1. Department of Dentistry; University of Alberta; Edmonton Canada
2. Departament of Restorative Dentistry; Federal University of Santa Maria; Brazil
3. Department of Prosthodontics; Paulista University; São Paulo Brazil
4. Department of Dentistry and Dental Hygiene; Clinical Dental Biomaterials, University of Groningen; Groningen The Netherlands
5. Department of Dental Materials and Prosthodontics; São Paulo State University; São José dos Campos São Paulo Brazil