1. Dentistry School Basic Research Center Universidade Federal do Rio Grande do Sul Porto Alegre Brazil
2. Laboratory of Technological Processes and Catalysis Institute of Chemistry Universidade Federal do Rio Grande do Sul Porto Alegre Brazil
3. School of Chemistry Molecular Science Institute University of Witswatersrand Johannesburg South Africa
4. Department of Chemical Sciences University of Johannesburg Johannesburg South Africa
5. Department of Morphological Sciences Institute of Basic Health Sciences Universidade Federal do Rio Grande do Sul Porto Alegre Brazil