Which Dental Fillings Are the Safest?

Which Dental Fillings Are the Safest?

It is natural for people to have questions about any substance that is put into their body, and dental fillings are no exception. Some publications have raised concerns about the materials used in some fillings. Is there any cause for concern? And if so, which dental fillings are safest?

The most recent research indicates that all fillings in current use are safe for patients. There are different reasons for getting different materials—but safety is not a concern for any of them. Still, it is a good idea to clarify what the research does, and does not, say.

What Different Types of Fillings Are Available?

Not all dental fillings are made of the same material. As dentistry has advanced, many materials for fillings have been tried and tested. Those in current use include:

Dental Amalgam. Dental amalgam fillings are composed of a mix of mercury, silver, tin, and copper. For a long time amalgam was the most widely used filling because of its durability and low cost. The downside is that it does not match the natural color of teeth. This is the kind of filling most people are concerned about, because of the presence of mercury—but it is important to note that this is not the same mercury that causes health concerns. 

Gold. Gold fillings are actually made of a composite of gold and other metals, such as nickel or chromium. Gold fillings are durable, lasting 10 to 15 years. But they can cost up to ten times more than amalgams and require two office visits. Also, some patients dislike the fact that gold does not match the other teeth.

Composites. Many patients prefer composite fillings because they come in different shades of white and so can match the color of teeth. They are used for chips and breakages for front teeth and other visible areas. They can cost twice as much as amalgams and do not last long, especially on back teeth, and require replacing every five years.

Ceramics and Porcelain. These fillings are designed to match surrounding teeth and resist staining more than composite fillings. They can last up to 25 years but can experience wear and tear or become chipped or cracked. Ceramic fillings are more resistant to stains and abrasions. They do not run the risk of developing micro cracks, as sometimes happens with amalgams, and which can lead to further decay with the sealed tooth.

Glass Ionomer.  These are made of a flexible paste and used as temporary fillings for baby teeth. They slowly release fluoride over time, helping to prevent future cavities. Negative effects include their lack of durability compared to composite and amalgam fillings. They are also used as temporary fillings in an adult mouth to prepare for later restorations.

There really is no question of which dental filling is “safest.” All of these fillings can be considered “safe,” and discussions with your dentist will determine which would be suitable. Factors such as age, manner of use, severity, and size of the cavity should be considered.

How Safe are Amalgam Fillings?

amalgam filling in a model mouth

While the FDA has approved all dental fillings, and consequently they are considered safe, many people have some concerns, especially given the publicity about mercury in amalgam fillings.

The controversy about the safety of mercury started in the 1970s, causing many patients to question their dentist. Some dentists and groups were claiming that the mercury in amalgam fillings was causing serious diseases, such as heart disease, multiple sclerosis, cancer, arthritis, Crohn’s disease, and more. There was even some anecdotal evidence that symptoms eased after fillings were removed from patients. However, it appears that these claims were made without any sort of research, and for the financial gain of just a few.

Since then, clinical studies have shown that mercury levels in people with amalgam fillings are well below the level where the mercury could cause health problems.

Not only that, but the kind of mercury used in amalgam fillings is of a wholly different type. The mercury that is toxic to humans is something known as “methylmercury.” This is also the kind of mercury sometimes found in fish, and which has lead to concerns about mercury in the environment. The mercury used in fillings is elemental mercury, which is quite different. This is the same mercury found in old-fashioned thermometers. This type of mercury will not cause mercury poisoning in humans.

All that said, some still advise caution. The FDA’s updated recommendation on dental amalgam, for example, state that exposure to mercury may pose a greater health risk to certain populations: 

  • Pregnant women
  • Nursing women.
  • Children, especially those that are under the age of six.
  • People with kidney problems.
  • People with pre-existing neurological conditions like multiple sclerosis, Parkinson’s, or Alzheimer’s.

The FDA suggests dentists use alternatives like resin and glass cement fillings for people in those vulnerable categories. It does not recommend that people remove or replace fillings in good condition. Removal can increase exposure to mercury vapor, not to mention it can hurt an otherwise healthy tooth structure.

Note that, after the FDA guidance was updated, the American Dental Association (ADA) said it “reaffirms its position that dental amalgam is a durable, safe and effective cavity-filling option.”

Can You Be Allergic to Dental Fillings?

Some people can be allergic to amalgam fillings. In rare cases, allergic reactions such as oral lesions, swelling, or rashes related to amalgam dental fillings have been reported. According to the ADA, this has happened in fewer than 100 cases. If you have any concerns about silver fillings, consult your dentist.

There are a number of people in the world who also have an allergy to gold. This seems to be more common in women.  For these people, the use of a gold filling is not advised, as it can cause rashes and eczema. 

There have been no confirmed cases of allergies to porcelain, resin, or glass fillings.

Other Issues with Dental Fillings

person holding iPad with an x-ray of a mouth with dental fillings

Tooth sensitivity is a concern whenever dental work is done on a patient. A tooth may be sensitive to pressure, air, sweet foods, or temperature. Having some sensitivity after a filling is quite common. Usually, the sensitivity resolves on its own within a few weeks.

Gold fillings can sometimes create more sensitivity than other types of fillings. Gold is a good conductor of heat/cold and of pressure— more so than other materials. Thus, teeth that are already sensitive might trigger more pain or discomfort with a gold filling.

In rare circumstances, a gold filling placed next to an amalgam can create a reaction between the two metals, causing pain and increasing saliva. This occurrence is called a “galvanic shock.” For this reason, it is best to choose the same kinds of fillings each time you need one.

The important thing to remember, though, is this: Do not ignore tooth pain. Pain is a signal that something is amiss in your mouth, and the quicker the cause is discovered, the sooner it can be addressed.