title: Zinc incorporation improves biological activity of beta-tricalcium silicate resin-based cement.
abstract: BACKGROUND
  Matrix metalloproteinase (MMP) inhibition may improve endodontic treatment prognosis. The purpose of this study was to determine if zinc incorporation into experimental resin cements containing bioactive fillers may modulate MMP-mediated collagen degradation of dentin.
  
  
  METHODS
  Human dentin samples untreated and demineralized using 10% phosphoric acid or 0.5 mol/L EDTA were infiltrated with the following experimental resins: (1) unfilled resin, (2) resin with Bioglass 45S5 particles (OSspray, London, UK), (3) resin with beta-tricalcium silicate particles (βTCS), (4) resin with zinc-doped Bioglass 45S5, and (5) resin with zinc-doped βTCS particles. The specimens were stored in artificial saliva (for 24 hours, 1 week, and 4 weeks) and submitted to radioimmunoassay to quantify C-terminal telopeptide. Scanning electron microscopy analysis was also undertaken on dentin samples after 4 weeks of storage.
  
  
  RESULTS
  Collagen degradation was prominent both in phosphoric acid and EDTA-treated dentin. Resin infiltration strongly reduced MMP activity in demineralized dentin. Resin containing Bioglass 45S5 particles exerted higher and stable protection of collagen. The presence of zinc in βTCS particles increases MMP inhibition. Different mineral precipitation was attained in dentin infiltrated with the resin cements containing bioactive fillers.
  
  
  CONCLUSIONS
  MMP degradation of dentin collagen is strongly reduced after resin infiltration of dentin. Zinc incorporation in βTCS particles exerted an additional protection against MMP-mediated collagen degradation. However, it did not occur in resin containing Bioglass 45S5 particles, probably because of the formation of phosphate-zinc compounds.
authors.affiliation: Department of Dental Materials, School of Dentistry, Campus de Cartuja s/n, University of Granada, Granada, Spain. Electronic address: rosorio@ugr.es.
authors.forename: Raquel
authors.initials: R
authors.lastname: Osorio
authors.affiliation: Department of Dental Materials, School of Dentistry, Campus de Cartuja s/n, University of Granada, Granada, Spain.
authors.forename: Monica
authors.initials: M
authors.lastname: Yamauti
authors.affiliation: Dental Biomaterials and Minimally Invasive Dentistry, Departamento de Odontología, Facultad de Ciencias de la Salud, Universidad CEU-Cardenal Herrera, Valencia, Spain.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Sauro
authors.affiliation: Biomaterials, Biomimetics and Biophotonics Research (B3), King's College London Dental Institute, Guy's Dental Hospital, London, UK.
authors.forename: Tim F
authors.initials: TF
authors.lastname: Watson
authors.affiliation: Department of Dental Materials, School of Dentistry, Campus de Cartuja s/n, University of Granada, Granada, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Toledano
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D001672:Biocompatible Materials / Q000737:chemistry*; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D017610:Calcium Compounds / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry; D003094:Collagen / Q000648:ultrastructure; D024042:Collagen Type I / Q000032:analysis; D003188:Composite Resins / Q000737:chemistry; D003804:Dentin / Q000201:enzymology / Q000648:ultrastructure; D004492:Edetic Acid / Q000737:chemistry; D004577:Electron Probe Microanalysis; D005898:Glass / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D061965:Matrix Metalloproteinase Inhibitors / Q000737:chemistry; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D010455:Peptides / Q000032:analysis; D010756:Phosphoric Acids / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry; D020011:Protective Agents / Q000737:chemistry*; D019279:Resin Cements / Q000737:chemistry*; D012464:Saliva, Artificial / Q000737:chemistry; D017640:Silicates / Q000737:chemistry; D013997:Time Factors; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D017610:Calcium Compounds; D002130:Calcium Phosphates; D024042:Collagen Type I; D003188:Composite Resins; D061965:Matrix Metalloproteinase Inhibitors; D008689:Methacrylates; D010455:Peptides; D010756:Phosphoric Acids; D011109:Polymethacrylic Acids; D011140:Polyurethanes; D020011:Protective Agents; D019279:Resin Cements; D012464:Saliva, Artificial; D017640:Silicates; C485817:beta-tricalcium phosphate; C425330:bioactive glass 45S5; C052929:collagen type I trimeric cross-linked peptide; C029824:urethane dimethacrylate luting resin; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; C506393:tricalcium silicate; D017438:Bisphenol A-Glycidyl Methacrylate; C005044:hydroxyethyl methacrylate; D003094:Collagen; D004492:Edetic Acid; C030242:phosphoric acid; D015034:Zinc Oxide
keywords: Bioactive fillers; Bioglass; EDTA; calcium phosphate; collagen; demineralization; dentin; metalloproteinases; phosphoric acid; remineralization; zinc