Abstract
This study aimed to formulate and characterize the drug-release, physicochemical, and biological properties of doxycycline (DOX)-loaded mesoporous nanosilica (MNS) within experimental resin primers and to investigate the resin-dentin interfacial structure, properties, and performance in terms of microtensile bond strength (uTBS) under different clinically simulating biodegradation/aging conditions using ex-vivo teeth models for a duration of 12 months.
MNS was formulated utilizing sol-gel method and loaded with DOX. The morphological, physicochemical, and spectral characterization of the nanocarriers was performed along with drug-release kinetics at varying pH. After incorporating DOX@MNS using two varying concentrations (0.25 wt% and 0.5 wt%) in dentin bonding agent, the modified adhesive was studied for drug-release kinetics at varying pH (7.4, 6.5 and 5.2), degree of conversion (DC), antimicrobial MTT assay, and cytotoxicity. Sectioned teeth were bonded using DOX@MNS modified bonding agent and studied for μTBS at immediate and 12 months storage time in artificial saliva.
DOX-loaded MNS showed a considerable pH-dependent drug release behavior. The greatest percentage of DOX release was seen with 0.5 wt% DOX-loaded MNS at pH 5.2. A 0.5 wt% DOX-loaded MNS-modified adhesive samples demonstrated more profound antibacterial potential against Streptococcus mutans. After 12 months in artificial saliva, the 0.25 wt% DOX-loaded MSN-modified adhesive exhibited the highest μTBS.
The incorporation of 0.5 wt% DOX-loaded MNS in dentin bonding agent yielded superior antibacterial and enhanced bond strength for dentin bonding.