1. University of Medicine; School of Dentistry; Milan Italy
2. ARDEC, Ariminum Odontologica; Rimini Italy
3. POI, Programa Odontológico Internacional; Cartagena de Indias Colombia
4. Faculty of Dentistry; São Paulo University; USP Ribeirão Preto Brazil
5. Faculty of Dentistry; University of Medical Science; La Habana Cuba