Chlorhexidine-encapsulated mesoporous silica-modified dentin adhesive

This work aims to explore the feasibility of chlorhexidine-encapsulated mesoporous silica ([email protected]) as a modifier of a commercial dental adhesive via the evaluation of physicochemical properties and antibacterial capabilities of adhesive–dentin interface. Therapeutic adhesives were developed in the present study by incorporating [email protected] into a commercial adhesive at four mass fractions (0, 1, 5 and 10 wt.%). The antibacterial capability on Streptococcus mutans (S. mutans) biofilm, conversion degree, adhesive morphology, microtensile bond strength (MTBS) and nanoleakage expression were evaluated comprehensively. MTT and CLSM evaluation showed that [email protected] adhesive inhibits S. mutans biofilm growth, while CHX is released from the modified adhesive continuously. The incorporation of [email protected] did not affect immediate bond strength at the concentration of 1% and 5% (P > 0.05). Moreover, these bonds were mainly preserved in 5% [email protected] group after one month of collagenase ageing. Meanwhile, [email protected] adhesive groups exhibited similar nanoleakage distribution compared with the control. This study showed that the 5% [email protected] adhesive achieved balance amongst unaffected immediate bonding strength, well-preserved bonds against collagenase ageing and effective inhibition of S. mutans biofilm growth. [email protected] dentin adhesive can potentially extend the service life of adhesive restoration in clinic.