Questions and Answers

When is a root canal treatment necessary?

It is necessary if the dental nerve is infected. This can have various reasons. A chemical or physical trauma (e.g. when teeth are ground), a crack in the tooth (e.g. by crunching or because of a fall) or caries and leaky restorative margins and crown margins can result in the entry of bacteria or their toxins in the dental nerve. In addition, deep fillings or crowns that are very close to the dental nerve may make a root canal treatment necessary. If there is no treatment, the pulpitis results in an uncontrollable dying of the nerve and the inflammation can spread to the periodontium surrounding the root (apical ostitis). This will be visible on the X-ray image as a dark spot at the root tip (apical radiolucency).

The signs of inflammation of a sick dental nerve vary from continued sensitivities to heat and cold, spontaneous pain (in particular at night), pain when biting, knock sensitivity to throbbing pain and swelling of the surrounding soft tissue. Sometimes a headache or jaw pain may be an indication that a root canal treatment is necessary. It is not uncommon that there is no pain at all and it can merely be seen in the X-ray image that there is an inflammation in the bone which comes from the tooth (apical ostitis).


In case of chronic forms, the infection does not involve any pain. It is not uncommon that the effects of the infection are only discovered on a radiograph in the form of a dark spot at the root tip (apical ostitis). The bone around the dental root has dissolved. This degradation is progressive and may lead to an acute inflammation with pain, swelling and purulence.

Sometimes it is no longer possible to safe the tooth by means of a root canal treatment due to the tooth’s degree of damage or due to a root fracture. Even if you do not feel any pain at that time, the tooth should be pulled because if the affected tooth remains in the oral cavity, the infection may worsen, it may result in a painful purulent abscess in the bone or it can spread into other regions of the body via the blood. After the removal of the tooth, there are different possibilities to close this gap (implant, bridge).

If in case of a root canal treatment bacteria have remained in the canal system or if they have formed again after the treatment, this may result in a new inflammation. Possible causes are: 

  • canals have been overlooked or have not been treated at an adequate length or width,
  • the cleaning effect has been too low because of a complex canal anatomy,
  • bacteria entered the root canal system again via caries, leaky fillings or because the crown was implanted too late.

In case of such a diagnosis, the old root canal filling is completely removed and the complete canal system, including any canals that may have been overlooked, is thoroughly cleaned. Afterwards, filling and closure are made in the same way as during a first treatment.

You can only treat the parts you see. Usually, teeth have more root canals than are visible to the naked eye. A lower front tooth, for example, principally has one canal; in case of 40% of the patients, however, a second canal was detected under the microscope which could also be repaired. If inflammatory tissue remains in these ignored canals, the prognosis for the tooth is not good. Furthermore, each root is different and formed absolutely individually (C-shaped, oval, L-shaped, with bulges or ramifications). In order to be able to clean them absolutely thoroughly, the treatment by means of conventional methods is not sufficient. In addition to a high-performance microscope, a time-dependent individual irrigation protocol (disinfecting irrigation of the canals) is absolutely essential. The individuality of root canals must also be taken into account with respect to the root canal filling. That is why specialists worldwide prefer the filling with warm gutta-percha. By heating the gutta-percha within the root canal, the filling material becomes soft and can be closely adjusted to the individual form of the root canal by means of microscopic control.

The treatment usually takes one and a half to two hours and is in most cases completed within one session. Sometimes, additional appointments are necessary, especially in complex cases or if the inflammation is more serious.


Unfortunately, it is not possible to save every tooth by means of a root canal treatment. This is for example the case in the event of a root fracture or if the degree of damage is too high for a successful repair of the tooth. It is not always possible before the treatment to say for sure whether a tooth can be saved. Sometimes it is only possible to make a decision in this regard after a thorough inspection of the inner tooth.


Radiographs are usually taken before the treatment and at the completion of the treatment. In some cases, for example if the course of the canal is irregular, further radiographs from different angles are necessary.

Dental dam is a small sheet made of rubber that is fixed to the respective tooth with a clip to keep the bacteria in the saliva away from the treatment area during the whole treatment.

No, a local anesthesia ensures that you will not feel anything. In rare cases it can happen that a tooth is particularly sensitive. However, due to the possibilities we have today, here, a treatment free of pain is also usually the case.

