By Charles Wilson, DDS

(updated 12/2001)

I first want to say that neither I nor the dental profession as a whole have any reason (that I know of) to defend the use of amalgam. We have many other materials that we are happy to use instead of amalgam. However, I must tell you (the consumer) that the most durable and least expensive filling material is dental amalgam. White fillings cost at least 30% to 100% more and are still not as long lasting as amalgam. Other non-amalgam replacement restorations cost from 3 to 7 times (!) as much as amalgam.

If you do not want amalgam restorations in your mouth, I am very pleased to use other materials. That is why I am careful to ask my patients if they do not desire amalgam restorations (regardless of their reason) before I diagnose their treatment.  Many of you want tooth colored fillings in your mouth for cosmetic reasons alone and that is certainly a very good reason!

Then why am I writing this article about the safety of amalgam? Many of you have expressed concern about amalgam and asked my opinion about it. I believe my patients and friends deserve to know the truth about amalgam so they can make their decisions based on facts and not distortion.

Question #1: Isn’t mercury a very poisonous material that can cause serious problems in very small amounts?

Answer: Yes. Mercury is very dangerous in its elemental liquid metal form. It only takes small quantities ingested into the body through the mouth, skin, or lungs to cause mercury poisoning.  Mercury poisoning damages the brain and nerves and the damage can be permanent!

Question #2: How then can amalgam be safe if it has mercury in it?

Answer: Let me ask you a question. Do you think table salt is safe? Did you know that table salt is half chlorine? Chlorine in its elemental gas form is extremely dangerous. Small quantities of chlorine gas will kill within a few minutes. Obviously, the fact that a dangerous substance is used to make table salt does not make table salt dangerous. On the contrary, salt is necessary for life. Without salt we would die! Therefore, the fact that mercury is used to make amalgam does not necessarily make amalgam unhealthy.

Question #3: How is mercury used to make amalgam?

Answer: A small quantity of mercury is mixed with a metal powder in a small capsule before the filling is placed. A machine does this by vibrating the capsule at high speed. This is the familiar buzzing sound that you hear as the dental assistant prepares the amalgam for the dentist. The mercury chemically combines with the metal powder to form a metal alloy. For a few minutes the metal alloy has a putty like consistency that makes it possible to place it in the cavity in your tooth and to shape it. In a very short time, the chemical reaction is completed and the alloy becomes rock hard so that you can chew on it. You are never exposed to elemental liquid mercury.

Question #4: Is mercury vapor released from amalgam?

Answer: Yes it is - but in quantities so small that only very sophisticated instruments can detect it. The quantities of mercury are on the same level as those in fish and many other foods that we all consider to be safe.

Question #5: Is it possible that these very small quantities of mercury vapor could cause harm?

Answer: Yes, it is possible. That is why there has been much study of amalgam over the 150 years that it has been used as a restorative material. Every reliable study that has ever been done has shown that amalgam is not harmful. That is why the American Dental Association (and every other major medical and public health agency in the USA) has officially stated that amalgam is safe.  I know of no reliable, scientific study that show any harmful effects to the general population. 

Question #6: Is it wrong for me to have my silver fillings replaced because I am worried about the possibility that they could be hurting me?

Answer: NO, it is not wrong if you have all the undistorted facts and still feel that way. There have been a few cases of people who are allergic to amalgam. Also, there is always the remote chance that we just haven’t been able to discover a way that amalgam hurts you. If a person is concerned at all, there are good alternative materials that can be used to put your mind at rest.

Question #6: Why is there controversy about the safety of amalgam?

Answer:  I will give you my opinion. There are many factors in our culture that make us ripe for just such a controversy. We as a culture are very sensitive to environmental pollution, health issues, organic food, physical fitness, etc. White fillings (composite fillings) have recently been improved to the point that they are almost as good as silver fillings (except in the area of cost). Individuals are making money on books and TV shows that expose controversies about health related issues. We as a society are questioning traditional authorities that we have trusted in the past. The dental profession would greatly benefit if the public decided to replace the millions of silver fillings that are walking around right now. In my opinion, all of these factors together are what is driving the amalgam controversy.

Question #7: Are there any "unbiased" authorities that say amalgam is safe?

Answer: Yes. Consumer Reports and 60 Minutes did independent studies on amalgam to see what was at the bottom of the amalgam controversy. Their conclusion was that amalgam is safe and is definitely the most cost-effective restorative material. Consumer Reports said that if your dentist wants to replace your silver fillings to improve your health – hold onto your wallet and get out of there as quickly as possible!

Question #8: Are there scientific studies that show a connection between amalgam and health problems?

Answer: Yes there are but are they reliable?  There was also a scientific study a few years ago that demonstrated that cold nuclear fusion was possible. In the case of cold fusion, numerous laboratories reviewed this study and tried to duplicate it. The conclusion today is that this cold fusion study was wrong and that the scientists made some mistakes that led to the wrong results. The same is true for the handful of studies that show that amalgam is harmful. Other scientists have reviewed these studies. They have attempted to duplicate or support the results. Basic errors in the studies have been discovered that produced wrong results. Unfortunately, those individuals who quote these studies to support their contention that amalgam is harmful do not point out the errors that were made.

Question #9: What Public Institutions support the safety of amalgam?

Answer: The American Dental Assn., The U.S. Public Health Service, The Food and Drug Admin., The National Institutes of Health Technology Assessment Conference, The National Institutes of Dental Research, and many more.