Anti-biofilm effect of dental adhesive with cationic monomer.

The incorporation of polymerizable cationic monomers has been attempted to generate dental resinous materials with antibacterial activity. This study tested the hypothesis that a dental adhesive containing a cationic monomer, methacryloxylethyl cetyl dimethyl ammonium chloride (DMAE-CB), would influence biofilm formation and gtf gene expression of Streptococcus mutans. The effect of the photo-polymerized DMAE-CB-incorporated adhesive on in vitro biofilm accumulation was investigated with spectrophotometry and scanning electron microscopy. The relative level of gtf gene expression by Streptococcus mutans in the biofilm was quantified by real-time reverse-transcription polymerase chain-reaction. The DMAE-CB-incorporated adhesive significantly decreased bio-film accumulation on its surface (P < 0.05), and suppressed the expression of gtfB and gtfC of Streptococcus mutans in the biofilm (P < 0.05). The results suggest that the cured DMAE-CB-incorporated adhesive may hamper biofilm accumulation via selective down-regulation of the expression of gtf genes in Streptococcus mutans.