1. School of Dentistry; Pontifical Catholic University of Rio Grande do Sul; Avenida Ipiranga; 6681; Partenon; Porto Alegre RS Brazil
2. Department of Biophysics; Federal University of São Paulo; Rua Pedro de Toledo, 669; São Paulo SP Brazil
3. Department of Oral Pathology; School of Dentistry; Universidade Federal de Pelotas (UFPel); Rua, Gonçalves Chaves, 457; Pelotas RS Brazil
4. Institute of Toxicology and Pharmacology; Pontifical Catholic University of Rio Grande do Sul; Avenida Ipiranga, 6681; Partenon; Porto Alegre RS Brazil