1. School of Dentistry; University Center of Maranhão-UniCeuma; São Luís Brazil
2. Department of Restorative Dentistry; School of Dentistry; University of São Paulo; São Paulo Brazil
3. Department of Oral Biological and Medical Sciences; Faculty of Dentistry; The University of British Columbia; Vancouver BC Canada
4. Center of Materials Science and Technology; Energy and Nuclear Research Institute; São Paulo Brazil