A study was conducted recently where participants were asked a series of questions of varying difficulty, from easy (i.e. What is the capitol of Minnesota) to difficult (i.e. What is the airspeed velocity of an unladen swallow). Then they were asked to gauge the confidence in their answers, from ‘100% confident’ to ‘total guess.’ Of the answers they rated as 100% confident, they were still wrong 15% of the time. While confidence is a good thing, overconfidence, or denying the possibility of error, is not. We’re all human, we’re going to be wrong from time to time whether we want to admit it or not.
This example seems particularly applicable to the great amalgam debate. On one side you have the medical research community that expresses confidence in their conclusions but is always open to more information, and on the other side you have the ‘amalgam haters’ that exude overconfidence and refuse to entertain any contrary opinions. In my experience, alarmists, conspiracy theorists and doomsayers only see things in black and white, while realists see the world in shades of gray. In other words, those who only deal in absolutes tend to rely on hype and fear to propagate their views.
The amalgam debate has mostly focused on its potential health effects. For most people, in most situations, the evidence is pretty clear that amalgam fillings are not going to cause any health problems. But health concerns are only part of the picture when it comes to the use of amalgam. Another prevalent concern is environmental. In 2009 Sweden banned amalgam altogether, along with other mercury-containing products, in a sweeping move to eliminate potential leaks into their ecosystem. Will other countries follow? Only time will tell, but the general trend is already moving in that direction, particularly in the rest of the EU.
Another concern is the long-term effectiveness of its use as a filling material. The mouth is a rather hostile environment; constantly alternating between hot and cold, acidic and basic. Restorations need to be done, and often eventually redone. The battle for oral health is never won, only ongoing.
When an amalgam filling is placed there is a microscopic gap between the filling and the tooth. Over the next month that gap is filled with “corrosion products” from the filing itself, much like rust forming on iron. This gap is then sealed and for the next few years the amalgam is fine. The problem is this corrosion process doesn’t stop, and that’s why your amalgam fillings, which started out shiny and smooth, are now black and pitted. As time goes on new openings will develop which allow fluid (saliva) to invade. This can eventually lead to stains, cracks in the enamel, and then decay. At this point the filling has effectively failed and is actually doing more harm than good.
Thankfully technology has come to the rescue. Newer bonded materials not only look better but last longer and contain no hazardous ingredients. So why haven’t they supplanted amalgam entirely? Simply: cost. Amalgam is cheap, newer materials are more expensive. While you want what’s best for your mouth, your insurance carrier usually wants what’s best for the bottom line. Like it or not, in our current healthcare system, insurance companies are still driving the bus.
There are many factors in the great amalgam debate, and while advocates on both sides continue with their philosophical arguments, ultimately the driving force behind amalgam’s survival or demise may very well be money. Perhaps we’d be overconfident to think otherwise.
Are my metal fillings safe? Part 1	Is sugar the new tobacco?