Before patricipating patients go to preop, the investigators have them take a mouth rinsing quick-test, periosafe(c), that tells specifically about periodontitis. Participants go to surgery (upper gi) and have a normal operation following our clinics standards and normal follow up. After the investigators analyze the patient data concerning possible complications and do they have relations between the positive periodontitis results. Participants are also given advice about seeing a dentist if positive results are seen, but the operating surgeons do not get to know the mouth rinsing test results.