When I entered dentistry in 1998 I thought that the demise of silver fillings was surely at hand. They were ugly, contained mercury, and were sometimes difficult to place well. Some of these points still remain true today, but I have a new-found respect for this old material. Yes, it is ugly and contains mercury, but it can be a long lasting restorative material that is not as finicky as most of the tooth colored materials today. My rant? Amalgam material is being phased out of dentistry through fear and force, both political and social.
I will start with some background information on mercury containing fillings. Mercury is a metal found in nature as a liquid which, when heated, enters a vapor state. This happens in dentistry through the use of friction from our hand-pieces. Most mercury that is found as a contaminant was released as a vapor from industrial and commercial release. This is when problems occur because the vapor is very toxic and readily absorbed. This becomes a huge problem when silver fillings, which can be up to 50% mercury, are removed. The dentist must protect the patient, himself, and his staff from this volatile vapor. One of the ways that we help protect everyone is through the use of a dental dam which fits snugly over the tooth and keeps the patient from swallowing or inhaling any freed up particles.
Biased articles against amalgam fillings will scare you, claiming that simply chewing gum and brushing teeth can release vapors and increase the risk of mercury poisoning. There are even horrifying pictures and videos on the internet showing mercury vapor smoking out of teeth. In truth, the temperature at which mercury vaporizes is about 673 degrees Fahrenheit, which is three times the boiling point of water. I have yet to meet a food or liquid that I could consume that is that hot!
In the mid '90s, some dentists discovered the "fear factor" and tried to deter patients from amalgam fillings by calling them "silver mercury fillings." They were even able to convince their patients that "those silver mercury fillings are bad for you and should be removed. We only use tooth colored materials which are not a health risk." This was an outrageous statement, but I actually witnessed it firsthand in several offices. It was an easy way to convince a patient to have their amalgam fillings replaced when they were probably fine. This was also a dark time in dentistry when dentists discovered that a recently introduced material, pressable ceramics, could be "bonded" into teeth. Even worse was the use of chair side millable ceramics such as CEREC, which was introduced in the mid-1980s. This material was very interesting because the dentist would prepare the tooth similarly to a filling, then take an impression and have a lab, or CEREC unit, fabricate a tooth colored filling which could then be "bonded" into the tooth. I call it a dark time because thousands upon thousands of these restorations were placed and many of them failed in a very short time because the bonding technology was not there to keep the filling material from leaking and allowing new decay to form. Believe it or not, there are dentists still using this technique today.
Amalgam is...okay? Yes, according to the government and... no, according to the government. California tried to encourage the reduction of amalgam by mandating that any office that uses it must have approved devices and means for dealing with amalgam waste, including water that may be contaminated with amalgam particles. This is a very expensive proposition and caused many offices to go amalgam free just to avoid government regulation. Additionally, the transportation of mercury and mercury containing compounds is now regulated all over the US under the Hazardous Materials Transporation Act. On the flip side, the government has made many statements touting the safety and efficacy of amalgam fillings, with little or no risk to the public. In fact, there are laws that prohibit a dentist from recommending the removal and replacement of amalgam fillings, just for the sake of reducing a health risk.
How about my office? We are essentially amalgam free, and only out of convenience. Amalgam contains silver, mercury, tin, and other materials. It contaminates all the instruments it touches with a "silver" residue. If those instruments are accidentally used with other materials, it can impart a grey hue, which is unsightly and unexpected. We have invested thousands of dollars and hundreds of continuing education hours to make all tooth colored restorations in our office as attractive and successful as possible. We strive to stay on top of technological advances in materials and equipment to make every restoration as good as it can be. We have never recommended the removal of amalgam fillings just for the sake of doing so. If an amalgam is failing we will replace it with a tooth colored material.
Of course I've checked my facts on all this, but as always this blog is strictly an expression of my opinions based on years of dental experience. As such, none of this should be taken as a direct fact- unless you see my logic and agree with me.