Green tea isn't only good for your teeth because of its fluoride content. It is also rich in compounds known as catechin polyphenols, which are effective at killing bacteria in the mouth responsible for gum disease and tooth decay. In fact, researchers at Tohoku University Graduate School of Medicine in Japan discovered that men who drank at least one cup of green tea a day were 19 percent less likely to lose teeth than those who didn't take their (green) tea time [source: Marshall].
Two other colorful beverages that are rich in polyphenols -- and therefore effective for battling decay-causing bacteria (although they can stain the teeth) -- are cranberry juice and red wine. Having a little cheese with that red wine after a meal is a good idea, because it neutralizes acid and produces beneficial saliva. In one study, those who regularly ate cheese had 71 percent less damage to the enamel than non-cheese eaters [source: Smith].
Another reason cheese is beneficial is that it is a good source of calcium, which also helps build strong teeth. Other good sources of calcium include canned salmon or sardines (their soft bones are a great calcium source), dark leafy green vegetables, blackstrap molasses, low-fat dairy, almonds, Brazil nuts and sunflower seeds.
More keen on topping off a meal off with something sweet and luscious instead of stinky and salty? Well, there's good news for you, too. In one study, an extract made from cocoa has been shown to be more effective at protecting teeth than fluoride [source: Tufts University]. Researchers believe the effect is due to the fact that cocoa contains theobromine, which can help harden tooth enamel. But remember, as with all health benefits derived from chocolate, the darker the better.
Other candy-style treats that help keep your teeth strong include pure licorice (as in the Chinese herb, not Twizzlers), which helps kill streptococcus mutans, and chewing gum, which produces saliva with a higher pH that is, in turn, effective in neutralizing decay-causing acids. Chewing gum made with xylitol is even more effective because streptococcus mutans consume the xylitol like sugar, but cannot metabolize it. The buildup of xylitol eventually becomes toxic to the bacteria.
Finally, teeth can benefit from foods that are rich in phosphorus -- like meat, fish and eggs -- and magnesium, which is found in spinach and bananas.