Which Filling Material Should You Get?
Many people prefer to have white fillings because they are less noticeable. At my dental school we usually recommend amalgam fillings for the back teeth and composite resin fillings for the front teeth. In order to assist you in making an informed decision, here is a short list of eight factors to consider:
1 – Amalgam fillings are stronger than composite fillings. We recommend amalgam fillings on the back teeth because that is where the majority of the forces are when you bite down. Since amalgam is made of various metals, it is a very strong material. Composite resin fillings wear down faster than amalgam fillings and need to be replaced more often.
2 – Amalgam fillings last longer than composite fillings. I’m sure that with future technological advancements, composite fillings will probably last as long as amalgam fillings someday. But for right now, if you want your filling to last a long time, you should choose amalgam. To learn more about the duration of each type of filling you can read this post on my blog: Which Type of Filling Lasts Longer, White or Silver?
3 – Composite fillings are less noticeable than silver amalgam fillings. If you get an amalgam filling on a back tooth, most likely only you and your dentist will notice it. But if you don’t like seeing silver in your mouth at all, then a composite filling is probably the way to go.
4 – Amalgam fillings contain mercury. As I mentioned above, the mercury in the amalgam fillings gets incorporated into the filling. However, amalgam fillings do release extremely small amounts of mercury. The amount of mercury released is less than the amount of mercury you’d get from eating fish, but this does pose a problem for people with a mercury allergy.
At a news conference on July 29, 2009, a dentist, Dr. Susan Runner of the ’s Division of Anesthesiology, General Hospital, Infection Control and Dental Devices stated the following about dental amalgam:
“Patients are not at risk for long-term, mercury-related adverse health events.” She went on to add, “We’re not contraindicating dental amalgam in any patient group [other than those who have allergies].”
To summarize, amalgam has been used for over 180 years without any major problems. The only absolute contraindication for an amalgam filling would be a mercury allergy.
5 – Composite fillings may leak out Bisphenol-A. Bisphenol-A is a chemical that can be toxic in large enough doses. Discussion of this issue is outside the scope of this article, but I will refer you to a page on the Bisphenol-A website and a news article about bisphenol-A. I will say that based on current evidence, the amount of bisphenol-A released from a filling is unlikely to cause any harm.
6 – Amalgam fillings require the dentist to remove healthy tooth structure. Since amalgam fillings don’t bond to the tooth like composite fillings, the dentist has to make the filling wider at the bottom than it is at the top so that the tooth will hold the filling in place. In order to do this, the dentist usually has to cut away healthy tooth structure. With composite fillings, the dentist can simply remove the decay and then place the filling without cutting away healthy tooth structure to retain the filling.
7 – Composite fillings shrink when they harden. Most composite fillings get somewhere between 2-5% smaller when they harden. Sometimes this can lead to gaps between the filling and the tooth which allow bacteria to enter and start a new cavity. Other times, when a large composite filling shrinks as it hardens, it can put stress on the tooth which results in increased sensitivity of the affected tooth. The effect of the shrinkage can be minimized if the dentist adds the composite in small, incremental layers.
8 – Composite fillings are more technique-sensitive. This means that the dentist has to pay close attention to detail when placing a composite filling. As you’ll find out below, there are more steps that your dentist must follow precisely when filling your tooth with a white filling. For example, if your dentist doesn’t properly prepare the tooth with an etching solution for a specific amount of time, or if they do, but some of your saliva gets onto the tooth after it is etched, the filling may not attach to the tooth tightly and could end up leaking and ultimately needing to be replaced after only a year or two. Most dentists have lots of experience doing white fillings and will do a good job. As long as they are following the steps mentioned below for the composite filling procedure, the filling should last you a long time.
Hopefully the above section will help you figure out which type of filling will work best for you. Even if you are still uncertain, at least now you know what issues or concerns to further discuss with your dentist.