Keep Em Pearly White

By: Ted Huppert DDS

Everybody knows about tooth decay, right? Those of us who are old enough remember the commercials that said, “Look, mom, no cavities!” But what is tooth decay exactly?

Tooth decay isn’t decay in the usual sense of the word. The tooth is not literally rotting away. Decay is actually losing a race.

The teeth harbor lots of bacteria. Lots! Tens of millions of them, and they double in number every few hours. You know that film that you can feel on your teeth when you wake up in the morning? It’s alive!

All these bacteria—and there are dozens of species in the mouth, although only a significant few seem to be the prime movers in tooth decay—have one thing in common. They all need carbohydrates to survive. They must absorb sugars through their outer walls for nutrition. They then happily metabolize the sugars for energy, just like we do, and they excrete waste products, just like we do. The waste products that the bacteria excrete are highly acidic in nature. And if we allow enough bacteria to accumulate in one spot, the amount of acid they produce can dissolve tooth enamel.

Fortunately, we have saliva! The saliva is chock-full of calcium and phosphorus, so the teeth are constantly bathed in a mineral-rich fluid. These minerals are deposited into the areas of the enamel that the bacterial acids have dissolved, so the tooth re-hardens.

Now, the problem is, the bacteria dissolve the enamel a lot faster than the saliva can re-harden it.

Let’s say that I take a drink of soda—let’s make that Mountain Dew, which is the most decay producing soda—and rinse it around my teeth by swallowing. The bacteria there start to party down! That sugar goes right into them and they start chugging away like little factories, pumping out acid like crazy. If I don’t drink any more soda, the sugar from that one sip stays in the groove between my gums and teeth for about twenty minutes, and all the while, acids are dissolving my enamel. It will take my saliva an hour or so to re-harden the enamel I lost in that twenty minutes. But of course, I don’t wait an hour between sips of soda. A few minutes later, I take another sip. To the bacteria, that new sugar jolt is like a set of de-fib paddles—“Clear!” ZAP!—and away they go again. Okay, now I need two hours to remineralize. A minute later, another sip. Now, it’s three hours to recover. Get the idea? Eventually, enough enamel is dissolved that the saliva cannot catch up. That’s what tooth decay is. The tooth has lost the race to remineralize. The saliva is the tortoise and the bacteria are the hare. Only, this hare never sleeps. It always wins the race.

That’s why I cringe when I see those young check-out clerks in the grocery store with a half-empty Dew beside the cash register. I know that they’ve been sip-sip-sipping on it since the start of their shift. And I know that the next time they see their dentist, they’re likely going to have some decay.

Mountain Dew is by far the worst offender, as far as sodas go. Studies show that Dew dissolves enamel twice as fast as any other soft drink. And they can’t figure out why. It isn’t the acid. The pH (acidity factor) of Dew isn’t any different than other sodas. And it isn’t the sugar, because—brace yourself—diet Dew does it, too. So, because of the combination of ingredients or whatever it is, Dew and diet Dew are the most cavity producing sodas.

I know from experience. Whenever I see a young adult, say teens through mid-twenties, with lots of decay at the gumline, I ask, “Do you drink Mountain Dew?” And they all get that deer-in-the-headlights look, like I’m psychic or something. Usually, they say, “Oh, yeah, I drink it all the time.” Ask any dentist. There has even been some talk of officially calling rampant gumline decay in young people “Mountain Dew mouth.” I’m sure the Pepsi folks would love that.

So, what can you do to prevent decay? Limit sodas and high-carbohydrate snacks. Without fuel, the bacteria can’t do much. Brush and floss daily to keep bacterial colonies stirred up. This will reduce the acid in any one spot on the teeth. And use a fluoride toothpaste. Fluoride speeds up the remineralization process and creates a harder surface on the teeth. There are toothpastes available now that also have a high calcium content and that can help, too.

By the way, there is a worst-known food for causing cavities. It’s those super-sour jelly candies that kids like so much. The super-sour is Vitamin C, which is ascorbic acid (acid!) and the sticky jelly holds that acid deep in the grooves on the chewing surfaces of the teeth. What could be worse? Nothing!

Doesn’t anybody snack on apples any more?