A large cavity in a tooth
This is a very common cause of tooth pain. If you experience toothache or teeth sensitivity after eating, it can be due to tooth decay [1] or cavity. Having a large cavity can cause you to experience tooth pain after eating some types of food. A cavity in most people can cause tooth sensitivity. Although, you can also feel a lingering pain in your tooth when you consume sweets. It may also be a case of getting food stuck in large cavities [2], resulting in the exertion of extra pressure when you chew and causing pain.
You may also start to feel pain in your tooth when a cavity filling falls out as a result of extra pressure in the area and food starts to get stuck in the area. This can also cause teeth sensitivity when you bite down. If you have tooth decay, you will feel severe toothache when you chew or bite down food. Tooth decay can also irritate your pulp (tooth nerve).
However, you need to know that not all cavities hurt. Immediately contact your doctor if you feel any strange sensation when you bite down.