It turns out that your dentist was right about something else: Fluoride matters. In fact, according to the American Dental Hygienists' Association, water fluoridation has reduced tooth decay in the United States by 50 to 60 percent since World War II.
Fluoride, a natural element, works by helping make the crystals that form tooth enamel more durable. In short, it remineralizes teeth and helps them become more resistant to acid and decay. It can also help stop bacteria from producing so much acid in the first place.
Fluoride can be incorporated into the teeth in two ways. Topical fluoride is applied directly to the teeth through such mediums as fluoride toothpaste, dental treatments and mouth rinses. Systemic fluoride is directly ingested into the body through water or fluoride supplements, and bathes your teeth through its presence in your saliva. Fluoride can also be ingested systemically through what we eat. Foods with particularly high fluoride concentrations include fish and tea -- especially green tea, which has twice the concentration of fluoride than its black counterpart.
One of the issues facing adults is that fluoride consumption has been declining with the increase of bottled water consumption. Although some bottled waters do contain the element, many don't -- especially those that are treated with a reverse osmosis process that can take out as much as 95 percent of the fluoride from water. So, if your choice of bottled water doesn't contain fluoride, you'll want to be extra certain you're getting it through your toothpaste or other means.