ToothBlues

If it cost more to prevent tooth decay than to fill your teeth you should gamble on the cavities. That appears to be the name of the game in dental insurance when it comes to their policy on sealants.

Quick, what's the biggest reason why tooth decay in American has declined sharply over the past 50 years? Most people would cite the use of fluoride. But there's another factor: Sealants.

Sealants are a plastic coating that dentists can apply to protect molars with deep grooves in them that are impossible to clean. They act much like fillings, except they bond with the surface of the tooth to protect those tiny crevices from plaque and decay. Many people have these teardrop-shaped grooves in their molars that practically guarantee cavities over time. And once children get their permanent molars they're often given sealants to protect those teeth.

Sealants have done a tremendous job of improving public health by reducing the number of cavities. The problem is that they can wear off - or flake off - from the tooth after just a few years.

A sealant might last 40 days - or 40 years. But when they go, they're gone - and insurers won't pay a dime to replace them. The coverage for sealants - a key to preventive dentistry - is once per lifetime.

The sealant on one of my daughter's molars detached in the last year or so. The dentist didn't replace it - a $40 cost - because it wasn't covered by insurance. Now, at 15, she has a cavity in one of those hidden grooves. So we paid to have a filling - and paid out of our own pocket to have the sealants reapplied.

I asked the dentist whether consistently monitoring sealants during checkups and applying new ones as they failed would prevent tooth decay - in adults and children. "Absolutely," he said.

He says that insurers are probably afraid to offer unlimited coverage of sealants. They worry that doing so would give dentists a blank check to rack up bills by sealing and resealing patents' teeth at every checkup.

But there are also some cold, hard actuarial calculations at work. Once you're out of your teen years the incidence of cavities decreases. Insurers often pay 100% of the cost of sealants. But a cavity might cost $120, of which most policies typically pay just 50% - or less.

You're unlikely to get a cavity in all of those unprotected teeth. But you'll probably get one or two - if you're lucky. So, rather than pay to put new sealants on all of your teeth, it's cheaper to just pay for the cavity or two you might get a few years later. It's like a game of Russian Roulette, only with teeth instead of bullets.

In the end, the insurer pays less. But you lose. The insurance equation is not a social contract to promote public health. It's all about money and deferred costs. In this calculation the value of having perfect teeth simply is not a factor.

My recommendation: If you have sealants, have them checked regularly. If they're worn out, pay for new ones.

We're paid out of pocket to have my daughter's reapplied. I think of it as a lifetime investment. I have had mine reapplied several times - at my own cost - since I had my first ones in grade school. At 48 I have no cavities in any of my molars.