Tooth pain when biting down has several possible causes, including decay or a cavity, a crack in a tooth, or a loose filling, according to the American Society of Endodontists. With any sharp pain, one should see a dentist immediately for an evaluation of the problem.
The Dentistry IQ Network states that unpopped popcorn kernels and ice chewing are the most common culprits when a tooth cracks. This problem can be difficult to diagnose, because X-rays frequently do not show cracks. If the problem is pulp damage, the dentist may send the patient to an endodontist, a specialist who removes damaged pulp, cleans and reseals the tooth. This procedure is called a root canal.