What is a cracked tooth?

A cracked or broken tooth describes either an incomplete fracture (beginning on the surface of the enamel/root and terminating within the tooth) or a complete fracture (separating a portion of crown where the fracture occurs horizontally, or resulting in a ‘split tooth’ where the fracture occurs vertically). Treatments are available for cracked/broken teeth.

What is ‘Cracked Tooth Syndrome’?

Cracked Tooth Syndrome (CTS) occurs where a patient reports inconsistent symptoms of a cracked tooth, therefore likely caused by a fracture of unknown dimensions (i.e. unknown position, depth,  and direction of the fracture plane). This means that although the tooth appears to be whole, the unidentified fracture may have propagated further into the tooth.

The inconsistent symptoms linked to cases of CTS include intermittent ‘rebound pain’ felt when the jaw is released from a bite, occasional sharp pains in response to hot/cold drinks, and also a lack of full sensation in response to pressure and heat. Confusion over which tooth is causing CTS is also possible, with some patients reporting difficulty in determining the locus of pain. 

CTS is also known as a greenstick fracture. This is because of the similarity between the appearance of a fractured tooth and the appearance of splintered newly-grown ‘green’ wood.  

Causes of cracked teeth

The most common cause of a cracked or broken tooth is dental trauma (where the tooth receives a jarring blow as a result of contact with a hard surface). However, symptoms of pain or sensitivity in the jaw, gum, or teeth, may be the result of a cracked or broken tooth despite a lack of any notable instance of dental trauma. Some of these scenarios are outlined below.  Causes of cracked teeth include….

  • Excessive biting force when chewing food – An excessive biting force when eating can result in a cracked or broken tooth, either due to a singular impactful event or manifesting over time as a cumulative stress fracture.
  • Teeth grinding over time  – Patients may crack or break teeth as a result of grinding. This typically takes place while sleeping, but could also occur during waking hours as a habitual response to stress.
  • Filling size is a risk relating to Cracked Tooth Syndrome (CTS) – On average, fillings in back teeth can last 8-10 years. If more than 50% of the tooth is replaced with filling, the strength of the tooth can be dramatically affected. The remaining tooth structure can bend and flex under the loading of biting and grinding and over time (fracture lines and cracks can also develop as the tooth weakens).

The patient’s age also plays a considerable role in the likelihood of experiencing a cracked or broken tooth. With increased age comes an increase in overall exposure to knocks and biting pressures. The aggregate effect of these forces can weaken the structural integrity of the teeth. Patients in the 50+ years bracket account for the majority of cases for cracked/broken teeth.

Types of cracked teeth

Patients may be affected by cracked or broken teeth in one of three different ways: the issue may be isolated to the portion of tooth that sits above the gumline (the crown), the issue may be isolated to the portion of tooth that sits below the gumline (the root), or the issue may extend across both the crown and the root. These issues are further categorised below…

  • Craze lines – Craze lines are minor fractures in the tooth enamel. This type of fracture does not typically result in pain and the patient is unlikely to require treatment at this stage. 
  • Chipped tooth – The dentist may choose to polish and smooth over a chipped area, or a filling may be used in cases of slightly bigger chips to prevent any further loss of enamel. 
  • Fractured or broken cusp – The cusp of the tooth is located at the tooth’s peak – or chewing surface – meaning the canine teeth possess one cusp whereas the rear molars may possess as many as five. Restoration of a fractured or broken cusp may involve a crown or overlay.
  • Serious breaks – A serious break occurs where the fracture penetrates to the tooth’s nerve, causing significant pain (and sometimes bleeding). The course of restorative action most likely to be taken by the dentist is root canal and crown work.
  • Split tooth – A split tooth occurs where a complete vertical fracture divides the tooth into separate parts (in the case of rear molars, this would typically result in a bisected crown, with both sections attached to a root). Depending on a case-by-case analysis of circumstances, one or both parts of the split tooth may need to be removed (this means that restorative work will be case specific and may involve dental implants or bridge work, for example). 

How is a cracked tooth diagnosed?

