Long-term antibacterial activity and cytocompatibility of novel low-shrinkage-stress, remineralizing composites.

Affiliation

Bhadila G(1)(2)(3), Menon D(4), Wang X(5), Vila T(4), Melo MAS(6), Montaner S(4)(7), Arola DD(8), Weir MD(2), Sun J(5), Hockin H K, Xu(2)(7)(9).
Author information:
(1)Ph.D. Program in Dental Biomedical Sciences, Biomaterials and Tissue Engineering Division, University of Maryland School of Dentistry, Baltimore, MD, USA.
(2)Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD, USA.
(3)Department of Pediatric Dentistry, Faculty of Dentistry, King AbdulAziz University, Jeddah, Saudi Arabia.
(4)Department of Oncology and Diagnostic Sciences, University of Maryland School of Dentistry, Baltimore, MD, USA.
(5)Volpe Research Center, American Dental Association Foundation, Frederick, MD, USA.
(6)Division of Operative Dentistry, Department of General Dentistry, University of Maryland School of Dentistry, Baltimore, MD, USA.
(7)Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD, USA.
(8)Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA.
(9)Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.

Abstract

A low-shrinkage-stress (LSS), antibacterial and remineralizing nanocomposite was recently developed; however, validation of its long-term antibacterial potency in modulating human salivary-derived biofilm is an unmet need. This study aimed to evaluate the antibacterial effect of the bioactive LSS composite before and after aging in acidic solution for 90 days using a multi-species biofilm model, and to evaluate its cytotoxicity. The LSS composite consisted of urethane dimethacrylate (UDMA) and triethylene glycol divinylbenzyl ether (TEG-DVBE), 3% dimethylaminohexadecyl methacrylate (DMAHDM) and 20% nanoparticles of amorphous calcium phosphate (NACP). Biofilm colony-forming units (CFU), lactic acid production, and confocal laser scanning microscopy (3D biofilm) were evaluated before and after three months of aging. Cytotoxicity was assessed against human gingival fibroblasts (HGF). The new LSS composite presented the lowest biofilm CFU, lactic acid and biofilm biomass, compared to controls (n = 6, p < 0.05). Importantly, the new composite exhibited no significant difference in antibacterial performance before and after 90-day-aging, demonstrating long-term antibacterial activity (p > 0.1). The LSS antibacterial and remineralizing composite presented a low cell viability at original extract that has increased with further dilutions. In conclusion, this study spotlighted that the new bioactive composite not only had a low shrinkage stress, but also down-regulated the growth of oral biofilms, reduced acid production, maintained antibacterial activity after the 90-day-aging, and did not compromise the cytocompatibility.