Supplementary Material for: The in vivo Inhibition of Oral Biofilm Accumulation and Streptococcus mutans by Ceramic Water

Combustion-synthesized titanium carbide ceramics uniformly disperse silver, producing silver ions and hydroxyl radicals in water. This generates antimicrobial activity against various bacteria. One such bacterium is <i>Streptococcus mutans</i>, a gram-positive anaerobic bacterium known as a major pathogen of dental caries. In this study, we analyzed the inhibition of oral biofilms and <i>S. mutans</i> by ceramic water in in vitro and human studies. <i>S. mutans</i> strains showed significantly lower antimicrobial and sucrose-dependent adhesion activity in the presence of ceramic powder compared with untreated culture medium. Confocal microscopy revealed that <i>S. mutans</i> biofilm structures with ceramic powder were thin and coarse. Twenty-seven volunteers (13 males, 14 females; 18-37 years old, mean 25.2 years) were enrolled for subsequent studies. After each meal, one group was asked to rinse with ceramic water while the other rinsed with untreated water for 1 week. After 1 week, the rinsing contents were switched between the groups and the same protocol was followed for an additional week. After rinsing with ceramic water, the average plaque score was 43.0 ± 3.7, which was significantly lower than the baseline value (74.1 ± 5.7, <i>p </i>&lt; 0.001). However, no significant difference was observed when rinsing with untreated water. In addition, the total number of <i>S. mutans</i> in saliva was significantly reduced after rinsing with ceramic water compared with untreated water (<i>p </i>&lt; 0.05). These results suggest that ceramic water possesses antimicrobial activity against <i>S. mutans</i> and inhibits biofilm formation. Rinsing with ceramic water can also inhibit dental plaque formation and <i>S. mutans</i> colonization in humans.