X-Ray Example of an Amalgam Filling and Tooth Decay

The Bright White Spot is an Amalgam Filling. There is Significant Decay Next to the Filling.

I recently had someone ask me to evaluate an x-ray taken by another dentist. As you can see (in the image posted below), there’s clearly an amalgam filling (the bright white spot). You can also clearly see the cavity just to the left of the filling. What you can’t clearly see is what decay is developing below the mercury filling. That’s one of the problems with traditional x-rays.

You can’t see small decay on radiographs.  By the time you see it (as with the decay in this particular image), the decay is large.  X-rays really only see minerals, so only when the tooth has been decayed to the point there are no minerals, then the x-rays will look different.  Waiting until that happens results in more pain and possible extractions (or root canals if you go to a dentist that believes in those).

CT Scans will more clearly show decay under the filling and other small areas of decay (and the patient isn’t exposed to the large quantities of radiation an x-ray produces).

However, based on the decay next to the amalgam filling, and because decay under a poorly placed amalgam filling is very common, there is an above average chance that there is currently decay under the filling, as well.

What else can this one image tell us? Because there’s a large cavity in the tooth beside the silver filling, the patient probably has a diet that is conducive to decay (acidic carb diet). To reduce the chances of future decay, changing to a diet that’s lower in acid (water such as Essentia can help: Essentia Water Review), rinsing your mouth regularly after eating, and adhering to a proper dental care regimen can make a world of difference.

Dr. Marvin

PS: Thanks to the patient for allowing me to reprint this image and show a good example of decay around an amalgam filling. If you have particular questions about the x-ray, please leave a comment and I’ll do my best to get you a good answer.

The Bright White Spot is an Amalgam Filling. There is Significant Decay Next to the Filling.

The Bright White Spot is an Amalgam Filling. There is Significant Decay Next to the Filling.



  1. Alaa Eddin Says: May 25, 2017 at 3:41 am

    Thanks for your description. I wonder if there is also caries on the upper second premolar (25)? It looks like a manifest caries on the distal side of the tooth. Also there is an initial caries on the distal and mesial side of the first upper premolar (24).

    I hope you correct my comment if it is wrong.

  2. I paid to get amalgam taken out of my mouth. While doing it the dentist said there was a lot of it in my back molars and was it okay to put caps on them. I didn’t want the amalgam so whatever it took I was willing. Many years later now one of the back caps broke off and there is a blackish looking film on top. I don’t know if this is decay or perhaps he didn’t take out all the amalgam. I tried to communicate with him but he is not communicating. I am not sure what to do. Should I have the back molars pulled? There is no pain.

  3. Letitia Wolf Says: November 30, 2009 at 6:12 pm

    My son just lost a cap??? It was all silver and molded over the original toothe. Now it goes flush with the rest of the teeth. Basically he looks like the tooth was just cut off at the gumline. Was this a cap or not.

  4. thanks doc for the great case report, but i only want to ask about the coast of ct in this case (we are not used to use ct with dental caries here in Egypt) and if it was a high coast won’t it be better to remove the amalgam on the basis of history and examination.

    • Glad you liked it.

      CT Scans or CAT scans are not used for caries detection. It is used more for looking at infections around roots of teeth, sinuses, nerves, cavitations, and other problems (cancers for instance).

      We have worked out a deal with an imaging center to keep costs down. I don’t think we’ve ever had a patient not be intrigued with what we find when we show them their CT CAT scans.

      Cost for diagnostics is always an issue. But we can avoid serious (and sometimes costly and painful) health concerns, it makes complete sense to do whatever it takes to get a correct diagnosis and treatment plan.

      Don’t get me started on amalgam mercury fillings! You don’t need a CT CAT scan to reason to remove mercury fillings.

      Dr. Marvin

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