title: [The effects of pH in artificial saliva on the corrosion resistance of magnetic retainers].
abstract: OBJECTIVE
  The aim of this article was to discover the corrosion resistance of magnetic attachments, which were encapsulated in stainless steel, when pH value of artificial saliva was lower than normal.
  
  
  METHODS
  Three kinds of magnetic retainers were exposed for 6 months to artificial saliva with pH ranging from 5.6 to 7.0, thermostated at 36.5 degrees C. This study included electrochemical test as polarization curves, chemical test as immersion test and SEM to analyze the corrosion behavior of the materials.
  
  
  RESULTS
  Fe3+ ions in stainless steel released more than ten times in an environment pH 5.6 than pH 7.0. The higher concentration of H+, the more elemental release. That pH value of artificial saliva reduced may affect the corrosion speed. The magnetic retainers were not resistant to acidic environments during exposure.
  
  
  CONCLUSIONS
  Transient exposure of stainless steel to an acidic oral environment can increase elemental release significantly. So acid resistance of magnetic retainers was relatively weak, and it would affect the life span of magnets.
mesh_terms: D003343:Corrosion; D003764:Dental Materials; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008280:Magnetics; D008422:Materials Testing; D012464:Saliva, Artificial; D013193:Stainless Steel
chemical_list: D003764:Dental Materials; D012464:Saliva, Artificial; D013193:Stainless Steel