‐2 associated with haematological manifestations (thrombolytic events).Aims: Considering the high prevalence of the thrombotic scenarios associated with COVID‐19, the aim of this study was to perform a systematic review of the available literature, concerning the relation of COVID‐19 and the thrombotic events, and identify prognostic factors for these events.Materials & Methods: PubMed, Web of Science and Scopus databases were searched. Independent reviewers conducted all flow diagram steps. For qualitative analysis, Oxford level of evidence and Newcastle‐Ottawa scale were used in the eligible articles. For the prognostic factors, a meta‐analysis was conducted to age, number of neutrophils and platelets, and levels of ferritin, C‐reactive protein, lactate dehydrogenase and D‐dimer. Publication bias was accessed by funnel plot and by trim‐and‐fill test. Trim‐and‐fill test was also applied to evaluate meta‐analysis bias.Results: Twenty articles were included in the qualitative analysis, and 6 articles were included in the meta‐analysis. Case‐control studies showed bias related to exposure, and the main bias in cohort studies were related to selection and outcome. All articles received score 4 for the level of evidence. Hypertension and diabetes were the comorbidities more frequently associated with thrombolytic events. Significant results were found regarding D‐dimer (P < .0001) and age (P = .0202) for thrombotic events in patients diagnosed with COVID‐19.Conclusion: Patients older than 60 years, with hypertension, diabetes and D‐Dimer values above 3.17 µg/mL, can be considered prognostic factors for developing thrombotic events due to COVID‐19.