The effect of enzymatic treatment with mutanase, beta-glucanase and DNase on a saliva-derived biofilm model

Abstract

Introduction: The dental biofilm matrix is an important determinant of virulence for caries development and comprises a variety of extracellular polymeric substances that contribute to biofilm stability. Enzymes that break down matrix components may be a promising approach to caries control, and in light of the compositional complexity of the dental biofilm matrix, treatment with multiple enzymes may enhance the reduction of biofilm formation compared to single enzyme therapy. The present study investigated the effect of the three matrix-degrading enzymes mutanase, beta-glucanase and DNase, applied separately or in combinations, on biofilm prevention and removal in a saliva-derived in vitro-grown model. Methods: Biofilms were treated during growth to assess biofilm prevention or after 24 h of growth to assess biofilm removal by the enzymes. Biofilms were quantified by crystal violet staining and impedance-based real-time cell analysis, and the biofilm structure was visualized by confocal microscopy and staining of extracellular DNA (eDNA) and polysaccharides. Results: The in vitro model was dominated by Streptococcus spp., as determined by 16S rRNA gene amplicon sequencing. All tested enzymes and combinations had a significant effect on biofilm prevention, with reductions of >90% for mutanase and all combinations including mutanase. Combined application of DNase and beta-glucanase resulted in an additive effect (81.0%±1.3% SD vs. 36.9%±21.9% SD and 48.2%±14.9% SD). For biofilm removal, significant reductions of up to 73.2%±5.5% SD were achieved for combinations including mutanase, whereas treatment with DNase had no effect. Glucans, but not eDNA decreased in abundance upon treatment with all three enzymes. Conclusion: Multi-enzyme treatment is a promising approach to dental biofilm control that needs to be validated in more diverse biofilms.