The aim of this course is learning the interactions between systemic diseases and periodontal diseases. At the end of the course, students will understand that the mouth is part of the body and that it can be affected by or involved in systemic pathological changes in the body. They learn that the effects of periodontal inflammation and/or infection as a focal source of infection are not limited to the oral cavity, but may be a risk marker for disease complications in many organs and systems. They know the bidirectional relationship between periodontal diseases and systemic diseases like diabetes mellitus, osteoporosis, etc.