1. Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Av Limeira, 901, Piracicaba, São Paulo 13414-903, Brazil
2. Laboratory of Technological Plasmas, Engineering College, Univ Estadual Paulista (UNESP), Av Três de Março, 511, Sorocaba, São Paulo 18087-180, Brazil
3. Institute of Physics Gleb Wataghin, University of Campinas (UNICAMP), Cidade Universitária Zeferino Vaz, Barão Geraldo, Campinas, São Paulo 13083-859, Brazil
4. Department of Restorative Dentistry, University of Illinois at Chicago, College of Dentistry, 801 S Paulina, Chicago, Illinois 60612
5. Department of Orthopedic Surgery, Rush University Medical Center, 1611 W Harrison, Chicago, Illinois 60612