Multifunctional strontium-MOFs-based dental adhesive: Innovation for enhanced bonding performance and bioactivity

Abstract

Dental adhesives are primarily designed for durable adhesion between restorative materials and tooth structures. In addition to their bonding function, formulations increasingly incorporate bioactive fillers that promote remineralization, prevent secondary caries, and prolong the longevity of restorations. In this in vitro study, a novel bioactive dental adhesive was developed using strontium-based metal-organic frameworks (Sr-MOFs) with fumarate ligands as functional nanofillers. The incorporation of 0.5 wt% Sr-MOFs significantly improved the micro-tensile bond strength to 27.04 ± 6.53 MPa (p < 0.05) compared to the control, while maintaining its performance after 6 months of aging. Nanoleakage assessments confirmed superior sealing and reduced silver nitrate penetration, attributed to the nano-sized Sr-MOFs and chemical interaction between the fumarate's carboxylate groups and calcium in dentin. The adhesive also demonstrated remineralization capabilities through the deposition of apatite-like minerals when immersed in SBF. Additionally, non-cytotoxic behavior was observed, with cell viability exceeding 70 % under ISO 10993 guidelines. These findings highlight Sr-MOFs with fumarate as a promising filler for dental adhesives, supporting durable bonding and mineral regeneration for long-term restoration success. Further in vivo validation is required to demonstrate the clinical significance and practical application of these findings.