Epigallocatechin-3-gallate/nanohydroxyapatite platform delivery approach to adhesive-dentin interface stability

Current adhesive techniques allow clinicians to bond composite resin to dentin for esthetic restoration of defected tooth. However, a vulnerable adhesive-dentin interface remains clinically challenging resulting in frequent replacement of the restorations. The inappropriate management of exposed dentin plays a major role in jeopardizing the bond stability of the adhesive-dentin interface. To overcome this problem, this paper highlights an epigallocatechin-3-gallate/nanohydroxyapatite (EGCG/nHAp) platform (mesoporous silica-based) delivery approach to the adhesive-dentin interface and investigates its effectiveness on dentin bonding durability. Microtensile bond strength, interfacial nanoleakage, and in situ zymography were determined. The inhibition of Streptococcus mutans ( S. mutans ) biofilm formation along the adhesive-dentin interface was assessed by confocal-laser scanning microscopy, colony forming units counts, and field-emission scanning electron microscopy. Results revealed that applying the EGCG/nHAp delivery platform on exposed dentin could preserve the dentin bond strength and reduce interfacial nanoleakage after collagenase ageing; moreover, it could inactivate the activity of matrix metalloproteinase within the hybrid layer and inhibit the adhesion and biofilm formation of S. mutans . The proposed approach demonstrates great potential for stabilizing the adhesive-dentin interface to improve dentin bonding durability and prevent secondary caries progression, thereby indicating a promising strategy to prolong the service life of dental restorations.