1. Section for Periodontology, Department of Dentistry and Oral Health Aarhus University Aarhus Denmark
2. Department of Clinical Biochemistry Aarhus University Hospital Aarhus Denmark
3. Section of Periodontology and Preventive Medicine, Department of Dental Medicine Karolinska Institutet Stockholm Sweden
4. School of Dentistry, Facultad de Medicina Pontificia Universidad Católica de Chile Santiago Chile