1. Institute of Dentistry, University of Turku, Turku, Finland
2. Department of Infectious Disease Surveillance and Control, National Institute for Health and Welfare (THL), Helsinki, Finland
3. Institute of Dentistry, University of Helsinki, and Department of Oral and Maxillofacial Surgery, Helsinki University Central Hospital, Helsinki, Finland
4. Unit of Living Conditions, Health and Wellbeing, and Department of Environmental Health in Environmental Epidemiology Unit, National Institute for Health and Welfare (THL), Kuopio, Finland
5. Unit for Specialized Oral Care in the Metropolitan Area and Kirkkonummi, Helsinki, Finland