title: The influence of a hyperbaric environment and increased oxygen partial pressure on the corrosion of dental alloys.
abstract: OBJECTIVE
  The purpose of this in-vitro study was to determine whether there is a correlation between a hyperbaric environment or increased oxygen partial pressure and the corrosion of dental alloys used for dental restorations in divers.
  
  
  METHODS
  Samples of three commercially available dental alloys (palladium-based, reduced-gold-content and high-gold-content) were tested in the DIN EN ISO 1562 static immersion test and the amount of dissolved ions measured by atomic absorption spectrometry. The specimens were exposed to one of the following three conditions: normobaric and normoxic conditions (PO2 21 kPa); 608 kPa (6 bar, PO2 127 kPa) pressurised air in a pressure chamber or 506 kPa (5 bar, PO2 304 kPa) pressurised nitrox in a pressure chamber.
  
  
  RESULTS
  None of the exposures suggested a correlation between increased ion solubility as a measure of corrosion and increased ambient pressure of the three alloys. The reduced-gold-content alloy released zinc ions at twice the weekly recommended dose. When the palladium-based alloy was exposed to a hyperbaric or hyperbaric/hyperoxic environment, ion solubility increased only slightly for gallium and silver.
  
  
  CONCLUSIONS
  Within the limited sample size of the current study it can be concluded that hyperbaric and/or hyperoxic conditions do not seem to be a risk for increased corrosion for any of the three tested alloys.
authors.affiliation: Department of Prosthodontics, Propaedeutics and Dental Materials, Dental School, Christian-Albrechts University, Kiel, Germany. cmehl@proth.uni-kiel.de
authors.forename: Christian
authors.initials: C
authors.lastname: Mehl
authors.forename: Frank
authors.initials: F
authors.lastname: Heblich
authors.forename: Rudolf
authors.initials: R
authors.lastname: Lenz
authors.forename: Klaus
authors.initials: K
authors.lastname: Ludwig
authors.forename: Matthias
authors.initials: M
authors.lastname: Kern
mesh_terms: D003343:Corrosion; D003722:Dental Alloys / Q000737:chemistry*; D006047:Gold Alloys / Q000737:chemistry*; D006801:Humans; D006931:Hyperbaric Oxygenation / Q000009:adverse effects*; D008422:Materials Testing; D010100:Oxygen / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D010313:Partial Pressure
chemical_list: D003722:Dental Alloys; D006047:Gold Alloys; D010165:Palladium; D010100:Oxygen