When it comes to amalgam vs. composite fillings, there are both benefits and drawbacks. We discuss both to help give you a better understanding.
“You have a cavity.” It’s generally not a sentence that we enjoy hearing from our dentist. However, with the advancements made in dentistry, there are several different options to consider for tooth repair. While traditional silver amalgam fillings used to be the only choice available, today most dental offices also provide composite resin.
Both materials offer certain benefits and drawbacks. Knowing what those are in advance can help you make an educated decision on the type of dental filling you want, should the need for one arise. Although it’s possible to coast through life without ever developing a cavity, there is a pretty good chance you will need a dental filling at some point in your life. It is estimated that around 90 percent of Americans between the ages of 20 and 64 have at least one cavity, with that number increasing to 96 percent for people over the age of 65.
Before diving into the pros and cons of the materials used for dental fillings, let’s discuss what a dental filling is and how it can improve oral health and beauty. Dental fillings are designed to replace decay in tooth enamel and restore a tooth’s appearance, strength, and structure. 
Although dental enamel is the strongest tissue in your body, it is susceptible to bacteria.
Plaque is a naturally occurring matrix of minerals and bacteria that forms on teeth. As plaque builds up, bacteria accumulate. The bacteria eat starches and sugars, then create an acidic byproduct. Acid softens enamel, causing erosion, dental sensitivity, and allowing bacteria can invade and cause cavities. If left untreated, the harmful bacteria eat away enamel and underlying tissue, causing a cavity. Left untreated, the decay can penetrate a tooth’s canal, which results in the need for root canal therapy or tooth extraction.
To place a dental filling, the dentist will remove bacteria and decay, thoroughly clean the tooth, and apply a dental filling into the prepared hole to reinforce the tooth’s structural integrity. With the dental filling in place, you can enjoy restored function and better oral health.
Amalgam fillings are made from a variety of metals, such as silver, mercury, zinc, and copper. They are often referred to as silver or metal fillings. Compared to composite resin, this type of filling is more affordable and offers longer-lasting results. When properly cared for, an amalgam filling can last up to 15 years. Because of the metal alloy used, amalgam fillings offer stronger resistance to damage, making then a superior choice for larger areas of decay.
However, in recent years, amalgam fillings have a developed a bad reputation due to the mercury in the material used. Mercury is a heavy metal and some patients are particularly sensitive or allergic to it. Another downside is its appearance. Silver fillings are more noticeable, especially when laughing or open-mouth smiling. Over time, amalgam filling can darken the appearance of the entire tooth, making it appear grayish and dull, negatively impacting the overall look of a smile.
Composite fillings, also known as tooth-colored fillings, are made from a combination of acrylic and ceramic that can be tailor-matched to blend beautifully with your natural tooth enamel. Composite resin offers an aesthetically-pleasing restoration. It also requires less enamel removal and tooth preparation, allowing you to maintain as much of your natural tooth structure as possible.
The cons to composite fillings are cost and longevity. As a newer treatment in the dental industry, composite fillings are not as cost-effective as amalgam fillings. Composite resin fillings have a longer treatment time, which adds to the cost. Since composite is not as durable as metal alloy, results generally last about seven to 10 years.
A tooth close to the front of your mouth that is easily seen when smiling or laughing will look more natural with a composite filling. For teeth in the back of the mouth that have greater decay, an amalgam filling is the better choice, due to its durability and longevity. If you are concerned about aesthetics or the mercury content in filling, ask your dentist if a dental crown, inlay, or onlay may be a good alternative.