“Doc, why do I need a filling if my tooth doesn’t hurt?”

At our office, we hear our patients tell us this on a weekly basis. The fact is that many times cavities are not painful. To understand this, we need to briefly look at what makes up a tooth and how a cavity forms.  There are different layers of the tooth – for simplicity we have a hard enamel outer layer, a softer dentin layer, and in the center are is the pulp containing blood vessels and nerve endings.


Cavity formation is usually a slow process by which bacteria that are found in the mouth produce acid which slowly dissolves the outer enamel of the tooth. Once the bacteria make it through the enamel, they begin dissolving the dentin layer of tooth. This layer has small ‘tubules’ that run throughout and have a relationship to the nerve endings in the middle of the tooth. At this point sometimes patients may feel some sensitivity, but not usually. Once bacteria have moved into the dentin decay proceeds much quicker due to the decreased hard mineral content. Only when the decay progresses and comes in close proximity to the pulp will you start to feel pain or increased sensitivity. Usually at this point the decay has progressed to a point where a large cavity has formed and now the nerves and blood vessels need to be removed- known as a ‘root canal’.


Many times we are able to diagnose cavities early on and restore the tooth before it becomes painful or destroys significant tooth structure. This is just another reason why it is very important to see your dentist at least twice a year so we can catch problem areas before they become more serious.

– Dr. Dan