1. Brazilian Cochrane Centre; Rua Pedro de Toledo, 598 Sao Paulo, SP Brazil 04039-001
2. State University of Heath Science; Department of Public Health; 113, Jorge de Lima Street Trapiche Maceió Alagoas Brazil 57010382
3. Universidade Federal de São Paulo / Escola Paulista de Medicina; Brazilian Cochrane Centre; Rua Pedro de Toledo 598 Vila Clementino São Paulo SP Brazil CEP 04039-001
4. State University of Maringá; Department of Periodontology; Av Mandacaru 1550 Maringá Brazil 87080-000