When you break a tooth, the hard outer layers crack open and expose the softer, more sensitive structures underneath. Depending on how deep the break goes, you might feel nothing at all or experience sharp, immediate pain. What happens next, both inside the tooth and in terms of treatment, depends entirely on the severity of the fracture.
Why a Broken Tooth Hurts
Your teeth have three main layers. The outermost layer, enamel, has no nerve endings and can chip without causing pain. Beneath that is dentin, a porous layer that transmits sensation. At the center is the pulp, a soft chamber filled with blood vessels and nerves that detect temperature and pressure changes.
A minor chip that stays within the enamel often causes no pain at all. But when a break reaches the dentin, you’ll likely notice sensitivity to hot, cold, or sweet foods. If the fracture goes deep enough to expose the pulp, bacteria from your mouth invade almost immediately. The pulp becomes inflamed, and that inflammation is what produces the throbbing, persistent toothache most people associate with a broken tooth. Left alone, the nerve inside the tooth can die, and infection can begin spreading toward the root tip.
What to Do Right Away
If you’ve knocked a tooth completely out, handle it only by the crown (the white part you normally see) and never touch the root. Don’t wrap it in tissue, which damages the root surface. Instead, gently rinse it with milk or your own saliva, not tap water, since tap water kills the cells that help reattach the tooth. Try placing it back in the socket and bite down gently on gauze to hold it in place. Then get to a dentist or emergency room as fast as possible.
For a partial break or crack, rinse your mouth with warm water and apply a cold compress to your cheek to reduce swelling. If you can find the broken fragment, store it in milk. Over-the-counter pain relievers can help manage discomfort until you’re seen. Avoid chewing on that side and skip extremely hot or cold foods and drinks, which will trigger the exposed dentin.
How Dentists Find the Damage
Not every crack is visible to the naked eye. Hairline fractures in particular can cause persistent pain without any obvious break. Dentists use several techniques to track them down.
A bite test is one of the most common. You’ll be asked to bite down on a cotton roll or a small plastic tool placed on each cusp of the tooth individually, then release suddenly. Pain on biting or on releasing pressure pinpoints the cracked cusp. Your dentist may also shine a fiber-optic light directly through the tooth, a technique called transillumination. A crack in the dentin disrupts the light, making the fracture line visible. Periodontal probing, where a thin instrument is slid along the gum line, can reveal whether a crack has extended below the gums. An isolated deep pocket around one tooth is a red flag that the fracture runs deep.
Repair Options by Severity
Treatment scales with the damage. A small chip that stays in the enamel can be smoothed down or repaired with dental bonding, where tooth-colored resin is applied directly to fill the gap. This is the simplest and least expensive fix.
For front teeth with cosmetic damage, a veneer (a thin porcelain shell bonded over the tooth’s surface) restores the appearance. When a larger portion of the tooth is missing or the structure is weakened, a dental crown caps the entire tooth. Crowns come in several materials: metal runs $500 to $1,500 per tooth, porcelain fused to metal costs $600 to $1,800, and all-ceramic crowns range from $800 to $2,000.
If the crack has reached the pulp, a root canal is typically necessary before placing a crown. During a root canal, the infected or damaged pulp is removed, the interior is cleaned and sealed, and a crown is placed on top to protect the remaining structure. Root canal costs vary by tooth: $500 to $1,000 for a front tooth, $800 to $1,500 for a molar.
When a Tooth Can’t Be Saved
Some fractures run too deep for repair. A crack that extends well below the gum line into the root has a poor prognosis. Periodontal probing depths of 5 millimeters or more around the fracture site are associated with significantly reduced survival rates. Cracks that pass beyond the entrance of the root canal are historically considered unfavorable for treatment. In these cases, extraction is the more predictable option, followed by replacement with an implant, bridge, or partial denture.
A tooth that splits completely in two, where the crack runs from the chewing surface all the way through the root, is almost always non-restorable. Your dentist will distinguish between a cracked tooth (which may still be treatable) and a true split tooth (which generally needs to come out) based on probing, imaging, and how far the fracture has traveled.
Long-Term Outlook for Repaired Teeth
A cracked tooth that receives a root canal and a full crown has a strong chance of lasting. Research tracking cracked teeth after endodontic treatment found an overall survival rate of 68% at five years and 54% at ten years. But those numbers shift dramatically based on the type of restoration placed afterward. Cracked teeth restored with a full crown after root canal treatment had a 97% survival rate, compared to much lower rates for teeth repaired with only a composite filling. The crown essentially holds the tooth together and prevents the crack from spreading further under chewing forces.
What Happens If You Ignore It
A broken tooth that doesn’t hurt right away can still deteriorate. Bacteria steadily work their way through even a small crack into the pulp. Once the pulp is infected, the tissue dies and the infection moves to the tip of the root, forming a periapical abscess: a pocket of pus at the base of the tooth. Symptoms include persistent throbbing pain, swelling in the face or jaw, fever, and a bad taste in the mouth from draining pus.
A tooth abscess is not something that resolves on its own. Without treatment, the infection can spread into the jaw, neck, or throat. Difficulty breathing or swallowing alongside facial swelling is a medical emergency. These are rare outcomes, but they underscore why even a painless crack deserves a dental evaluation. The earlier a fracture is treated, the more of the tooth can be preserved and the simpler the repair tends to be.