Teeth are very strong, but they can break, fracture, or chip. This usually occurs from getting hit in your mouth, eating something hard, or weakening of your teeth due to decay. A tooth does not necessarily have to hurt when it breaks, and may even go unnoticed. This usually depends upon the size of the break and the location on the tooth. If the underlying tooth surface, the dentine, or the pulp is injured and the tooth is exposed to saliva, air, chewing pressure, cold or hot beverages and foods, then pain may occur.
Plaque builds up on the teeth. Bacteria, which live in plaque, multiply.
The bacteria produce acids, which soften the enamel. Over time, a small hole known as a cavity can develop on the surface of the tooth.
Once cavities have formed in the enamel, the plaque and bacteria can reach the dentine. As the dentine is softer than the enamel, the process of tooth decay speeds up.
Without treatment, plaque and bacteria will enter the pulp. At this stage, your nerves will be exposed to bacteria, making your tooth very painful. The bacteria can also infect tissue within the pulp, causing a dental abscess.