1. Department of Dentistry; Ponta Grossa State University; Ponta Grossa Brazil
2. Assistant Professor, Department of Dental Materials and Prosthodontics, Araraquara Dental School; UNESP-Univ Estadual Paulista; Araraquara Brazil
3. Assistant Professor, Department of Dentistry; Ponta Grossa State University; Ponta Grossa Brazil