Effect of Dentin Biomodification on the Survival of Resin Composite Restorations: An Umbrella Review

Achieving durable adhesion of composite-resins to dentin remains a key challenge in restorative dentistry, highlighting the need for biomodification strategies. Therefore, this umbrella review aims to systematically overview dentin biomodifiers and evaluate their influence on the durability of composite-resin restorations. Literature search was conducted in PubMed, Scopus, and Web of Science up to October 2024, focusing on three concepts: dentin, biomodification, and bond strength (PROSPERO: CRD42024588804). The corrected covered area (CCA) was calculated to evaluate overlap among the included systematic reviews (SRs). Among 486 identified papers, 9 SRs were selected including 7 meta-analyses. Twenty biomodification agents were identified and classified into natural, physical and chemical agents. These agents were assessed in 51 different setups with micro-tensile bond strength used in 68.62% of them. Timing of bond strength assessments varied from immediate to a 36-months period. As natural agents, Grape Seed Extract and chitosan improved bond strength after long-term aging, while induced riboflavin improved the short and medium-term periods only. Among all categories, the most studied biomodifier was Non-Thermal Atmospheric Plasma, a physical agent, which consistently enhanced resin-dentin bonding over time. However, chemical approaches did not show promising bond strength results at some exceptions. Sodium hypochlorite (NaOCl) and hypochlorous acid both immediately decreased bond strength. Overlap among reviews was slight (CCA = 1.52 %). Various biomodifiers show promise for enhancing adhesion and durability of composite-resin restorations, with their combinations potentially offering synergistic effects. Systematically identifying and characterizing dentin biomodifiers within their limitations lays the groundwork for evidence-based frameworks that guide dentists and shape future research. At present, physical scrubbing and air abrasion are the only readily available dentin biomodification techniques. Riboflavin and chitosan show promise as effective natural and affordable agents; however, their clinical use needs regulatory approval. In contrast, NaOCl should be avoided as it compromises composite restoration’s durability.