1. Department of Physiological Science, Piracicaba Dental School, University of Campinas (UNICAMP), Av Limeira, 901, Piracicaba, São Paulo 13414-903, Brazil
2. Department of Restorative Dentistry, University of Illinois at Chicago, College of Dentistry, 801 S. Paulina, Chicago, Illinois 60612
3. Department of Biomedical Sciences, University of Illinois, College of Medicine at Rockford, 1601 Parkview Avenue, Rockford, Illinois 61107
4. Institute of Physics Gleb Wataghin, University of Campinas (UNICAMP), Cidade Universitária Zeferino Vaz, Barão Geraldo, Campinas, São Paulo 13083-859, Brazil