1. Department of Community Dentistry; Division of Health Education and Health Promotion; Piracicaba Dental School; University of Campinas - UNICAMP; Piracicaba SP Brazil
2. Department of Community Dentistry; Division of Public Health Dentistry; Piracicaba Dental School; University of Campinas-UNICAMP; Piracicaba SP Brazil
3. Department of Mathematics; Statistics and Chemistry; Luiz de Queiroz College of Agriculture; University of São Paulo; Piracicaba SP Brazil