title: Oral factors affecting titanium elution and corrosion: an in vitro study using simulated body fluid.
abstract: OBJECTIVE
  Ti, which is biocompatible and resistant to corrosion, is widely used for dental implants, particularly in patients allergic to other materials. However, numerous studies have reported on Ti allergy and the in vitro corrosion of Ti. This study investigated the conditions that promote the elution of Ti ions from Ti implants.
  
  
  METHODS
  Specimens of commercially pure Ti, pure nickel, a magnetic alloy, and a gold alloy were tested. Each specimen was immersed in a simulated body fluid (SBF) whose pH value was controlled (2.0, 3.0, 5.0, 7.4, and 9.0) using either hydrochloric or lactic acid. The parameters investigated were the following: duration of immersion, pH of the SBF, contact with a dissimilar metal, and mechanical stimulus. The amounts of Ti ions eluted were measured using a polarized Zeeman atomic absorption spectrophotometer.
  
  
  RESULTS
  Eluted Ti ions were detected after 24 h (pH of 2.0 and 3.0) and after 48 h (pH of 9.0). However, even after 4 weeks, eluted Ti ions were not detected in SBF solutions with pH values of 5.0 and 7.4. Ti elution was affected by immersion time, pH, acid type, mechanical stimulus, and contact with a dissimilar metal. Elution of Ti ions in a Candida albicans culture medium was observed after 72 h.
  
  
  CONCLUSIONS
  Elution of Ti ions in the SBF was influenced by its pH and by crevice corrosion. The results of this study elucidate the conditions that lead to the elution of Ti ions in humans, which results in implant corrosion and Ti allergy.
authors.affiliation: Department of Oral and Maxillofacial Prosthodontics and Oral Implantology, Institute of Health Biosciences, The University of Tokushima, Tokushima, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Suito
authors.forename: Yuki
authors.initials: Y
authors.lastname: Iwawaki
authors.forename: Takaharu
authors.initials: T
authors.lastname: Goto
authors.forename: Yoritoki
authors.initials: Y
authors.lastname: Tomotake
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ichikawa
mesh_terms: D001826:Body Fluids / Q000187:drug effects / Q000378:metabolism*; D002176:Candida albicans / Q000187:drug effects / Q000254:growth & development; D003343:Corrosion; D003722:Dental Alloys / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007477:Ions; D012996:Solutions; D013314:Stress, Mechanical; D014025:Titanium / Q000494:pharmacology*
chemical_list: D003722:Dental Alloys; D007477:Ions; D012996:Solutions; D014025:Titanium