Influence of ozone on oxidation of dental alloys.
OBJECTIVE
The purpose of this study was to examine the influence of ozone on the surface of removable partial denture (RPD) alloys to determine its usefulness as a cleaning method for RPDs, since ozone has powerful sterilizing and deodorizing properties.


METHODS
Two types of ozone cleaning were used. The quantities of ozone generated by both methods were the same (20 mg/h). In method A, ozone was generated for 10 minutes every 12 hours and in method B, ozone was generated over 24 hours a day. Test specimens of 3 types of dental alloy (Co-Cr, Au-Ag-Pt, and Au-Cu-Ag-Pd) were subjected to different cleaning methods for 7 days and measured in terms of reflectance, surface roughness, and weight. Five different cleaning solutions (three commercial denture cleaners, acid-electrolyzed water with a pH of 2.4, and pure water) were used for comparison with the ozone treatments.


RESULTS
No significant changes were detected after treatment of the Co-Cr and Au-Ag-Pt alloys with ozone. Ozone caused a slight change in the Au-Cu-Ag-Pd alloy in terms of reflectance, but the changes were significantly less than those caused by acid-electrolyzed water and one of the commercial denture cleaners.


CONCLUSIONS
Ozone had little influence on the oxidation of dental alloys.
Suzuki
T
T
Department of Geriatric Dentistry, Tokyo Medical and Dental University Faculty of Dentistry, Japan. t.suzuki.gero@dent.tmd.ac.jp
Oizumi
M
M
Furuya
J
J
Okamoto
Y
Y
Rosenstiel
S F
SF
D002858:Chromium Alloys / Q000737:chemistry; D003343:Corrosion; D003722:Dental Alloys / Q000737:chemistry*; D003820:Denture Cleansers / Q000737:chemistry*; D003832:Denture, Partial, Removable; D006047:Gold Alloys / Q000737:chemistry; D008422:Materials Testing; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry; D010984:Platinum / Q000737:chemistry; D013242:Sterilization / Q000379:methods; D013499:Surface Properties; D014867:Water / Q000737:chemistry
D002858:Chromium Alloys; D003722:Dental Alloys; D003820:Denture Cleansers; D006047:Gold Alloys; D014867:Water; D010984:Platinum; D010165:Palladium; D010126:Ozone