Patients that experience symptoms suggestive of having suffered a cracked tooth are advised to visit the dentist as soon as possible – the dentist may be able to carry out restorative work to prevent any further damage to the tooth (ultimately helping to avoid eventual tooth loss). The dentist may diagnose a cracked tooth using any of the methods outlined below…

  • The dentist will ask the patient to describe the symptoms – The first step in diagnosing a cracked tooth is an analysis of symptoms. Common symptoms of a cracked tooth include pain when releasing the pressure from a clenched jaw, shooting pains when exposed to hot/cold food, and localised swelling. Where these symptoms are reported, the dentist will undertake further investigation.
  • The dentist will inspect the surface of the tooth and the surrounding gums – Where no obvious crack in the tooth is visible (even under a magnifying glass), the dentist may use a dental dye and handheld exploratory instruments to attempt to highlight and feel any change in the integrity of the tooth’s surface that could indicate a crack. The gums will also be inspected for any swelling or discolouration.
  • The dentist will take an x-ray of the mouth  – In the case of cracked teeth, x-rays do not always produce a reliable means of determining whether any damage is present. This is because fractures in the teeth can be fine and therefore difficult to detect. However, the x-ray may reveal other indicators of a cracked tooth, such as any linked damage to the pulp in the centre of the tooth.

What does cracked tooth pain feel like?

Typically, a cracked or broken tooth will be visually evident – the patient will notice either a substantial crack in the tooth enamel or a significant portion of the crown will be missing. However, not all cracks in the teeth will be visually evident. Learning to recognise the symptoms of pain associated with a cracked or broken tooth can help to avoid more severe symptoms. 

Early signs of a cracked tooth are the most important. Typical symptoms described by patients include occasional pain when biting hard foods in an area – this pain is not normally easy to reproduce as the tooth only hurts when the exact angle of the crack is loaded. Diagnoses and potential intervention at this stage is key to avoiding the crack further compromising the tooth.

Types of cracked tooth pain include: 

  • Tenderness in the tooth/gum
  • Sensitivity and pain in response to temperature changes
  • Swollen and painful soft tissues surrounding the affected tooth
  • Pain and throbbing in the tooth/gum – the pain may worsen when lying down
  • Pain that radiates from the affected tooth to the neck, same-side-ear, lips, face, and jaw

Left unchecked, patients may also notice symptoms of bad breath and difficulty in opening the jaws. This is likely caused by an abscess resulting from the proliferation of harmful bacteria in the cracked tooth. From this point, further complications may include a fever and difficulty swallowing – always make a dental appointment regarding suspected cracked/broken teeth. 

How can I prevent my teeth from cracking?

Depending on lifestyle choices (e.g. participating in contact sports, rock climbing, sailing, etc.) or depending on potentially hazardous working environments (e.g. construction or work involving tools), the likelihood of cracked teeth may may be significantly higher or lower from person to person. However, there are ways to reduce the potential for encountering a cracked tooth….

  • Wear a mouthguard where applicable (e.g. during sports)
  • Refrain from biting into hard foods such as boiled confectionary or popcorn kernels  
  • Ask the dentist for advice on an overnight mouthguard to prevent grinding during sleep
  • For large old fillings and obvious signs of failure or cracks, consider covering the biting surface of the tooth with a hard material to support the tooth structure and prevent bending and flexing of the tooth structure under loading.

Cracked tooth treatment options

Depending on the type and severity of a cracked or broken tooth, the dentist may choose from a range of restorative treatment options. What is important to remember is that an incomplete fracture (i.e. partial fracture penetrating into the tooth with no loss of enamel) risks becoming a complete fracture if not treated – which could lead to greater infection issues and tooth loss. Below is summary of the different levels of damage that can occur….

  • Minor Damage (‘bonding’ is used to fill the crack or fracture) – Bonding is used to restore minor cracks or chips in the teeth. A composite resin is used to ‘fill in’ any cracks. The resin can also be shaped to give a natural/convincing finish. 
  • Medium Damage  (the tooth will be covered with a crown or onlay) – Where a cracked or broken tooth cannot be restored with bonding, a thin porcelain veneer may be attached to what remains of the enamel. A porcelain veneer gives a natural appearance and unifies the biting surface – like a roof on a house – to add strength the weakened structure.
  • Major Damage  (prosthetic crowns are used to restore the tooth) – Where little of the crown remains, restorative work will likely involve fitting a crown on top of the healthy root. This will involve shaping what is left of the tooth enamel to house the crown. Where nerve damage or significant infection to the root has occurred, root canal treatment to remove any infected material may also be required.

