Effect of grape seed extract on stability of restorations with composites resin: A systematic review and meta-analysis

Grape Seed Extract (GSE), rich in proanthocyanidins (PAC), has been extensively researched to optimize the stability of the hybrid layer in dentin substrate. Therefore, this study aims to evaluate the use of grape seed extract in the stability of restorations with resinous composites in dentin, by a review and meta-analysis. The search was carried out in 4 different databases: Online Medical Literature Search and Analysis System (Medline – PubMed), Web of Science, Science Direct, and Scopus. Proanthocyanidins, Cross-Linking Reagents, and Dentin descriptors were used with their respective entry terms connected by the boolean operators AND and OR. We found 1074 articles, which, after applying the PRISMA flowchart checklist, resulted in 9 articles selected according to the eligibility criteria. We tabulated the qualitative results and assessed the risk of bias in each of them. Of the selected articles, 2 presented low risk, 5 medium risk and 2 high risk of bias. We compiled and tabulated the numerical data of bond strength to perform the meta-analysis (p < 0.05) of the articles that presented the GSE as a pretreatment and incorporated into the conditioning agent. We noted that, as a pre-treatment, the GSE improves the bonding stability, but incorporated with phosphoric acid it decreases the stability when compared to the control group.