|
KMID : 0362219930200020107
|
|
Journal of The Korean Research Society for Dental Materials
1993 Volume.20 No. 2 p.107 ~ p.124
|
|
|
Corrosion Behavior of Amalgam, Gold and Nickel-Chromium Alloys in Contact
|
|
|
|
|
Abstract
|
|
|
The purpose of this study was the effect of area ratio, the difference of electrolyte between artificial saliva and 0.9% NaCl solution and that of corrosion rate on amalgam in contact with the dental casting gold and the nickel-chromium alloy by
measuring the amount of elements released in the electrolyte usin Inductively Coupled Plasma Emission Spectroscopy (ICPES)
After each amalgam alloy and Hg was triturated as the direction of the dmanufacturer by means of the mechanical amalgamator, the triturated mass was inserted into the disk shaped stainless steel mold 5mm in diameter and 4mm thick and condensed by
using
routine manner. The excess amalgam on the surface was removed by razor blade. Twenty-four hous after condensation, samples were removed from the moldas and the standard surface preparation was routinely carried out. The specimens of casting gold
and
nickel-chromium alloy were all made from wax patterns prepared in a matrix with the same shape(30x10x1mm). Investing and casting were done according to the recommendations of each manufacturer. These specimens were groumd with silicone carbdide
papers(#600) and polished. The polished samples were ultrasonically cleaned, rinsed in acetone solution and dried.
Amalgam plugs was inserted into the casting gold and nickel-chromium alloy plates.
The dental casting gold and nickel-chromium alloys were stored at 37℃±1℃ in glass beaker for 12 weeks in contact with a high copper amalgam, area relations 6 : 3, in an electrolyte of artificial saliva and 0.9% NaCl solution. The solutions
were
renewed each 4 weeks and analyzed for Cu, Zn, Sn, Hg, and Ag in an Inductively Coupled Plasma Emission Spectroscopy (ICPES).
From the experiments, following results were obtained :
1. In the case of amalgam in contaet with dental casting gold alloy in the amount of the copper released was greatest.
2. Generally, a corrosion reaction in the dental casting gold alloy I contact with amlgam was more severe than in the nickel-chromium alloy and in the acrylic resin.
3. The amount of elements released in the 0.9% NaCl solution was much more than in the artificial saliva solution and pH values of both of solutions were increased from 5.8 to 8.5.
4. The tendency for tin(Sn) to be released from the amalgam was greatest during the first 4 weeks and decreased with time elapsed, and silver(Ag) was greatest from the beginning of 9 weeks.
5. The amount of the metal elements released per cm2 amalgam was larger for the 1:6 than for the 3:6 amalgam gold ratio.
6. In the case of dental casting nickel-chromium alloys in contact with amalgam, the amount of another metal elements released was decreased due to severe releasing of nickel.
7. The corrosion rate of the amalgam was more influenced by the type of electrolyte than than by the type of the dental casting alloy.
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
Listed journal information
|
|
|
|