Protein-repellent and antibacterial dental composite to inhibit biofilms and caries

Abstract

Objectives Biofilm acids contribute to secondary caries, which is a main reason for dental restoration failures. The objectives of this study were to: (1) develop a protein-repellent and antibacterial composite, and (2) investigate the effects of combining 2-methacryloyloxyethyl phosphorylcholine (MPC) with quaternary ammonium dimethylaminohexadecyl methacrylate (DMAHDM) on composite mechanical properties and biofilm response for the first time. Methods MPC, DMAHDM and glass particles were mixed into a dental resin composite. Mechanical properties were measured in three-point flexure. Protein adsorption onto the composites was measured by a micro bicinchoninic acid method. A human saliva microcosm model was used to grow biofilms on composites. Colony-forming unit (CFU) counts, live/dead assay, metabolic activity, and lactic acid production of biofilms were determined. Results Incorporation of 3% MPC and 1.5% DMAHDM into composite achieved protein-repellent and antibacterial capabilities without compromising the mechanical properties. Composite with 3% MPC + 1.5% DMAHDM had protein adsorption that was 1/10 that of a commercial composite (p < 0.05). The composite with 3% MPC + 1.5% DMAHDM had much greater reduction in biofilm growth than using MPC or DMAHDM alone (p < 0.05). Biofilm CFU counts on composite with 3% MPC + 1.5% DMAHDM were more than three orders of magnitude lower than that of commercial control. Conclusions Dental composite with a combination of strong protein-repellent and antibacterial capabilities was developed for the first time. Composite with MPC and DMAHDM greatly reduced biofilm activity and is promising to inhibit secondary caries. The dual agents of MPC plus DMAHDM may have wide applicability to other dental materials.

Biological evaluation of subgingivally placed direct resin composite materials

“…Recent studies have reported technological improvements in composite resin. Of particular interest are antibacterial additives that might reduce secondary caries and biofilms and enhance remineralization of teeth (29)(30)(31). Thus, material-induced reactions should be expected when margins beyond the CEJ are required.…”

Protein-repellent and antibacterial functions of a calcium phosphate rechargeable nanocomposite

“…Disks with 2-day biofilms were transferred into tubes with 2 mL of CPW, and the biofilms were harvested by sonication and vortexing [35,36]. Three types of agar plates were prepared.…”

“…glass fillers (referred to as "EBPM+NACP+MPC"); MPC mass fraction in the composite was 3% because a previous study showed that this yielded a strong protein-repellent property without compromising mechanical properties [36].…”

“…Recently, a new dimethylaminohexadecyl methacrylate (DMAHDM) was synthesized and incorporated into dental resin, which showed the strongest antibacterial effect among the antibacterial monomers tested [35]. In addition, 2-methacryloyloxyethyl phosphorylcholine (MPC) was incorporated into resins to repel protein and bacterial attachment [36]. However, to date, literature and patent searches revealed no report on rechargeable CaP dental composite that is also antibacterial.…”

“…The pH measurements were not collected from 0 h to 24 h of culture, because the planktonic bacteria in the growth medium would affect the pH values. In this way, the measured pH was only related to the biofilm adherent on the composite disk, and there was no non-adherent bacteria contribution from the medium [35,36]. The pH data were recorded once every hour from 24 h to 36 h of the incubation.…”