1. Faculty of Dentistry; University of Medical Science; La Habana Cuba
2. Center for Dental Medicine; University of Zurich; Zurich Switzerland
3. University of Bern; Bern Switzerland
4. ARDEC; Ariminum Odontologica; Rimini Italy
5. UNESP - Faculdade de Odontologia de Araçatuba; UNESP - Universidade Estadual Paulista; São Paulo Brasil