http://www.gold.org/discover/sci_indu/GBull/2003_3/GB%203%20Knosp.pdf
The historical development work concerning the use of gold in
conservative and restorative dentistry has provided the
industry with a wide array of gold-based dental alloys suitable
for application in an extensive range of uses.If longevity,
functionality,aesthetics,and biocompatibility,together with
ease of manufacture are considered as the most important
requirements,the optimum material for dental restorations is
still a well-approved high gold alloy.It is no co-incidence that in
all testing and development of competing materials,gold is
always defined as the standard material to be judged against.
It is interesting to note that if practising dentists are asked what
type of material for a restoration they prefer for themselves,
with few exceptions the answer is always gold (13).
For several years,research teams have been attempting to
find a correlation between the corrosion behaviour and the
cytotoxic effects of dental alloys.However,it is reasonable to
state that the relationships between corrosion,the released
corrosion products and the cytotoxic response have not yet
been clearly established.Different ions are released at
different rates from the alloy:gold,indium and palladium do
not dissolve in commonly used cell culture media,whereas
silver,copper,gallium,nickel and zinc are dissolved after a
defined period under identical experimental conditions.
However,gold and platinum show no dissolution in artificial
saliva,but other ions especially indium,copper,zinc,gallium,
cobalt,and nickel,are detected.The dissolution behaviour of
alloys can be different under other experimental conditions
and it is generally recognized that the nature,rather than the
quantity of released corrosion products,is important for
(a)(b)