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.