1. Federal University of Rio Grande do Sul; Center for Community Oral Health Research; Rua Ramiro Barcelos 2492 Porto Alegre Rio Grande do Sul Brazil 90035-003
2. Federal University of Rio Grande do Sul; Department of Preventive and Social Dentistry; Porto Alegre Brazil
3. Post-graduation Program in Medical Sciences, Universidade Federal do Rio Grande do Sul; Social Medicine/Epidemiology; Jose de Alencar 1244, 1009 Menino Deus Porto Alegre Rio Grande do Sul Brazil 90880-480