Medical Encyclopaedia › Root canal treatment (short definition)
In brief: In root canal treatment (endodontics), inflamed or dead tissue is removed from the inside of a tooth, and the canal system is cleaned and sealed tightly. The aim is to preserve the tooth and to prevent inflammation in the jawbone or allow it to heal. With modern local anaesthesia, the procedure is usually no more unpleasant than a larger filling.
When is it needed?
Inside every tooth is the dental pulp with nerves and blood vessels. Deep caries, leaky fillings, cracks, accidents or repeated treatments can inflame it (pulpitis). Typical are severe, often throbbing pains that persist after cold or heat stimuli or occur at night. Other signs are pain on biting, swelling or a small pus fistula on the gum. If the tissue dies (pulp necrosis), bacteria can reach the bone via the root tip and cause inflammation there (apical periodontitis), up to an abscess or fistula. Sometimes this happens without symptoms and is only noticed on an X-ray.
Procedure
Beforehand, the response of the dental nerve is tested and an X-ray is taken; with complex root anatomy, a three-dimensional scan (CBCT) can occasionally be useful. Treatment is carried out under local anaesthesia and can take one or more sessions. Where possible, the tooth is isolated with a rubber dam so that no saliva enters the canals; it also prevents small instruments from being swallowed. After opening the tooth, the canals are located, their length is determined electronically and by X-ray, and they are widened with fine hand or rotary files. Irrigation solutions, usually sodium hypochlorite, dissolve tissue remnants and reduce bacteria. A medicinal dressing can be placed between sessions. Finally, the canals are sealed tightly with a rubber-like material (gutta-percha) and a sealer; a check X-ray shows the result. Magnifying loupes or a dental microscope make it easier to find fine canals.
After the treatment
For a few days, sensitivity on biting or mild pain may occur, which can usually be well controlled with common painkillers. Antibiotics are only necessary in exceptional cases in root canal treatment, for example in the case of spreading swelling or fever. Root-treated teeth are more brittle; back teeth in particular are therefore often protected with a partial crown or crown. A tight seal is important, as otherwise bacteria can re-enter the canals. Whether inflammation at the root tip heals is checked on an X-ray after a few months to about a year.
Success rates and risks
When carried out carefully, most root-treated teeth are preserved for many years. Less favourable are existing inflammation at the root tip, strongly curved or calcified canals, cracks in the root, re-treatments and a leaky restoration afterwards. Possible complications are a broken file fragment in the canal, perforation of the root, extrusion of material, vertical root fractures or persistent inflammation. If the inflammation does not heal, re-treatment (revision), apicoectomy or, as a last resort, extraction of the tooth may be considered. A root-treated tooth can darken slightly over time.
Alternatives and costs
The alternative is usually extraction of the tooth followed by closing the gap with a bridge, implant or denture. A preserved natural tooth is often the better solution, provided it can be restored sensibly in the long term. German statutory health insurers cover root canal treatment on front teeth, canines and premolars if the tooth can be preserved. For molars, under the treatment guideline of the Federal Joint Committee (G-BA), it is only a covered benefit under certain conditions, for example if it preserves a closed row of teeth, avoids a unilateral free-end gap or preserves existing dentures. Additional services such as rotary instrumentation or a microscope sometimes have to be paid for privately. A written cost estimate provides clarity. In difficult cases, referral to a practice specialising in endodontics can be useful. The best prevention is thorough oral hygiene, fluoride, regular check-ups and early treatment of caries.
Related terms in the encyclopaedia
Root canal treatment, Endodontics, Pulpitis, Pulp necrosis, Apical periodontitis, Dental abscess, Rubber dam, Gutta-percha, Apicoectomy, Dental crown, Caries, Sodium hypochlorite
Sources
- European Society of Endodontology (ESE): S3-Leitlinie zur Behandlung pulpaler und apikaler Erkrankungen (Duncan HF et al., Int Endod J 2023)
- European Society of Endodontology: Quality guidelines for endodontic treatment – consensus report. Int Endod J 2006
- Gemeinsamer Bundesausschuss (G-BA): Richtlinie für eine ausreichende, zweckmäßige und wirtschaftliche vertragszahnärztliche Versorgung (Behandlungsrichtlinie)
- Deutsche Gesellschaft für Zahn-, Mund- und Kieferheilkunde (DGZMK) / Deutsche Gesellschaft für Endodontologie und zahnärztliche Traumatologie (DGET): Patienteninformationen zur Wurzelkanalbehandlung
Note: This article is for general information and does not replace advice, diagnosis or treatment from a doctor, dentist or pharmacist. Last updated: October 2026.