1. Department of Operative Dentistry, Endodontics, and Dental Materials; Bauru School of Dentistry; University of São Paulo; Bauru SP Brazil
2. Department of Endodontics; Pontifical Catholic University of Paraná; Curitiba PR Brazil
3. Department of Physics; Faculty of Philosophy, Science and Literature of Ribeirão Preto; University of São Paulo; Ribeirão Preto SP Brazil
4. Department of Physical Chemistry; Institute of Chemistry; São Paulo State University; Araraquara SP Brazil
5. Department of Endodontics; School of Dentistry; University of Texas Health Science Center at Houston; Houston TX USA
6. Department of Diagnostic and Biomedical Sciences; School of Dentistry; University of Texas Health Science Center at Houston; Houston TX USA