Tooth decay is the primary cause of tooth pain for most children and adults. Bacteria that live in your mouth thrive on the sugars and starches in the food you eat. These bacteria form a sticky plaque that clings to the surface of your teeth.
Acids produced by the bacteria in plaque can eat through the hard, white coating on the outside of your teeth (enamel), creating a cavity. The first sign of decay may be a sensation of pain when you eat something sweet, very cold or very hot. Sometimes decay will show as a brown or white spot on the tooth.
Other causes of a tooth pain can include:
1. An accumulation of food and debris between your teeth, especially if your teeth have spaces between them
2. Inflammation or infection at the root of the tooth or in the gums
3. Trauma to the tooth, including injury or grinding your teeth
4. Sudden fracture of the tooth or tooth root
5. A split in the tooth that occurs over time
6. Teeth that start to appear (erupt) through the gums, such as with teething or wisdom teeth that don’t have enough room to emerge or develop normally (impacted wisdom teeth)
7. A sinus infection that can be felt as pain in the teeth