Xylitol is a good Sugar substitute, get toothpaste made with this. Xylitol is a naturally occuring plant based fungal inhibitor. Xylitol gum (pref cinnamon) is great as it is anti fungal and will raise the PH of th mouth. Regular toothpaste may also be feeding the infection (via the sweetners etc).
Collodial silver spray/gargling has also helped others.