Have you tried to eliminate the biofilm? Lactoferrin or lactoferrin with xylitol is a powerful tool. I have a post on this. Also just made a post about Kra Chai, apparently it has anti biofilm properties though I do not know how it would compare to the lactoferrin. Here is what they say about it:5.1. Inhibition of Biofilm Formation by Oral PathogensBiofilm formation on teeth surfaces is caused by multiple species of oral bacteria, the primary colonisers being mutant Streptococci . Biofilm formation is associated with several acute and chronic infections such as dental caries, gingivitis, and periodontitis and potentially contributes to antibiotic treatment failure againstStreptococcus pyogenes . In 2008, Limsuwan and Voravuthikunchai demonstrated that the extracts from B. rotunda, Eleutherine americana, and Rhodomyrtus tomentosa exhibited antibiofilm activity towards S. pyogenesat subinhibitory concentrations (1/32–1/2 MIC) for E. americana (7.81–125 μg/mL), R. tomentosa(0.24–7.81 μg/mL), and B. rotunda (1/2 MIC of 7.8 μg/mL). Antiquorum sensing test revealed that B. rotundashowed no inhibition activity, while R. tomentosa displayed strongest antiquorum effect followed by E. americana with moderate effect. However, microbial adhesion to hydrocarbon assay showed no changes in the cell-surface hydrophobicity of treated bacteria .The following year, Yanti et al.  reported the anti-biofilm property of B. rotunda extracted panduratin A, which was found to prevent and reduce the spread of multispecies oral bacteria in human mouth. The MIC of panduratin A was determined using the Clinical and Laboratory Standards Institute (CLSI) broth microdilution assay. Mucin-mixed panduratin A at concentrations between 0.5 and 40 μg/mL was coated on 96-well plates, followed by inoculation of three multispecies bacteria, Streptococcus mutans, Streptococcus sanguis, andActinomyces viscosus, and incubated overnight at 37°C to allow biofilm formation. Biofilm reduction effect was determined by further treating the bacteria with different concentrations of panduratin A (0.2–10 μg/mL) for up to 60 mins. Panduratin A exhibited bacteria reduction effect at MIC of 1 μg/mL and bactericidal effect against multispecies planktonic cells at 2X MIC, 8 hours after treatment. Reduction of biofilm formation was >50% at 8X MIC, whereas mass reduction of biofilm was observed within 15 mins at a concentration of 10 μg/mL . These results suggested that panduratin A can potentially be used to prevent colonisation of multispecies bacteria, under a dose-dependent manner, and that its effect is equal to commercially available synthetic drugs such as chlorhexidine gluconate .