A review article on the history of focal infection, published in this issue of LKS 5/2023 on pages 86-91, highlights the ambiguity and often precipitous twists and turns of the issue. A working group organized by the CSK and the professional societies of the CJP set out to determine whether there is a need to address this issue at all. And if the theory is indeed still relevant, how to carry out the examination and eventual therapy as efficiently as possible and yet as gently as possible for the patient. The key is the principle of "nihil nocere", which requires not to underestimate the possible risks, both systemic and dental. Translated with DeepL.com (free version)