FIG 4.

Treatment of in vitro saliva-plaque biofilms with Dual Zinc plus Arginine reduced the biofilm Young’s modulus. Saliva-plaque biofilms were grown for 5 days and treated with solutions of 1.5% arginine (Arg), 0.96% zinc (Zn), DZA, or PBS (untreated control) for 2 min. Treated biofilms were then analyzed using uniaxial mechanical indentation. (A) Biofilm thickness was determined from this analysis. Data are presented as a box and whisker plot. (B) The lower linear portion of stress-strain curves of saliva-plaque biofilms. Data presented as mean ± SD. (C) From this analysis, the Young’s modulus (stiffness) was also determined. Data are presented as a box and whisker plot. Four biological replicates each with three technical replicates. *, P < 0.05; ns, not significant. Statistical comparisons are to the untreated control.