Dental MythBuster #13: A Dental Filling Will Last Forever

Fortunately, this dental myth does not come up very often. When it does, the myth usually comes up when I have to deliver news along the lines of “I have a concern about one of your fillings.”

Most patients understand that dental fillings are usually not lifelong permanent solutions. But some patients don’t. Like many other medical devices and appliances, fillings don’t last forever.

Problems with Dental Fillings

There are all types of problems that can occur with dental filings. Below are some examples:

broken mercury amalgam filling in a tooth

A broken silver amalgam filling. This will need to be replaced.

The tooth above shows two premolar teeth, both with amalgam fillings. One of the fillings has cracked. There are many reasons why it cracked – but they go beyond the scope of this post. However, to summarize, after being chewed upon several hundred thousand times, it has finally failed.

high quality photo of broken lower molar tooth with a filling

Here, both filling and tooth broke!

In this photo, a large portion of both tooth and filling broke. In this particular case, the filling had been there for over 20 years, but the remaining tooth structure was so weak it finally gave out. In this case, this patient needed a crown.

In addition to the above two examples, dental fillings can fail for many other reasons. And many will fail due to a combination of multiple factors.

What other medical appliances last a lifetime?

On occasion, I will come across a patient who is particularly disturbed that one of their fillings done during the Clinton presidency needs to be replaced. I will often politely respond by referencing other medical appliances:

cardiac pacemaker is like a filling and can last seven years

On average a pacemaker lasts seven years.

What do the above 3 devices all have in common? These are all manmade devices designed to replace or repair damaged or missing human tissue. And that is exactly what a filling is.

When I mention these examples, most patients begin to understand fillings typically have a finite lifespan. And then the myth is busted…

How Long Should a Filling Last?

This is difficult to answer since there are so many factors at play. I’ve seen fillings last over 40 years while others fail within 1 to 2 years. The factors can include:

  • Type of material (silver amalgam vs. resin composite).
  • Location in the mouth.
  • Oral hygiene.
  • Sugar intake.
  • Occlusion (how the teeth come together).
  • Skill level and attention to detail of the dentist who placed it.

So, while occasionally a filling can last a lifetime, that is not the norm. Just like nearly all other medical appliances and devices, they can and do wear out. It is a myth that all fillings will last forever.


  1. Olivia Gilman says

    I think that people often think that a filling will last forever. So, when the filling has a problem or comes out, we are disappointed and feel wronged. Thanks for letting us know about the different parameters that affect the life expectancy of a filing. I thought it was really interesting that sugar intake is a factor. Good to know!

  2. I have to admit that I hadn’t really ever thought about the lifespan of a filling, but I would have assumed it was always possible to have future problems with a filling. The image of the tooth that broke WITH the filling reminded me of my childhood. I had a portion of my tooth separate like that, but there was no pain. Luckily, it was a baby tooth, so we could just remove it instead of getting a crown.

  3. I have over 19 fillings in my teeth and 3 pulled molars. I acquired a phobia of dentistry as a kid and did not go to the dentist until I was about 30. Even an x-Ray hurt me because I had so many cavities and I have a big overjet, so it’s hard for me to bite down. I can only make contact on 3 teeth in my mouth, but I don’t have $6,000 for braces. There are no dental subsidiaries or grants for someone over the age of 25, so it’s important for me to keep the teeth I have left. I’m a gentile brusher and a diligent wax flosser. I’m thinking about putting one crown at a time on Care Credit because I’ve used them before for a loan and didn’t have a problem.

    I’ve had 2 perfect cleaning check-ups, but my dentist warns me that I need to start replacing my larger fillings with crowns. Today, I noticed that there is a small black spot in the center of some of my teeth. I’m not sure if these teeth are filling teeth or not. I do know that the spots weren’t there before. I am very susceptible to calcium buildup on the back of my front teeth. Could these spots be a type of calcium or stain? They’re in the deepest crevice and very small. Is it possible my brush didn’t reach the particles? Eww! i have a six month cleaning in August. Should I bother my dentist now (July) or just wait until my scheduled cleaning?

  4. Interesting article. I was among those people who were not thinking about lifespan of filling – until recently. I had 14 fillings done when I was child / teen 25-30 years ago. They have all been fine until recently. One filling simply fell out of the tooth because the filling was undermined by new decay round and under the filling. Just a few weeks later a large part of another tooth broke off while I was chewing some soft bread. The filling looked fine to me but my dentist told me that the filling had weakened my tooth so it could stand chewing pressure any longer. Result: two root canals and two crowns. So, I have learned from experience that I should be concerned about my fillings and have them replaced in near future to avoid any more damages.

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