title: Protein-repellent and antibacterial dental composite to inhibit biofilms and caries.
abstract: OBJECTIVE
  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 containing MPC and DMAHDM greatly reduced biofilm growth and lactic acid production, without compromising mechanical properties of the composite.
  
  
  CONCLUSIONS
  Novel 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.
authors.affiliation: Biomaterials & Tissue Engineering Division, Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland Dental School, Baltimore, MD 21201, USA; Department of Orthodontics, School of Stomatology, Capital Medical University, Beijing, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
authors.affiliation: School & Hospital of Stomatology, Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Ma
authors.affiliation: Biomaterials & Tissue Engineering Division, Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland Dental School, Baltimore, MD 21201, USA.
authors.forename: Mary A S
authors.initials: MA
authors.lastname: Melo
authors.affiliation: Biomaterials & Tissue Engineering Division, Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland Dental School, Baltimore, MD 21201, USA.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Weir
authors.affiliation: Department of Orthodontics, School of Stomatology, Capital Medical University, Beijing, China. Electronic address: byuxing@263.net.
authors.forename: Yuxing
authors.initials: Y
authors.lastname: Bai
authors.affiliation: Biomaterials & Tissue Engineering Division, Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland Dental School, Baltimore, MD 21201, USA; Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Mechanical Engineering, University of Maryland, Baltimore County, MD 21250, USA. Electronic address: hxu@umaryland.edu.
authors.forename: Hockin H K
authors.initials: HH
authors.lastname: Xu
mesh_terms: D000180:Acrylic Resins / Q000494:pharmacology* / Q000627:therapeutic use*; D000327:Adsorption; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use*; D018441:Biofilms / Q000187:drug effects*; D015169:Colony Count, Microbial; D003188:Composite Resins / Q000494:pharmacology* / Q000627:therapeutic use*; D003731:Dental Caries / Q000188:drug therapy*; D006801:Humans; D008689:Methacrylates / Q000494:pharmacology / Q000627:therapeutic use; D050296:Microbial Viability / Q000187:drug effects; D010767:Phosphorylcholine / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use; D011140:Polyurethanes / Q000494:pharmacology* / Q000627:therapeutic use*; D011506:Proteins / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D000180:Acrylic Resins; D000900:Anti-Bacterial Agents; C029012:Composite Dental Resin; D003188:Composite Resins; D008689:Methacrylates; D011140:Polyurethanes; D011506:Proteins; D000644:Quaternary Ammonium Compounds; D010767:Phosphorylcholine; C070638:2-methacryloyloxyethyl phosphorylcholine
keywords: Antibacterial property; Caries inhibition; Human saliva microcosm biofilm; Mechanical property; Protein repellent; Resin composite