Should You Replace Old Amalgam Fillings?

Dr. Christopher Li Etobicoke - Li Family Dental

By Dr. Christopher Li

November 12, 2020

amalgam fillings, dental fillings, fillings

Dental fillings are used to fill cavities and prevent further decay from occurring. If you are over the age of 30, chances are if you have dental fillings, at least one is an amalgam filling. Amalgam was the filling material of choice for over 150 years. However, over time, concerns were raised that the mercury contained in amalgam fillings posed health risks. Because of the mercury content, many dental offices, including ours, no longer use them. The mercury can be released in exceedingly small amounts over time. Although this is the case, studies show the mercury content does not lead to illness.

However, considering the new filling materials that are available, amalgam no longer makes sense. Here we look at amalgam fillings and available replacements.

What Is A Filling?

Fillings are a common form of “restorative” treatment. They are used to fill cavities caused by tooth decay. To stop decay from causing further damage, the decayed tissue is first removed from the cavity and then the hole is filled. This stops bacteria from entering the tooth which prevents tooth decay from recurring. Many dentists today choose composite resin to fill cavities as it is the same colour as your teeth — but more importantly it provides a solid bond to improve the tooth structure.

What Are Amalgam Fillings?Amalgam-Fillings-Li-Family-Dental

Dental amalgam fillings are the most common filling used in Canada. However, with the advancements of new tooth-coloured resins, amalgam fillings are mainly used for back teeth where they are less noticeable. Amalgam fillings are made from different metals including mercury, silver, copper, and tin. They are the most affordable option, but are not offered in many dental offices anymore due to the potential health risks associated with the mercury content.

What Other Filling Materials Are Available?

Today there are many different types of fillings available, including:

  • Composite Resins: Composite resin has become the popular choice by both dentists and patients. They help maintain the natural look of your teeth and will last up to 10 years. However, they are not suited for exceptionally large cavities.
  • Inlays: Inlays are used for larger cavities in teeth with severe decay on the chewing surface. They are a pre-molded filling customized to fit the grooves of your existing tooth and are available in resin, gold, and porcelain materials.
  • Onlays: Onlays are like inlays, but are used when the decay damage extends beyond the chewing surface to the “cusps”. In these cases, the onlay is more noticeable and therefore resin or porcelain is better suited, as opposed to gold.

These filling options are preferable over amalgam because they last longer, do not contain mercury, and match the colour of your teeth.

Composite Fillings Add Strength

As mentioned, composite fillings bond to the tooth while filling in the cavity. This provides added protection that helps strengthen the tooth. While the composite becomes one with your tooth, this is not the case for amalgam fillings, which leave the remaining tooth vulnerable to pressure and potential damage. While composite renews and strengthens your tooth, amalgam simply “plugs” the cavity. This makes it more susceptible to damage such as cracks and fractures. This is another good reason to consider replacing your amalgam fillings.

Amalgam Fillings Allow DecayTooth-Decay-Under-Amalgam-Fillings-Etobicoke-Dentist

As mentioned, amalgam fillings are not bonded to your teeth like composite resins. As a result, they can allow the tooth surface below the filling to wear down over time. Amalgam fillings should be replaced within or before 10 years. Because they are prone to becoming loose, they can allow decay to form beneath the filling. This can be hard to detect, especially if you don’t attend your regular dental checkups.

The longer the decay remains undetected, the more harm can be done to your tooth. This can lead to costly restorations such as crowns, or it can even penetrate the root, requiring a root canal. When the root is affected, the infection can be dangerous and painful. At your routine dental exams, we check for signs it’s time for a replacement. However, to avoid issues, you might consider having your amalgam fillings replaced as a preventative measure.

Amalgam Fillings Expand And Contract

When you consume hot or cold drinks and food, the metal of amalgam fillings responds to the changing temperatures. Mercury is particularly responsive to temperatures which means your filling can expand and contract as temperatures in your mouth change. This places strain on your tooth when the pressure of the expansion is too much to bear. Too much pressure leads to fractures. In the case of cold beverages or foods like ice cream, the metal shrinks, which can lead to loosening of the filling. This leaves gaps that are vulnerable to decay, not to mention the possibility of the filling falling out.

Amalgam Fillings Are Obvious

The dark metal of amalgam fillings makes them far more obvious than their tooth-coloured resin  counterparts. When you smile, open your mouth, or laugh, the dark fillings can ruin the appearance of your teeth. This is one of the reasons many patients choose to replace their amalgam fillings with composite. They are invisible and blend perfectly with your natural tooth colour.

Why Old Fillings Should Be Replaced

Replacing old fillings is part of your preventative dental care regime. Just as we check for signs of decay at your regular dental checkups, we also check the condition of existing fillings and other restoratives such as crowns, inlays and onlays. We look for several different signs that it is time to replace a filling, including:Replace-Amalgam-Fillings-Li-Family-Dental

  • Your old amalgam fillings contain mercury
  • A filling has chips or cracks
  • Your fillings have become loose
  • There are signs of decay beneath the filling
  • The filling shows signs of discolouration
  • You are experiencing pain or sensitivity around a filling

It is important to inform us of any pain or sensitivity so we can examine the area to determine the cause.

While some dentists continue to use amalgam fillings, composite resin is the filling of choice at Li Family Dental. If you have old amalgam fillings or are looking to have fillings that match the natural colour of your teeth, call 416-232-2033 or request an appointment by clicking here.

Dr. Christopher Li

About the author

Doctor Christopher Li, DDS
Dr. Chris, as he is affectionately known, is a licensed dentist with over 20 years experience. His caring personality makes even the most tentative person at ease. Patients are constantly commenting about how Dr. Chris is incredible at delivering pain-free freezing, and how he has an amazing chair-side manner.  Dr. Chris loves sharing information with his patients and everyone who has teeth about how to care for their teeth, avoid tooth decay, and the treatments available to help them overcome their tooth pain or other dental issues so they can enjoy life and food to its fullest!

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