The most common driver of acute tooth pain is dental decay (cavities). Bacteria in the mouth produce acids that erode enamel and, over time, penetrate deeper layers of the tooth, eventually irritating or infecting the nerve. Once bacteria reach the pulp — the soft inner tissue containing blood vessels and nerves — pain becomes intense and persistent.
Cracked or fractured teeth are another frequent culprit, particularly in adults who grind their teeth or have large older fillings. A crack that runs toward the root can cause sharp pain when biting, along with sensitivity to temperature. Abscesses — pockets of bacterial infection at the tooth root or in surrounding gum tissue — produce severe, throbbing pain and may be accompanied by swelling, fever, or a bad taste in the mouth. These are dental emergencies that require immediate care.
Other causes include gum disease, an exposed root from receding gums, a damaged or lost filling, an impacted wisdom tooth, or sinus pressure that mimics upper molar pain. Grinding (bruxism) and clenching can also create chronic soreness in multiple teeth simultaneously.