Treating a cracked or broken tooth does not guarantee that the tooth will not develop further issues linked to the original fracture. However, treatment can prolong the life of the tooth for many years (potentially for the lifetime of the patient). Treatment and regular checkups will also mean avoiding symptoms such as bad breath, swelling/tenderness in the gums, and jaw pain.  


Can a cracked tooth cause infection? – Yes. A cracked tooth can result in a grooved or pitted tooth surface that is hard-to-clean, providing the ideal breeding grounds for bacteria (the warm and wet interior of the mouth also contribute favourable conditions for bacteria). Where the bacteria proliferates, the infection can spread deep into the tooth, eventually affecting the root, gum, and surrounding tissues. If left untreated, a pus-filled abscess may form at the tip of the tooth root (periapical abscess) or in the gum tissue surrounding the root (periodontal abscess). The abscess can weaken the soft and supporting tissues, threatening the integrity of the tooth, gum, and jaw bone. In extreme unchecked cases, the infection can enter the bloodstream (requiring urgent medical attention). 

Can a cracked tooth cause jaw pain? – Cracked or broken teeth may cause pain in the jaw in different ways. First, where the cracked or broken tooth leads to infection, the resulting build up of harmful bacteria may cause painful swelling in the gum and jaw. Patients also report pain in the jaw where the fractured tooth causes nerve damage (this is especially noticeable when releasing bite pressure).

Can a cracked tooth cause ear pain? – Facial stimuli are transmitted to the brain via the two large trigeminal nerves – each nerve enters the face from near to the ear, meaning that any infection leading to pain and swelling may be felt in the jaw, lips, cheeks, cheekbones, brow, and ears. 

Does a cracked tooth show on x-ray? Not always. Cracks in the teeth may be so fine as to be indistinguishable on x-ray from the appearance of a whole tooth. However, the x-ray is able to highlight any potential issues with the pulp in the centre of the tooth, meaning that the dentist is able to use results from an x-ray to infer hidden issues such as cracked teeth. 

Can a cracked tooth cause headaches? – Yes. The two trigeminal nerves are the largest cranial nerves, entering the face close to the ear and serving the jaw, lips, cheeks etc. Any issues with the teeth can trigger problems such as headaches and migraines – a condition that is exacerbated by biting and chewing. Infection and acute pulpal symptoms can imitate nerve like pain.

Can a cracked tooth cause bad breath? Temporary bad breath may be linked to a malodorous diet (e.g. garlic, onions). However, persistent bad breath is linked to a proliferation of bacteria. A cracked tooth provides the ideal hard-to-clean environment in which bacteria can thrive – the bristles of the toothbrush may be too wide to get into the crack and give a thorough clean. 

Can a cracked tooth repair itself? Unlike other parts of the body capable of producing new cells (such as bone and skin), teeth do not have the ability to produce new enamel so cannot repair themselves. Cracked enamel must be treated by the dentist to ensure that further degradation of the tooth is minimised – in severe cases, cracked teeth cannot be restored and must be removed. 

What are the symptoms of an abscess? – Because an abscess forms either directly under the tooth root or to the side of the tooth root within the gum (i.e. under the gumline), there may not be obvious visual symptoms. 

Symptoms of an abscess include:

  • A persistent toothache 
  • Increased sensitivity to hot/cold
  • Pain or sensitivity when biting or chewing 
  • Swelling in the gum and surrounding tissues 
  • Swelling in the surrounding lymph nodes (i.e. swelling under the jaw) 

Symptoms of a tooth infection spreading to the body include:

  • Increased heart rate and faster breathing 
  • A feeling of uneasiness with a temperature/fever and headaches 
  • Dehydration – which manifests as dark urine with reduced frequency (diarrhea, vomiting, and stomach pains are also linked symptoms of an infection spreading to the body)

Patients suffering from an abscess linked to an infection from a cracked or broken tooth are advised to visit the dentist as soon as possible. 

Published On: April 22nd, 2016 / Categories: Dental Pain /

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