Paro-endo lesions
A paro-endo lesion is a form of periodontal disease in which pathogens pass from the endodont to the periodontium or vice versa.
There are 3 forms:
- Lesions of primarily endodontal origin
- Lesions of primarily periodontal origin
- Lesions with a combined endodontal and periodontal origin
Anatomical and pathological causes
There are various direct connections between the endodontium (tooth pulp) and the periodontium (tooth holding apparatus). On the one hand, the network of nerves and blood vessels enters the bone at the apex (root tip) from the tooth. In addition, about a third of all permanent teeth have additional lateral canals that leave the pulp laterally in front of the apex. In the case of teeth with multiple roots, there are often accessory canals in the area of the forked roots ( furcation ), which connect the crown pulp directly with the periodontium. Theoretically, microorganisms can also move between the periodontium and endodontium via all of these connection paths. The direction and speed of bacterial spread depends on the origin of the infection and the initial state of the tissues involved. On the one hand, bacteria that have infected the pulp cavity through deep caries can over time reach the surrounding periodontium along these connecting channels and also inflame it. Conversely, there is also the possibility that the microorganisms first colonize the periodontium and then ignite the endodontium via the numerous channels, although this course of inflammation is less common.
Primary endodontic lesions
The primary endodontic lesions originate from deep carious lesions. Once the bacteria have reached the pulp cavity, they can fully spread within a few days. If the pulpitis is not treated early enough, the microorganisms can reach and colonize the periodontium via the apex, but also via other side canals. Depending on the location, this inflammation shows up on the X-ray as apical periodontitis , if it is at the tip of the root, or lateral periodontitis, which is at a lateral canal outlet. If further treatment is neglected, the inflammation can spread in the bone and eventually penetrate along the surface of the root into the sulcus.
The treatment of primarily endodontic lesions lies in a professional root canal treatment . Here is a curettage initially contraindicated because here the periodontal fibers are removed. If there are bone defects in very pronounced lesions after the end of the root canal treatment, a curettage should only be carried out after a considerable period of time, as the damaged periodontium can usually regenerate itself. Thus, primarily endodontic lesions have the best chance of complete healing.
Primary periodontal lesions
The primary periodontal lesions, which originate in pronounced periodontal pockets, are to be assessed as less favorable. If left untreated, the bone defects can extend to the tip of the root and infect the pulp cavity retrograde (from the tip of the root). In this case, there are no carious lesions from which pulpitis started. Although the actual colonization of the tooth pulp in this way is controversial in the literature, such a deep lesion represents an impairment to the vitality of the tooth at the latest during therapy. With a thorough curettage in this area, damage to the tooth pulp cannot be excluded.
The therapy of a primarily periodontal lesion on a tooth that shows the clinical signs of a still vital tooth pulp is therefore initially a curettage, which is carried out closed or open depending on the location. Endodontic therapy follows when the bone lesion extends to the apex. If necessary, an apicectomy may also be necessary. Here, however, the prognosis for the tooth is already limited.
Combined periodontal and endodontal lesions
We speak of combined lesions when both periodontal and endodontal inflammation have developed independently of one another on the same tooth root. If these are not treated, they can spread over time to such an extent that the events overlap. In addition, the term combined lesions is often used when the actual origin can no longer be traced at the time of diagnosis.
The therapy of combined perio-endo lesions is similar to that of lesions of periodontal origin, but the root canal treatment must always be included. However, the prognosis for teeth with such pronounced inflammation is always to be viewed as very questionable. Therefore, in many cases only extraction or root amputation can lead to healing. In the case of lesions of unclear origin, root canal treatment should be carried out first and, if necessary, a curettage should be performed at a sufficient interval. Here, too, the fundamental decision remains whether a tooth is worth preserving at all or whether it should not be better extracted from the outset if the prognosis is poor.
Root amputation
In the permanent set of teeth, the molars of the upper and lower jaw and the first premolar of the upper jaw have more than one root. If only one of these roots is not worth preserving due to a fraction or a paro-endo lesion, there is sometimes the chance to only remove this. For this, the root must be easily accessible and the remaining tooth must have a good prognosis. In order to be able to perform a root amputation, a successful root canal treatment must first take place. The relevant root can then be separated and removed in an oral surgical operation. The remaining tooth is then closed with a filling in the area of the amputation wound. B. be supplied with a prosthetic crown. This type of treatment was established during the time when implants were not yet an equivalent alternative. Since a private additional payment from the patient is necessary for this elective procedure, both options must now be weighed against each other.
