Exploring the role of flavonoids in caries-affected dentin adhesion: A comprehensive scoping review.

OBJECTIVES: The aim of this scoping review was to evaluate the available scientific evidence regarding the use of flavonoids in the treatment of caries-affected dentin focusing on bonding to dentin. METHODS: A comprehensive literature search was performed in five databases from March 2022 and updated in April 2023: PubMed, EMBASE, Scopus, Web of Science, and Scielo. Additionally, the references of included studies were manually searched. Gray literature was excluded from the review. STUDY SELECTION: Inclusion criteria included in vitro, in situ, and in vivo studies (animal or human) published in English. Abstracts, reviews, case reports, book chapters, doctoral dissertations, guidelines, and studies using pure plant extracts were excluded. Data collected from the selected studies were summarized and subjected to narrative and descriptive analysis. Out of the 91 studies identified, only 16 studies met the inclusion criteria. RESULTS: The review analyzed eight different flavonoids (hesperidin, galardin, proanthocyanidin, genipin, quercetin, naringin, epigallocatechin-3-gallate, and other catechins subtypes) used as pretreatment or loaded into adhesive systems, primers, and phosphoric acid. The use of flavonoids improved the mechanical properties of the materials and modified the biological properties of the dentin, reducing collagen loss by the inhibition of proteolytic activity of matrix metalloproteinases (MMPs). CONCLUSIONS: Based on the findings of this scoping review, it can be concluded that the use of flavonoids as pretreatment or incorporation into dental materials preserves collagen in the hybrid layer, inhibiting the MMPs activities, modifying the collagen fibrils of the dentin matrix and improving the mechanical properties of the dental adhesive systems. Therefore, it represents a promising approach for promoting dentin biomodification. This can result in more stable bonding of adhesive restorations to caries-affected dentin.

Antibacterial activity against cariogenic bacteria and cytotoxic and genotoxic potential of Anacardium occidentale L. and Anadenanthera macrocarpa (Benth.) Brenan extracts.

OBJECTIVES: The present study aimed to assess the antibacterial activity against bacteria with cariogenic relevance, toxic and genotoxic potential of the plants Anacardium occidentale L. and Anadenanthera macrocarpa (Benth.) Bernam. DESIGN: Using a microdilution technique, the extracts were submitted to minimum inhibitory concentration (MIC) testing against Streptococcus mitis (ATCC 903), Streptococcus mutans (ATCC 25175), Streptococcus oralis (ATCC 10557), Streptococcus salivarius (ATCC 7073), Streptococcus sanguinis (ATCC 15300) and Streptococcus sobrinus (ATCC 27609). The toxicity of the extracts was then verified against eukaryotic cells. Additionally, a micronucleus assay was performed to investigate the potential mutagenic effects of the extracts on rat erythrocytes. The Student's t-test, Bonferroni test, and one-way ANOVA followed by Tukey's tests were used for statistical analysis, at a significance level of 5%. RESULTS: While the A. occidentale extract was able to inhibit all of the tested strains, with S. mutans and S. mitis being the most susceptible to that extract́s action, the A. macrocarpa did not show antimicrobial activity. Interestingly, the hemolytic, oxidant and antioxidant activities were slightly observed for either extract, even at high concentrations (1000mg/mL). The micronucleus assay showed no significant changes in the cells exposed to the extracts. CONCLUSION: The A. occidentale extract has potential as an antimicrobial agent with low eukaryotic cell toxicity or mutagenic activity. The A. macrocarpa extract, although absent of antibacterial activity might as well be a safe and effective phytotherapeutic alternative.