Molecular Evaluation of Antimicrobial Mouthwash Effects on Streptococcus mutans Isolated from Dental Plaque Antimicrobial Mouthwash Effects on Streptococcus mutans Isolated from Dental Plaque
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Abstract
Dental caries is strongly associated with Streptococcus mutans, which contributes to biofilm formation through virulence factors such as the gtfB gene encoding glucosyltransferase B. Chlorhexidine (CHX) mouthwash is widely used as an antimicrobial agent; however, its molecular effect on virulence gene expression remains insufficiently explored. This study intends to evaluate the in vivo effect of 0.12% chlorhexidine mouthwash on the expression of the gtfB gene in Streptococcus mutans. A prospective, self-controlled before-and-after paired study was conducted on 40 patients with active dental caries. Dental plaque samples were collected before (T0) and after (T1) a 14-day regimen of twice-daily chlorhexidine mouthwash use. Gene expression was assessed using RT-qPCR, with 16S rRNA as the housekeeping gene. The expression levels were calculated using the 2^−ΔΔCt method, and statistical analysis was performed using a paired t-test. A significant reduction in gtfB expression was observed following chlorhexidine use with an approximate 7-fold downregulation (fold change = 0.14). This reduction was highly significant (P < .0001). In conclusion, Chlorhexidine mouthwash significantly suppresses gtfB gene expression in S. mutans, indicating its ability to inhibit key virulence mechanisms involved in formation of biofilm and development of dental caries. These findings support its ability to use as an effective preventive strategy, particularly in high-risk patients.
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