Consider chewing Xylitol gum after eating. Xylitol directly fucks up the bacteria that cause tooth decay. Make sure to get a brand that is mostly Xylitol (I like Pur).
However, be careful if you have a dog, because xylitol is super poisonous to dogs!
Chewing any sugar free gum after eating is good. Chewing the gum increases saliva production, and the saliva is good for a lot of reasons. It breaks down any food and plenty of bacteria, as well as balance the pH levels in your mouth.