title: Novel dental adhesive with triple benefits of calcium phosphate recharge, protein-repellent and antibacterial functions.
abstract: A new adhesive containing nanoparticles of amorphous calcium phosphate (NACP) with calcium (Ca) and phosphate (P) ion rechargeability was recently developed; however, it was not antibacterial. The objectives of this study were to: (1) develop a novel adhesive with triple benefits of Ca and P ion recharge, protein-repellent and antibacterial functions via dimethylaminohexadecyl methacrylate (DMAHDM) and 2-methacryloyloxyethyl phosphorylcholine (MPC); and (2) investigate dentin bond strength, protein adsorption, Ca and P ion concentration, microcosm biofilm response and pH properties.
  
  
  
  MPC, DMAHDM and NACP were mixed into a resin consisting of ethoxylated bisphenol A dimethacrylate (EBPADMA), pyromellitic glycerol dimethacrylate (PMGDM), 2-hydroxyethyl methacrylate (HEMA) and bisphenol A glycidyl dimethacrylate (BisGMA). Protein adsorption was measured using a micro bicinchoninic acid method. A human saliva microcosm biofilm model was tested on resins. Colony-forming units (CFU), live/dead assay, metabolic activity, Ca and P ion concentration and biofilm culture medium pH were determined.
  
  
  
  The adhesive with 5% MPC+5% DMAHDM+30% NACP inhibited biofilm growth, reducing biofilm CFU by 4 log, compared to control (p<0.05). Dentin shear bond strengths were similar (p>0.1). Biofilm medium became a Ca and P ion reservoir having ion concentration increasing with NACP filler level. The adhesive with 5% MPC+5% DMAHDM+30% NACP maintained a safe pH>6, while commercial adhesive had a cariogenic pH of 4.
  
  
  
  The new adhesive with triple benefits of Ca and P ion recharge, protein-repellent and antibacterial functions substantially reduced biofilm growth, reducing biofilm CFU by 4 orders of magnitude, and yielding a much higher pH than commercial adhesive. This novel adhesive is promising to protect tooth structures from biofilm acids. The method of using NACP, MPC and DMAHDM is promising for application to other dental materials to combat caries.
authors.affiliation: Department of Orthodontics, School of Stomatology, Capital Medical University, Beijing, China; Department of Endodontics, Periodontics and Prosthodontics, University of Maryland Dental School, Baltimore, MD 21201, USA.
authors.forename: Xianju
authors.initials: X
authors.lastname: Xie
authors.affiliation: Department of Endodontics, Periodontics and Prosthodontics, University of Maryland Dental School, Baltimore, MD 21201, USA; VIP Integrated Department, Stomatological Hospital of Jilin University, Changchun, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Endodontics, Periodontics and Prosthodontics, University of Maryland Dental School, Baltimore, MD 21201, USA; Department of Dentistry, China Rehabilitation Research Center, Beijing, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Xing
authors.affiliation: Department of Orthodontics, School of Stomatology, Capital Medical University, Beijing, China; Department of Endodontics, Periodontics and Prosthodontics, University of Maryland Dental School, Baltimore, MD 21201, USA.
authors.forename: Ke
authors.initials: K
authors.lastname: Zhang
authors.affiliation: Department of Endodontics, Periodontics and Prosthodontics, University of Maryland Dental School, Baltimore, MD 21201, USA.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Weir
authors.affiliation: L.D. Caulk Division, Dentsply Sirona Restorative, Milford, DE 19963, USA.
authors.forename: Huaibing
authors.initials: H
authors.lastname: Liu
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: Department of Endodontics, Periodontics and Prosthodontics, 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; Department of Mechanical Engineering, University of Maryland, Baltimore County, MD 21250, USA. Electronic address: hxu@umaryland.edu.
authors.forename: Hockin H K
authors.initials: HHK
authors.lastname: Xu
mesh_terms: D000900:Anti-Bacterial Agents; D018441:Biofilms; D002130:Calcium Phosphates; D003738:Dental Cements; D006801:Humans; D008689:Methacrylates; D053758:Nanoparticles; D010767:Phosphorylcholine / Q000031:analogs & derivatives
chemical_list: D000900:Anti-Bacterial Agents; D002130:Calcium Phosphates; D003738:Dental Cements; D008689:Methacrylates; D010767:Phosphorylcholine; C070638:2-methacryloyloxyethyl phosphorylcholine; C005044:hydroxyethyl methacrylate
keywords: Antibacterial; Calcium phosphate nanoparticles; Caries inhibition; Dental adhesive; Human saliva microcosm biofilm; Protein repellent