13 Dec
Cracked Tooth Due to Large Amalgam Filling

Fractured Teeth Symptoms and Treatment Options

Cracked teeth are one of the most common dental conditions of the modern day. And while dental cavities and gum disease are far more prevalent, cracked teeth are becoming more frequent due to the increased incidence of tooth grinding and clenching. You may have a cracked tooth if you experience pain and discomfort on chewing, temperature sensitivity, gum swelling and/or infection.

Oral health consequences of an untreated cracked tooth

See what can happen if cracked tooth is left untreated.

Why Do Teeth Crack?

Teeth have certain elasticity to bend and flex and absorb forces, but once a crack becomes too deep, even chewing on a piece of soft bread can break a cusp off. The reasons behind tooth cracks are multiple and some of the most common ones are:

Dental Trauma

A hit or a fall can certainly provide the force to break off a cusp, or split a tooth, but trauma can be more subtle that than. Frequently chewing on ice, and eating hard foods, like popcorn kernels will propagate already existing craze lines or tooth cracks.

Large Restorations

Dental fillings put teeth at a 29 times greater risk for cracks. This is especially true for silver amalgam restorations that are oversized and leave the tooth cusps thin, weak and prone to fracture. A general rule of thumb is: if the width of the filling will exceed 1/3-1/2 of the width of the tooth, then the tooth needs to be crowned in order to prevent a fracture.

Tooth Cracks Caused By Failed Large Amalgam Fillings

See how an aging amalgam filling can cause cracks in posterior teeth.

Bite Alignment

Teeth that are mal-aligned are more prone to cracks, fractures and wear. Well aligned bite is protective of the teeth because the forces of the bite are received and dispersed evenly. When teeth are crowded, rotated and misaligned, the bite forces are transmitted obliquely and off axis producing trauma to the tooth and the surrounding tissues.

Clenching and Grinding

The forces generated on teeth during these habits far exceed chewing forces people can generate while chewing. Research shows that humans with natural dentition can generate forces of up to 150 PSI (pounds per square inch), while denture patients have much less chewing ability of 50 PSI. In contrast, we can generate monster forces during subconscious bruxing of 900-1000 PSI.

How Do I Know If My Tooth Is Cracked?

The symptoms depend on the extent of the crack. Some cracks are completely asymptomatic, while others can hurt on biting down. As the crack progresses it may cause constant discomfort, infection and swelling. If you suspect you have a cracked tooth, please contact your dentist, as the prognosis of the treatment is more predictable in the earlier stages of crack development.

Diagram showing how fractured tooth can become a split tooth

What Are the Different Types of Tooth Fractures?

Not all tooth cracks are created equal. Typically, there are five types of cracked teeth. These are:

Craze Lines

Craze lines are superficial, hairline cracks confined to the enamel (the outer layer of the tooth). They are typically symptom free and commonly found on anterior teeth. They most likely will not require treatment, but need to be monitored for crack propagation, especially if the patient tends to clench and grind their teeth.

Cracked Tooth

Tooth cracks are fractures without complete separation of parts. Tooth cracks will leak and allow for percolation of saliva and bacteria that will eventually stain the crack, so newer cracks are unstained, and as the crack ages it becomes stained and more visible. There may or may not be any symptoms associated with the tooth at this stage, and this depends on the depth of the crack. Superficial cracks are asymptomatic, and as they propagate deeper, they will cause pain on chewing.

Treatable cracked tooth

Fractured Cusp

Fractured cusps are breaking or parting so that parts of the whole become separate. This happens when a crack is running obliquely or at an angle (not through the middle of the tooth) and involves breaking off of a cusp. Typically, this is a consequence of a crack becoming deeper. Cusps can break off above or below the gum line and this will have an impact on how the tooth can be restored.

Cracked tooth - treatable fractured cusp over white background

Split Tooth

Split tooth is a result of a crack that is running down the root surface of the tooth and splits the tooth in two parts. Frequently these cracks go down the middle of the tooth and are the result of the long-term progression of a cracked tooth. A split tooth is rarely salvageable.

3d render of split tooth

Vertical Root Fracture

Vertical root fractures involve the roots of the tooth and may be unnoticed until the tooth gets infected. They are frequently untreatable and have poor prognosis.

Vertical Fracture of a Tooth Root

How Is A Cracked Tooth Treated?

The treatment of cracks will depend on the extent and symptoms of a crack.

Craze lines usually don't need treatment especially if they are not associated with an existing filling on the tooth. Often times a small bite adjustment and monitoring of the tooth is sufficient.

Smaller cracks that are asymptomatic can be removed and restored by a composite filling. If a crack was caused by an already existing, larger filling, then a crown is placed on the tooth in order to contain the crack and prevent it from further deepening. A crown provides a solid shell that splints the tooth together and helps contain the crack.

If a crack was symptomatic, then it may have come too close to the tooth nerve and a root canal is often the treatment of choice in addition to a crown.

When a fractured cusp breaks off below the gumline, close to the neck of the tooth, sometimes a gum surgery, known as crown lengthening surgery, is needed in order to expose the fracture line.

Vertical root fractures and split teeth have unfavorable prognosis, and the teeth may need extraction.

How Can I Prevent My Teeth From Cracking?

While cracks cannot be treated at home, you can take steps to prevent them.

Keep your teeth healthy and strong, maintain regular dental checkups, and wear a bite guard if you grind your teeth.

Discuss your options for aligning your bite with your dentist and take steps proactively treat teeth that show early signs of cracks. Don't wait for symptoms. Proactive dental care is more predictable and has a better long-term prognosis than waiting for a tooth to bother you.

And don't forget to stop using your teeth as tools!

Girl using her teeth as tool to crack a walnut

Think you may have a cracked tooth?

If you feel any kind of pain or discomfort when biting on food or drinking hot or cold drinks, you can schedule an appointment online or give us a call so we can have a closer look and diagnose your dental problem. The earlier you have a dentist take care of a cracked tooth, the better the chances of saving the tooth and preventing infection or the need for urgent or costly dental treatment in the future.


Heni Tufa

Dr. Tufa is a general dentist in Acton, MA who is also an Invisalign Provider and certified Botox dentist.