What Causes Cavities?
Bacteria live in your mouth, and while some types are necessary and healthy, other types are not. Bacterial buildup on your teeth is called plaque. Plaque contains acids that can eat away at your tooth enamel if allowed to sit on teeth for too long. Eventually, once the acids penetrate the enamel, they begin to break down the next layer of the tooth ― the dentin ― until the decay spreads to the inner pulp.
Once the cavity has made its way to here, it starts to affect nerves and leads to pain and inflammation. At this point, a cavity can cause some discomfort. Fillings can both relieve pain and save your tooth from further damage.