Think about what your teeth are like just before you brush them.
They’re probably a little on the gnarly side. Think particles of food, predigested by saliva. Think of bacterial slime coating your teeth. Think of anaerobic microbes partying in your periodontal pockets – bacteria, viruses, yeasts, all doing the happy dance because they’ve been fed right along with you and left alone to do their microbial thing for hours.
Time to end their fun.
You get your trusty toothbrush and smear some paste on it. That paste might contain some antimicrobial stuff, or medicaments to encourage remineralization or decrease sensitivity, but the main thing it’s got is grit. That’s because its main job is to help break up the microbial colonies, giving them something else to do besides multiply and generate the acidic waste that can eat through enamel and cause cavities.
The physical action of brushing is what does most of the work. Toothpaste just makes it a little easier.
After you brush, you should floss – or before you brush, for that matter. The main thing is to do it, since brushing cleans only about 60% of your tooth surfaces. You need to floss or use a proxy brush to clean the areas that brushing misses.
All the while, you’re loosening and moving microbes and debris around in your mouth. So when all’s said and done, wouldn’t you want to give your mouth a final rinse to clear things out?
Sure, you would.
Yet there are indeed some dentists who say, Hell, no!
Why? As this one states, you don’t want to lose all that precious, precious fluoride your toothpaste contains – presuming you even use a fluoridated paste at all. Why would you ever want to rinse it off your teeth? Leaving it on longer, they say, gives it more time to work its magic.
Of course, as biological dentist Dr. Bill Glaros has said, 
Is fluoride something you really want to leave in your mouth for an extended period of time? Excessive exposure to fluoride can cause fluorosis, discoloring and weakening your teeth. And if you swallow some of it? Ingesting fluoride can cause a number of serious health problems.
Perhaps unsurprisingly, the don’t-rinse dentist is for fluoridation, as well – despite the evidence that fluoride has no positive systemic effect. And this raises a question: If your water is fluoridated, so what if you rinse away the toothpaste? You’ve just replaced one dose with another.
We say rinse – and avoid the fluoride when and where you can. Your teeth are better served simply by good nutrition, regular hygiene and an overall healthy lifestyle.
Image by Angelo Milioto , via Flickr