There are several good products out now that can help fight against getting cavities in couple of different ways. The first strategy is to evaluate your diet and be sure you are not lowering the pH in your mouth by sipping sodas or other acid drinks during the day. Even many bottled waters are acid so check it out on Google. A second strategy is to harden the teeth with fluoride products. I recommend getting a fluoride varnish (deep penetrating small safe volume) applied in our dental office every 6 months and then re-charging that daily with either a prescription fluoride (tooth paste or rinses available) or by using an over the counter fluoride rinse like ACT in addition to an anti-microbial rinse like Listerine. The third strategy is to use Xylitol products during the day. Saliva is supposed to buffer acidity and some people have poor saliva quantity (dry mouth) or poor saliva quality (acidic mouth) and using Xylitol (a natural sugar product that the bacteria that cause tooth decay can not metabolize to make acid) after meals or acidic drinks will help stimulate natural saliva and help neutralize acid. Xylitol comes in sprays, gum or mints. Check out http://www.xlear.com/what-is-xylitol/ for more info and products.