[1] Univ Fed Rio Grande do Sul, Porto Alegre, RS, Brazil
[2] Univ Fed Pelotas, Dept Periodontol, Pelotas, Brazil
[3] Hosp Clin Porto Alegre, Expt Res Ctr, Porto Alegre, RS, Brazil
[4] Univ Fed Rio Grande do Sul, Dept Periodontol, Porto Alegre, RS, Brazil