|Budget Amount *help
¥2,000,000 (Direct Cost : ¥2,000,000)
Fiscal Year 1997 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1996 : ¥1,300,000 (Direct Cost : ¥1,300,000)
The purpose of this study was to evaluate a new measuring method of released metallic ions, in order to clarify the mechanism of allergy. As compared with the conventional method by EPMA analysis of metal restorations, the advantages of this method are simplicity of handling and time saving. Firstly, it was determined the conditions nesessary for measurements of the released metallicions within the oral cavity. The basic experiment examined 3 types of measuring device, such as spectrophotometer, electrophotometer and visual colorimetric way. As a result, spectrophotometric measurement was selected. Secondly, the clinical experiments involed 6 subjects wearing occlusal mental splint on the maxillary dentition and the experimental splints were prepared Ni-Cr alloy and Co-Cr alloy which were considered to be dental materials having a high allergy rate. After lateral jaw movement during 5 minutes, it was attempted to judge on released metallic ions with the spectrophotometer and reagent set for water analyzer.
THe results were as follows : 1) The average volumes of Cr-ion released from Ni-Cr alloy were 0.139mg/1 (maximum : 0.293mg/1, minimum : 0.06mg/1). 2) The average volumes of Ni-ion released from Ni-Cr alloy were 0.654mg/1 (maximum : 1.094mg/1, minimum : 0.496mg/1). 3) The average volumes of Cr-ion released from Co-Cr alloy were 0.08mg/1 (maximum : 0.141mg/1, minimum : 0.022mg/1).
In conclusion, it can be said that the simplified measurements of released metallic ions were capable for clinical judgment on condition that were applied full mouth restrations.