If a large piece of the tooth breaks off, it can hurt because the nerve inside the tooth may be damaged. If the nerve inside the tooth is exposed to air, saliva, or hot or cold foods or drinks, it can be extremely uncomfortable.

When a tooth cracks or fractures, it may or may not hurt. You may not notice the damage immediately. Minor tooth fractures are unlikely to cause symptoms. Deeper fractures can be painful because the damage may extend to the nerve inside the tooth. Pain from fractures may be constant or may come and go. Many people feel pain when they chew because as they chew they apply pressure to the tooth. As the fractured tooth bites down on the food, the crack in the tooth gets wider, but once the pressure is released, the crack closes again.

Larger fractures may cause a portion of the tooth to break off.

What You Can Do

Fractured Teeth
There is no way to treat fractured teeth at home. You need to see your dentist whenever a tooth is sensitive to changes in temperature or if it hurts while you're eating. Pain that's constant is a serious warning sign because it may mean that a fracture has damaged the nerve and live tissues inside the tooth.

Broken Teeth
You'll want to see your dentist as soon as possible. Your dentist will need to determine if the break was caused by decay and if the nerve is in danger. Adults with a damaged nerve usually will require root canal treatment, but in children, there's a possibility the nerve can be saved if the dentist is able to treat the problem immediately.

In the meantime:

• Save the pieces. If the break was relatively clean, your dentist may be able to cement the tooth back together as a temporary measure.
• Rinse your mouth well with warm water. If you were able to save the tooth fragments), rinse them under running water.
• If an area is bleeding, apply a piece of gauze to the area for about 10 minutes or until the bleeding stops.
• Apply a cold compress to the cheek or lips over the broken tooth. This will help reduce swelling and relieve pain.
• If you can't get to your dentist right away, cover the broken surface of the tooth that is in your mouth with temporary dental cement, available in pharmacies.
• Take an over-the-counter pain reliever.

What Your Dentist Will Do

Fractured Teeth
There are several types of tooth fractures, each of which requires different treatments. These include:

• Minor cracks — Also called "craze lines," these are superficial fractures that affect only the tooth's enamel, the outer white part of the tooth. Minor cracks rarely need treatment. However, your dentist may lightly polish the area to smooth out any rough spots.
• Chips — Minor chips don't always need treatment, although your dentist may recommend repairing the damage with filling material to prevent it from getting worse or to make the tooth look better. If the chip is in the front of the mouth, your dentist probably will use a tooth-colored filling. Often, if the chip is very small, your dentist may lightly sand the area to smooth out any rough spots.
• Cusp fractures — These affect the pointed chewing surfaces (the cusps) of the teeth. They usually do not affect the pulp and are unlikely to cause significant pain. They may interfere with normal chewing, however, so your dentist may need to repair the damage. Minor cusp fractures sometimes are repaired by filing the surfaces of the tooth to restore the shape of the tooth. Frequently, these fractures will require an onlay or crown, in which the tooth is covered with a metal or porcelain material.
• Serious fractures — These are fractures of the teeth that are deep enough to expose the nerve tissue. Usually, the broken part of the tooth will bleed. They almost always cause the tooth to hurt and be sensitive. This type of fracture will require root canal treatment to remove the exposed nerve. A crown likely will be needed to restore the tooth.
• Cracked tooth — This type of fracture involves the whole tooth, from the chewing surface all the way down toward the nerve. However, in this type of fracture the two pieces have not come apart. This type of crack is similar to a crack that may form in an automobile windshield; the pieces remain in place, but the crack gradually spreads. Cracks can sometimes be repaired with filling material, although the tooth often will need a crown to prevent the crack from getting worse. If the pulp (nerve and other live tissues) is damaged, you may need a root canal as well.
• Split tooth — This means that the tooth has split vertically into two separate parts. Some teeth, such as your back teeth (molars), have more than one root. It may be possible to keep one of the roots, which will then be covered with a crown. First, root canal treatment will be needed. Second, the root or roots that will not be kept are removed with a minor surgical procedure. Third, a crown will be made to cover the root and replace the tooth. Often, however, the tooth will have to be extracted.
• Vertical tooth fractures or split root — These are cracks that start in the root of the tooth and extend upward toward the chewing surface. Vertical tooth fractures are often painful because the tissues surrounding the root may be inflamed or infected. In most cases, the tooth will have to be removed.
• Decay-induced fracture — In this case, the tooth has fractured or crumbled because a cavity weakened the tooth from the inside out. Your dentist will evaluate the cavity and recommend the best way to restore the tooth.

Broken Teeth
There are many possible treatments for broken teeth, depending on the severity of the break.

If the break affected only the outer part of the tooth (the enamel), your dentist may be able to repair the damage with a filling. If the tooth is in the front of the mouth, your dentist probably will use a composite (tooth-colored) filling.

A more serious break will involve the enamel as well as the inner layer of the tooth (the dentin). In some cases, the damage can be repaired with a filling, but often the tooth will need a crown.

The most serious breaks are those that damage the nerve. In addition to making and placing a crown, your dentist probably will need to do root canal treatment to remove the damaged nerve and blood vessels.

Some fractures will require periodontal surgery before a crown can be placed. If the facture is below the gum line, close to or below the bone holding the tooth in the jaw, periodontal surgery will be needed to remove some bone to create enough room to place the crown over the root properly.