If I don’t treat a cavity, what could happen

Left untreated, cavities will get bigger. The larger the cavity is, the faster it increases in size. Click here to learn more about different stages of cavities. As cavities get bigger, more of the tooth has to be removed in order to clean it. A filling can replace the tooth structure removed, but it is not the same as your original tooth. The bigger the final filling, the weaker the tooth becomes. As the tooth becomes weaker, the chance of fracture increases, and a dental crown may be needed.

As cavities get bigger, the chance of needing a root canal also increases. As more and more bacteria gets close to the tooth’s nerve, it becomes irritated and inflamed, swelling and increasing sensitivity. However, there is no room to swell because the tooth is a hard structure, and this leads to toothaches.

Drilling cavities is also traumatic to the nerve. If the cavity is too big, you may need a root canal even if the tooth doesn’t hurt. Click here to learn more: If I don’t get a root canal, what could happen?

If the cavity is allowed to get even bigger, it may reach a point where the only option is to extract the tooth. At this point, a chronic infection is typically present, which can affect other areas of your body.


Here you can see the progression of a medium sized cavity. The left x-ray shows a medium sized cavity (tooth #31; needs a filling). The right x-ray shows the same tooth after 14 months. Tooth #31 now needs a root canal, build-up, and crown.



Here you can see the progression of medium and large cavities. The top 2 x-rays show a medium cavity (tooth #3; needs a filling) and large cavity (tooth #4; needs a root canal, build-up, and crown).

The bottom 2 x-rays show the same teeth after 15 months. Tooth #3 now needs a root canal, build-up and crown. Tooth #4 has a poor prognosis and should be extracted.

Scroll to Top