Why Do Dentists Like Gold?
Back when gold was more affordable it was a restorative filling of choice. When I took my licensing examination I had to do a gold inlay (replacing a small part of the tooth) on a patient in order to pass.
So, what are the advantages?
Gold is very stable in the mouth. A well made inlay, onlay (like an inlay but covers at least one “cusp” of the tooth), or crown (covers the whole tooth) can last many years once cemented. I have patients who have had gold restorations done 30 years ago and they are still doing a good job.
Another positive property is it does not wear down the opposing tooth while not being worn down by it either. In other words, the frictional properties of gold are similar to that of amalgam. This is not the case with all dental materials.
Another good thing about gold is that it is malleable, which means that the gold can move a little by hammering (we won’t do that in the mouth!) or burnishing (which is rubbing the material and getting it to move). This part doesn’t come up too much, but only if there is a space between the tooth and inlay.
Gold is not used in it’s pure form because it is much too soft. For dental uses it is typically between 75% and 80% pure with other metals as part of the alloy (an alloy is a mixture of 2 or more metals melted together).
One of the great advances of the 1960s and 1970s was a way to get porcelain to bond to gold. This is not pure gold but an alloy of a lower percentage of gold. This material offered a stronger and more durable crown compared to the all porcelain materials of the day. In present time there are replacements for gold with semi-precious and non-precious alloys, or with stronger porcelains which have been recently developed.
What are the down sides to gold?
The obvious one is the looks. Some people and cultures like gold whereas for others it is an eyesore.
The escalating cost of gold has made it a very expensive option for dental work. We don’t use a whole lot of gold, but it is enough to raise the cost of the material by $50-$150 which then has to be passed on to the consumer.
Gold, like any metal, can set up a Galvanic reaction in the mouth, especially when there are other types of metal fillings in their mouth (like amalgams). I was taught that eating a hard boiled egg, which provides Sulfur, can break up the flow.
A more debatable short coming is the fact that it is a metal. Alternative medicine practitioners have told me that they do not like metal in their patients’ mouths because it can alter the normal flow of electricity in their body. The composite fillings seem not to effect this electrical flow.
I use gold only by special request, usually in patients who have had much gold work done in the past. They are informed of the cost increase and can make an informed decision.