1. Department of Oral Health, Faculty of Oral Health Science, Kristianstad University, Kristianstad, Sweden
2. Department of Cariology, Institute of Odontology, Sahlgrenska Academy, Gothenburg, Sweden
3. Department of Periodontology, Faculty of Odontology, Malmö University, Malmö, Sweden
4. Department of Periodontology, Blekinge Hospital, Karlskrona, Sweden