title: Macromolecular leakage beneath full cast crowns: A two-year in vitro investigation.
abstract: BACKGROUND
  Most microleakage studies have used low molecular weight dyes or isotopes rather than clinically relevant materials such as lipopolysaccharides (LPSs) or cell wall materials that have been shown to provoke inflammatory reactions in the dental pulp.
  
  
  OBJECTIVE
  This investigation evaluated the leakage (diffusion) of fluorescently labeled LPS and dextran beneath cast-gold crowns luted with 3 cements.
  
  
  METHODS
  Thirty extracted molars were prepared for crowns. Ten crowns with access ports (facial or lingual) were cast in gold and luted with zinc phosphate, glass ionomer, and an adhesive resin cement onto their preparations. Teeth and crowns with filters inserted into the ports were immersed in a solution of labeled macromolecules (TRITC-LPS, FITC-dextran) and evaluated for leakage every month for 24 months. Filters were retrieved and analyzed with fluorescent microscopy.
  
  
  RESULTS
  All filters retrieved from crowns luted with zinc phosphate, glass ionomer, and adhesive resin cements demonstrated no detectable leakage and were negative for both FITC-dextran and TRITC-LPS for all evaluation periods.
  
  
  CONCLUSIONS
  For the 24 months of this investigation, zinc phosphate, Ketac-Cem, and C&B-Metabond were equally effective at preventing leakage of detectable molecular concentrations of LPS and dextran to the level of the access ports.
authors.affiliation: College of Dentistry, New York University, New York, NY, USA. ajc1@is3.nyu.edu
authors.forename: A J
authors.initials: AJ
authors.lastname: Coleman
authors.forename: M S
authors.initials: MS
authors.lastname: Moses
authors.forename: H H
authors.initials: HH
authors.lastname: Rickerby
mesh_terms: D001896:Boron Compounds; D003442:Crowns; D003763:Dental Leakage / Q000175:diagnosis* / Q000517:prevention & control*; D003764:Dental Materials; D017220:Dentin-Bonding Agents; D003911:Dextrans; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D005899:Glass Ionomer Cements; D006047:Gold Alloys; D006801:Humans; D008070:Lipopolysaccharides; D008277:Magnesium Oxide; D008689:Methacrylates; D008768:Methylmethacrylates; D008963:Molar; D011076:Polycarboxylate Cement; D019279:Resin Cements; D012116:Resins, Plant; D012235:Rhodamines; D015034:Zinc Oxide; D015036:Zinc Phosphate Cement
chemical_list: D001896:Boron Compounds; D003764:Dental Materials; D017220:Dentin-Bonding Agents; D003911:Dextrans; D005456:Fluorescent Dyes; D005899:Glass Ionomer Cements; D006047:Gold Alloys; D008070:Lipopolysaccharides; D008689:Methacrylates; D008768:Methylmethacrylates; D011076:Polycarboxylate Cement; D019279:Resin Cements; D012116:Resins, Plant; D012235:Rhodamines; C023806:Copalite; D008277:Magnesium Oxide; C009434:tetramethylrhodamine isothiocyanate; D015036:Zinc Phosphate Cement; C040235:Ketac-cem; C049495:Super-bond; D016650:Fluorescein-5-isothiocyanate; D015034:Zinc Oxide