Periapical lesions regularly occur in untreated teeth, as well as in teeth that have already been subjected to endodontic treatment. There are various known factors that lead to effective endodontic treatment where the clinical symptoms disappear and the periapical lesion disappears or decreases in size. The risk of painful inflammation alongside a persistent periapical lesion is small, even if the periapical lesion has increased in size. The survival of a tooth with a periapical lesion that has undergone root canal treatment is 87% after 10 years. In cases where an endodontically treated tooth has to be extracted, a restorative problem is often the reason for extraction, while a persistent periapical lesion has a limited effect on tooth loss. There are insufficient data available on the effect of a periapical lesion on general health. Schlagwörter: effectiveness, general health, pain, periapical lesion, survival