After each invasive procedure, a regeneration phase is to be expected. During the natural healing process of your body, you may experience minor or moderate pain. The tissue and bones surrounding the tooth and a ligament that covers the dental root are, in most cases, inflamed before the treatment. This inflammation and the manipulation of the tissue during the treatment are the reasons for postoperative pain. As you keep your mouth open for a longer period of time during the treatment, your jaw, neck and back musculature may be slightly tense during the first days after the treatment. It can also be the case that the gums are slightly irritated for a short period of time because of the fixing of the sheet made of rubber (dental dam). The symptoms are of short duration and can usually be completely alleviated by means of painkillers, such as ibuprofen or paracetamol. We recommend taking one pill for pain therapy within the first hour after the treatment so that the effect occurs before anesthesia has worn off. A postoperative inflammation (phoenix abscess) with severe pain, swelling and fever is extremely rare. Here, the taking of antibiotics as an accompanying measure is indicated. Please contact our clinic if you should suffer such pain. After the root filling, your tooth will in general feel different than the surrounding teeth for a while.

A root canal treatment involves the following risks:

These include in particular:

  • mild to severe pain shortly after the root canal treatment for several hours to days
  • incomplete root canals not continuing to the end of the root tip
  • incomplete effect of anesthesia
  • perforation of the root or pulp floor
  • swellings or abscesses shortly after the root canal treatment or later
  • breaking off of root canal instruments in the root canal
  • injury of the tissue at the root tip
  • overfilling of root canals (leakage of filling material from the roof tip)
  • stain or darkening of a tooth with root filling
  • chipping, breaking off, comminution of teeth with root fillings
  • continuity or  recurrence of discomfort, pain or inflammation

Any complications may mean that you have to take antibiotics or that further treatments, such as an apicoectomy, are necessary or even that the tooth will be lost.

The treatment by a specialist in our clinic is carried out with the highest precision under the surgical microscope, according to the latest scientific knowledge and by means of the latest technology. Thus, we achieve success rates of up to 96%.

The chances of success, however, depend on the condition of the tooth before the treatment and on the type of aftercare. If a tooth is merely inflamed and the surrounding periodontium and bones are healthy, success rates amount to 96%. If the inflammation has already spread and led to a dissolution of the bone (ostitis apicalis) or if the tooth is not sufficiently restored after a successful treatment (partial crown, crown), chances of success decrease significantly.

As with all medical interventions regarding the human body, we cannot guarantee an absolute success. If there is no improvement, further treatment steps, such as an apicoectomy or the removal of the tooth, may be necessary.

In order to avoid an injury of the soft tissue, such as cheek, tongue or lip, please refrain from hot beverages and any food intake until anesthesia has completely worn off.

Without a restoration of the cusps, root-treated teeth may easily fracture. Therefore, please avoid any weight bearing of your tooth until such a provision has been included.

Do not change your daily oral hygiene measures. 

In case the cavity of your tooth has been closed with a temporary filling, it is not unusual that a thin layer wears off between the treatment dates. If you feel that the complete filling got lost, please contact our clinic.

The completed root canal filling is only the first step to restore the functioning of your tooth. In order to ensure a long-term success, the tooth must be provided with a suitable fixed restoration. In most cases this is a provision including the cusps (overlay, partial crown, crown) that restores the full chewing force of the weakened tooth and protects it from fractures. With a good oral hygiene, the use of dental floss, regular visits to the dentist and professional dental cleaning, a sufficient restored tooth with root-filling has the same lifespan as a natural tooth. In most cases, radiographs of the tooth concerned are taken at intervals of 3, 6 and 12 months and afterwards every year up to four years after the treatment in order to monitor the healing process. In rare cases, an inflammation of the tooth does not heal even after months or the tooth continues to cause problems or even causes problems after years without any discomfort. Often, the tooth can be saved by means of a renewed root canal filling, a so-called revision.

In most cases, radiographs of the tooth concerned are taken at intervals of 3, 6 and 12 months and afterwards every year up to four years after the treatment in order to monitor the healing process.

The treatments are very complex and extend over several hours. In order to achieve an optimum treatment success, we take the necessary time. Therefore, billing for patients with statutory insurance coverage also has to be done in accordance with the German Scale of Fees for Dentists (Gebührenordnung für Zahnärzte, GOZ). However, depending on the level of difficulty, patients with private health insurance may also incur costs which are not borne by the private insurance companies.

During the initial examination, all measures and the individual course of treatment are discussed. For many patients this is extremely helpful to allay their fears and concerns. If you still prefer a treatment under sedation or general anesthetic, we are prepared.

In extremely rare cases there can be a repeated inflammatory reaction regarding the root tip that requires a small surgical procedure. During such a treatment, the inflamed root tip is removed under anesthesia and free of pain. Afterwards, the root canal concerned is cleaned from the tip onwards and filled in such a way that bacteria cannot enter. The missing bone substance regenerates. The chances of success with respect to an apicoectomy are 50%.

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