Colony forming unit (CFU) cell viability counts and XTT cell metabolism assays of microorganisms grown on orthodontic acrylic resin disks from the control (0 wt.% QAMS) and four experimental groups (0.4–6 wt.% QAMS). (A, D) S. mutans biofilms. (B, E) A. naeslundii biofilms. (C, F) C. albicans. For each parameter (upper case letters for baseline and lower case letters for 3 months), groups with the same letters are not statistically significant (p > 0.05; note – only groups that are not significantly different are labeled). For comparisons between baseline and 3 months, groups connected with a bar are not statistically significant (p > 0.05).