What is sterile necrosis?

Sterile pulp necrosis describes the loss of tooth vitality without bacterial influence. This can occur as a result of trauma, for example an accident combined with a fall or a blow on a tooth. Trauma from childhood can also result in pulp necrosis decades later.

Sterile necrosis can remain symptom-free and cause no symptoms for years. Often the sterile form is a chance finding, resulting from a cold test or an X-ray. The result of the diagnosis is a root canal treatment, which is initiated when there are complaints.

What is infected pulp necrosis?

Infected pulp necrosis is caused by bacterial influence and also deprives the tooth of its vitality. The big difference here is that the bacteria, which are usually caused by a spreading caries, decompose and metabolize the vessels within the tooth pulp, which leads to discomfort. The unpleasant pain is caused by the fact that in the metabolic processes of the bacteria gases are formed as decomposition products, which cannot escape because the pulp is closed.

There is an increase in pressure inside the tooth, which the longer and more intensively the bacteria can metabolize, the stronger and more unpleasant it can become. The complaints can only be alleviated by a root canal treatment, in which the canal system of the tooth is completely cleaned and disinfected so that all bacteria are removed. If the infected pulp necrosis is not treated, the bacteria will spread beyond the tip of the root and can form a gangrene. Due to the body’s defensive reaction, which however does not manage to eliminate the bacteria in the canal system, an inflammation under the root tip, a so-called apical granuloma, develops.

Diagnosis

Diagnostically, a tooth affected by pulp necrosis is transferred by clinical tests. These primarily include the vitality test, in which a cold test is performed. A healthy tooth feels the cold and reacts by feeling it for a short time, which disappears after one or two seconds.A tooth with pulp necrosis does not feel the cold because the nerve vessels in the pulp are dead and therefore do not feel anything.

Furthermore, advanced pulp necrosis can lead to an apical granuloma, which is also conspicuous in a knock test. The percussion is painful when tapping the tooth with a blunt object. This pain can be explained because the tooth is pressed into inflammatory tissue.

However, in the case of pulp necrosis, which is not yet so far advanced, the percussion test may be inconspicuous. In the case of an apical granuloma, an X-ray may also show a brightening of the affected area caused by bone resorption by the inflammatory tissue. When reaming the tooth, the dentist can also recognize by a decaying smell and the color of the nerve tissue that the nerve has already been decomposed.