title: Orthodontic cement with protein-repellent and antibacterial properties and the release of calcium and phosphate ions.
abstract: White spot lesions often occur in orthodontic treatments. The objective of this study was to develop a novel resin-modified glass ionomer cement (RMGI) as an orthodontic cement with protein-repellent, antibacterial and remineralization capabilities.
  
  
  
  Protein-repellent 2-methacryloyloxyethyl phosphorylcholine (MPC), antibacterial dimethylaminohexadecyl methacrylate (DMAHDM), nanoparticles of silver (NAg), and nanoparticles of amorphous calcium phosphate (NACP) were incorporated into a RMGI. Enamel shear bond strength (SBS) was determined. Calcium (Ca) and phosphate (P) ion releases were measured. Protein adsorption onto specimens was determined by a micro bicinchoninic acid method. A dental plaque microcosm biofilm model was tested.
  
  
  
  Increasing the NACP filler level increased the Ca and P ion release. Decreasing the solution pH increased the ion release. Incorporating MPC into RMGI reduced protein adsorption, which was an order of magnitude less than that of commercial controls. Adding DMAHDM and NAg into RMGI yielded a strong antibacterial function, greatly reducing biofilm viability and acid production. Biofilm CFU counts on the multifunctional orthodontic cement were 3 orders of magnitude less than that of commercial control (p<0.05). These benefits were achieved without compromising the enamel shear bond strength (p>0.1).
  
  
  
  A novel multifunctional orthodontic cement was developed with strong antibacterial and protein-repellent capabilities for preventing enamel demineralization.
  
  
  
  The new cement is promising to prevent white spot lesions in orthodontic treatments. The method of incorporating four bioactive agents may have wide applicability to the development of other bioactive dental materials to inhibit caries.
authors.affiliation: Department of Orthodontics, School of Stomatology, Capital Medical University, Beijing, China; Biomaterials & Tissue Engineering Division, Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland Dental School, Baltimore, MD 21201, USA.
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
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: Biomaterials & Tissue Engineering Division, Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland Dental School, Baltimore, MD 21201, USA; State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
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: 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: D000900:Anti-Bacterial Agents; D002118:Calcium; D003738:Dental Cements; D007477:Ions; D008689:Methacrylates; D010767:Phosphorylcholine / Q000031:analogs & derivatives
chemical_list: D000900:Anti-Bacterial Agents; D003738:Dental Cements; D007477:Ions; D008689:Methacrylates; D010767:Phosphorylcholine; C070638:2-methacryloyloxyethyl phosphorylcholine; D002118:Calcium
keywords: Antibacterial property; Calcium phosphate nanoparticles; Enamel bond strength; Orthodontic cement; Protein repellent; White spot lesions