1. Post Graduate Program in Dental Sciences; Federal University of Santa Maria, Brazil; Rua Marechal Floriano Peixoto, 1184 Santa Maria RS 97015-270 Brazil
2. Post Graduate Program in Dental Sciences; Federal University of Rio Grande do Sul; Rua Ramiro Barcelos, 2492 Porto Alegre RS 90035-003 Brazil
3. Department of Restorative Dentistry; Federal University of Santa Maria, Brazil; Rua Marechal Floriano Peixoto, 1184 Santa Maria RS 97015-270 Brazil
4. Department of Stomatology; Federal University of Santa Maria, Brazil; Rua Marechal Floriano Peixoto, 1184 Santa Maria RS 97015-270 Brazil