Evaluation of the Role of Smoking in the Peri-implantitis Pathogenesis

The cross-sectional study will be carried out in collaboration with the Departments of Periodontology in the Faculty of Dentistry at Bern University, Switzerland, Hatay Mustafa Kemal University, Dokuz Eylul University, Gazi University, and Ege University, Turkey. The first step of the study will be carried out in Turkey, and the second step in Switzerland. Since Hatay is one of the three provinces most affected by the 2023 earthquake in Turkey and Hatay Mustafa Kemal University Dental School was severely damaged, it is impossible to recruit samples from the patients in Hatay. Therefore, this project has been planned as a multicenter, and patient samples will be recruited from the Dokuz Eylül, Gazi University, and Ege University, Department of Periodontology, Faculty of Dentistry. The samples will be analyzed in the Laboratory of Oral Microbiology, Department of Periodontology, University of Bern, Switzerland. The study protocol was approved by the Ethics Committee for the Use of Human Subjects in Research of Dokuz Eylul University (Protocol No: 2023/GOA-8246).

This study will include 96 patients, equally divided into four groups:

• Smokers with peri-implantitis
• Non-smoker individuals with peri-implantitis
• Smokers with healthy peri-implant tissues
• Non-smoker individuals with healthy peri-implant tissues

Smoking status will be categorized into two groups: smoker and non-smoker (never smoker). The non-smoker group will include former smokers who stopped smoking at least 6 years ago.

The cigarettes smoked per day, smoking index (self-reported average cigarettes per day x years of tobacco use), and smoking pocket year will be calculated (self-reported average cigarettes per day x years of tobacco use / the number of cigarettes in a pocket). Smoking status will be detected according to self-report. Smoking status will be later validated by saliva cotinine levels. Salivary cotinine concentration for smoking will be accepted at 5-7 ng/ml. Smoking severity will be determined by higher concentrations.