What a vertical root fracture is
A vertical root fracture begins in the root of a tooth and runs lengthwise along it, towards the biting surface. The pieces often do not separate completely and stay in place, but a gap opens between them that bacteria can pass through. Because the fracture lies beneath the gum and bone, it cannot be seen by looking in the mouth. Inflammation travelling along the fracture line can, over time, destroy the bone beside the root.
Crack or fracture
In everyday speech the two words are used interchangeably; in dentistry, the American Association of Endodontists (AAE) separates them as follows. The boundary is not always sharp, and which one is present usually becomes clear only when the examination, measurements and imaging are considered together.
- Craze line: a fine crack confined to the enamel, with no loss of tooth structure.
- Cracked tooth: a crack of unknown depth that can run from the biting surface towards the root.
- Vertical root fracture: a root fracture whose pieces have not yet fully separated.
- Split root: a fracture whose pieces have separated completely along its length.
Who is more likely to get one
Vertical root fractures mostly occur in teeth that have had root canal treatment, and they rank high among the reasons such teeth are lost. According to the AAE, the risk is greatest in teeth with a post (a rod placed in the canal to hold the filling or crown above it) or where a lot of root structure was removed during treatment. Even so, they can also occur in teeth that were never treated, as a result of strong chewing and clenching forces repeated over the years. How to protect a root-filled tooth from breaking is covered in a separate article; this one deals with what happens once a fracture has formed.
Why the symptoms are vague
A vertical root fracture often causes few symptoms and can go unnoticed for a long time; the AAE notes that these fractures are usually discovered when the surrounding bone and gum become infected. A root-filled tooth has no nerve, so sharp toothache is not to be expected. The signs tend to come from around the tooth and can look like gum disease or a root canal treatment that has not healed:
- Pain or tenderness when biting or when the tooth is tapped
- Swelling that keeps coming back beside the same tooth
- A small spot on the gum, like a pimple, that drains from time to time (a sinus tract)
- A deep, narrow pocket at one point around the tooth while the gum is healthy elsewhere
- A loose tooth
Why diagnosis is difficult
A standard X-ray shows the tooth from one direction only; if the fracture line is not aligned with the beam, it does not show up. What is usually seen is not the fracture itself but a dark area of bone loss running down one side of the root, often shaped like the letter J. Cone beam computed tomography (CBCT) shows the tooth in three dimensions, but root fillings and metal posts create streak-like artefacts in the image. In a systematic review pooling studies on root-filled teeth, CBCT detected on average about seven in ten fractures, and artefact lines were sometimes mistaken for fractures.
That is why a firm diagnosis sometimes needs a direct look: the gum is lifted in a small surgical procedure and the root surface is examined under magnification. The AAE still regards this kind of inspection with a microscope as the most reliable method. At times the fracture is confirmed only after the tooth or root has been removed.
What the options are
A fractured root does not heal on its own, and repeating the root canal treatment does not seal the fracture line. In single-rooted teeth, meaning front teeth and most premolars, extraction is usually needed; the AAE states that no successful treatment has been developed for these teeth. In large molars with more than one root, if only one root is fractured, that root can in selected cases be removed and the rest of the tooth kept:
- Root amputation: the fractured root is cut away from the upper part of the tooth and removed.
- Hemisection: the tooth is divided in two, the fractured root is removed with its half, and the remaining half is restored with a crown.
These routes are suitable only if there is enough bone around the remaining roots, the gum is healthy and what is left of the tooth can be restored; the decision is often made with a specialist. Attempts to bond the fractured pieces together and put the tooth back in its socket have also been reported. However, a systematic review of these attempts found the evidence sparse and of low quality, with results ranging from complete failure to complete success.
What happens after extraction
The gap left by an extracted tooth does not always have to be filled, but if it stays open for long, neighbouring teeth can drift and the opposing tooth can over-erupt. Options such as an implant, a bridge or a removable denture are discussed according to the bone and the neighbouring teeth. If a fractured tooth stays in the mouth while inflammation continues, bone loss around it can increase and narrow the later options. For that reason, once the fracture is confirmed, it is generally better not to put the decision off for long.
Frequently asked questions
Will antibiotics cure a root fracture?
No. Antibiotics can hold back a spreading infection for a while and reduce swelling, but because the fracture line remains, the problem usually returns. Whether antibiotics are needed is for your dentist to decide; do not start treating yourself with old medicines left over at home.
My tooth has a post. Does that mean it will fracture?
No. A post is one of the factors that raise the risk, but most teeth with posts serve well for years. What matters is recognising the signs: if you notice recurring swelling, discharge or pain on biting next to the same tooth, do not put off a check-up.
What happens if I do not have the fractured tooth removed?
Some fractures stay quiet for a while, but as long as bacteria pass along the fracture line, inflammation and bone loss usually progress. Recurring swelling, a bad taste and bone loss extending towards the neighbouring tooth can follow. How long it is reasonable to wait is discussed on the basis of the examination and imaging.
Can a young, healthy person get a vertical root fracture?
Yes, though it is less common. In teeth that have never had root canal treatment, these fractures are mostly linked to strong forces repeated over the years, such as clenching or grinding at night. If you have such a habit, protection such as a night guard can be discussed at your examination.
How long does a tooth last after root amputation or hemisection?
Good results lasting many years have been reported for teeth kept with these procedures, but the outcome depends on the bone around the remaining roots, the health of the gum, how the tooth is restored and the biting forces. Cleaning between the remaining roots can be harder, so care with interdental brushes and regular check-ups become more important.
Is a CT scan always necessary?
No. The examination and standard X-rays come first; a CT scan is considered when they are not enough and when the result would change the treatment decision. A small-field scan covering only the area in question keeps the radiation dose low. Because a scan may not give a definite answer either, the dentist weighs all the findings together.
Sources
This article draws on AAE publications on cracked teeth and vertical root fractures and on two systematic reviews: one on how well CT scans detect these fractures, one on attempts to repair fractured roots. Evidence on repair attempts is sparse and of low quality.
- American Association of Endodontists — Cracked Teeth and Vertical Root Fractures: A New Look at a Growing Problem (Endodontics: Colleagues for Excellence, 2022 Edition)
- American Association of Endodontists — Cracked Teeth
- BMC Medical Imaging — Diagnostic efficacy of cone-beam computed tomography for detection of vertical root fractures in endodontically treated teeth: a systematic review
- Australian Endodontic Journal — The Efficacy of Surgical Techniques for the Management of Confirmed Vertical Root Fractures: A Systematic Review
This content is for general information only and does not replace an examination.
Edited by
Papatya Dental
This article draws on the clinical experience of the Papatya Dental team and is reviewed for accuracy before publication.
- Last updated:
- 2026-09-21
- Editorial contact:
- icerik@papatyadental.com