Back in the 1800s, dental amalgam was introduced into the dental industry and used to fabricate metal fillings. Made from an amalgamation of silver, tin, copper, and mercury, amalgam fillings were widely used for several decades because they were easy to place, affordable, and durable. Nowadays, however, many dentists have switched to placing composite fillings.
Dental composite resin was developed in the 1960s and since that time it has grown increasingly popular for procedures like fillings and composite bonding. Some dentists even fabricate veneers out of composite resin. Like dental amalgam, composite resin offers patients many benefits. Since metal fillings are now seen as outdated and composite fillings offer more benefits, many dentists are recommending that metal fillings be replaced. Here are some reasons why you should replace metal fillings with composite fillings:
Metal Fillings are Ugly
One of the most basic reasons why you should consider having metal fillings replaced with composite fillings is just because metal fillings are ugly. An amalgam filling usually takes on a dark, metallic grey appearance. Considering the fact that the rest of your teeth are likely some shade of ivory, the metallic grey will stick out like a sore thumb. Composite fillings, on the other hand, can be fabricated to match the exact shade of your natural teeth.
Metal Stains
Not only do they add a metallic gleam to your smile, but metal fillings can stain your teeth and gums as they age. This is because when their protective coating wears down from chewing, the underlying metal will start to corrode. This can cause your teeth to take on a blue, grey, or black tint. When a filling is close to the gums, it can also cause something known as an amalgam tattoo.
Loss of Natural Tooth Structure
Not only do metal fillings have the potential to stain your teeth and gums, but they can also wear down your teeth over time. For starters to place a metal filling, some of your healthy tooth structure will need to be removed in addition to the decayed tissue. Later when this filling wears out and needs to be replaced, more healthy tooth structure will likely need to be removed. Over time, this slowly wears down the natural tooth structure. Conversely, the dental composite used in composite fillings can bond directly to the enamel, meaning that little to no natural tooth structure is removed.
Can Cause Damage
Another thing to keep in mind about metal fillings is that certain metals can change shape in certain temperatures. In the case of amalgam fillings, mercury is one metal that is reactive to changes in temperature. Unfortunately, this means that eating or drinking something hot can make the filling expand, while eating or drinking something cold can cause the filling to shrink. An expanding filling will place additional stress on the surrounding tooth structure, while a shrinking filling will create a small crack between your tooth and the filling. Both types of structural changes can cause your teeth to become damaged, increase the risk of failure, and lead to tooth sensitivity.
Contains Mercury
Mercury is used as a binding agent in amalgam fillings. Around half the filling is made up of a liquid mercury mix that is added to a powder made from silver, tin, and copper. The FDA notes that the use of mercury in amalgam fillings is considered to be safe, however it is bioaccumulative. This means that it collects in your body overtime. For this reason, pregnant women, people with kidney problems, or people with pre-existing neurological conditions are recommended to avoid metal fillings.