1. Division of Periodontics; Department of Prosthodontics and Periodontics; Piracicaba Dental School; University of Campinas; Piracicaba São Paulo Brazil
2. Division of Histology; Department of Morphology; Piracicaba Dental School; University of Campinas; Piracicaba São Paulo Brazil
3. Division of Biostatistics; Department of Community Dentistry; Piracicaba Dental School; University of Campinas; Piracicaba São Paulo Brazil