Novel multifunctional nanocomposite for root caries restorations to inhibit periodontitis-related pathogens.

The objectives of this study were to: (1) develop a novel multifunctional composite with nanoparticles of silver (NAg), 2-methacryloyloxyethyl phosphorylcholine (MPC), dimethylaminohexadecyl methacrylate (DMAHDM) and nanoparticles of amorphous calcium phosphate (NACP); and (2) investigate biofilm-inhibition via the multifunctional nanocomposite against three species of periodontal pathogens for the first time. The multifunctional nanocomposite was fabricated by incorporating NAg, MPC, DMAHDM and NACP into the resin consisting of pyromellitic glycerol dimethacrylate (PMDGDM) and ethoxylated bisphenol A dimethacrylate (EBPADMA). Three species (Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum) were tested for metabolic activity (MTT), live/dead staining, polysaccharide production and colony-forming units (CFU) of biofilms grown on resins. Incorporation of 0.08% to 0.12% NAg, 3% MPC, 3% DMAHDM and 30% NACP did not compromise the mechanical properties of the composite (p > 0.1). The multifunctional nanocomposite reduced protein adsorption to nearly 1/10 of that of a commercial control (p < 0.05). For all three species, the biofilm CFU was reduced by about 5 and 1 orders of magnitude via the nanocomposite containing NAg + MPC + DMAHDM, compared to commercial control and the composite with MPC + DMAHDM, respectively. The novel multifunctional nanocomposite achieved the greatest reduction in metabolic activity, polysaccharide and biofilm growth of three periodontal pathogens. The strongly-antibacterial, multifunctional composite is promising for treating root lesions, alleviating periodontitis and protecting the periodontal tissues.