Substrate‐Driven Adhesive Strategies for Durable Bonding to Coronal and Radicular Dentin Following Endodontic Procedures: A Systematic Review of In Vitro Evidence

OBJECTIVES: To evaluate substrate-directed strategies affecting the durability of adhesive bonding to coronal and radicular dentin following endodontic procedures based on in vitro evidence. MATERIALS AND METHODS: A systematic search (PubMed, Scopus, Web of Science, EMBASE) identified in vitro studies assessing bond strength to human permanent coronal or radicular dentin following documented endodontic intervention. Eligible studies evaluated radicular dentin for fiber-post bonding or coronal/pulp-chamber dentin for direct restorative bonding under artificial aging conditions. Data on dentin pretreatment, adhesive systems, resin cements, and bond strength outcomes were extracted. Risk of bias was evaluated using ROBDEMat. Due to methodological heterogeneity, a narrative synthesis was performed. RESULTS: Twenty-four studies were included (21 fiber post; 3 coronal dentin). Risk of bias was low in 42%, moderate in 54%, and high in 4% of studies. In radicular dentin, chlorhexidine (CHX), ethanol wet bonding, EDTA conditioning, and collagen cross-linkers (carbodiimide (EDC) and dimethyl sulfoxide (DMSO)) generally improved aged bond durability, particularly in cervical regions. Ultrasonic and laser-assisted activation enhanced smear layer removal and interfacial adaptation. Resin cement performance varied with substrate condition, with 10-MDP-containing systems showing superior stability. Limited coronal/pulp-chamber evidence suggested potential benefits of short-term CHX and mild chelating/acidic pretreatments, with more consistent aging performance observed for two-step self-etch approaches in selected experimental conditions. CONCLUSIONS: Bond durability following endodontic procedures is strongly substrate dependent. Stable adhesion is promoted by collagen preservation, optimized smear layer management, and chemically interactive adhesive systems. However, substantial heterogeneity among in vitro studies, together with the exclusively in vitro nature of the evidence, limits direct comparability and precludes clinical standardization. CLINICAL SIGNIFICANCE: Substrate-directed pretreatment strategies, when combined with appropriate adhesive selection, may enhance the longevity of bonded restorations following endodontic procedures by reducing degradation at the resin-dentin interface.