Asphalt is a very durable substance. However it is still under constant assault from sun, rain, temperature changes, salt in winter, physical stresses...
Our teeth are also subjected to extraordinary stresses. Chewing itself puts high repetitive mechanical stresses on teeth. There are drastic temperature changes as we bounce between the heat of the corn on the cob and the burger, to the cold of the salad, or the iced tea. There are sugars and salts and hard popcorn kernels and gritting when we hit a baseball. (Next time you go to the batting cages, take note of how hard you grit your teeth together as bat connects to ball. It's astonishing!) Some of us even grind our teeth every night. Or during the day, when your boss wants those TPS reports yesterday and you got a letter from the IRS calling for an audit and your son sends you a cryptic text that seems to indicate that the water heater is leaking but he's going to the skate park now...
It all adds up, and yet the biggest threat to the health of our teeth is sugar. Our Caries Clock explains it all quite well:
High frequency sugar intake is the overwhelming causative factor of cavities. They can occur anywhere on teeth but there are some main areas where they are most common.
Interproximal or between-teeth cavities can really damage a tooth; here is a large, obvious one:
Yet perhaps the most common place for cavities is in the grooves on the tops of our back teeth. My own tooth, no cavity in those grooves on the biting surface:
Those deep grooves are the other main place that cavities occur. Many years ago, in the 1920's and 30's, when the roles of sugar intake and oral hygiene in cavity formation were not so well known, it was estimated that over 95% of back teeth present in the American population either had cavities or fillings in their grooves.
There are many preventive strategies aimed at reducing the chance of tooth decay. The greatest is to limit the frequency of refined sugars in one's diet, a la our Caries Clock. Another is cleaning the bacterial plaque from our teeth each day, and seeing a dentist and hygienist on a regular schedule for professional cleaning of the surfaces of each tooth. We can also employ fluoride to strengthen the enamel against cavities.
Another way of protecting those grooves from decay is the dental sealant. This is a composite resin filling-like material. The difference between a sealant and a restoration is that there is no drilling, and thus no need for anesthesia, when a sealant is placed. They are essentially painted on to the tooth and stay there because of the power of dental adhesion. We can make our dental materials stick very well indeed these days:
Here are views of sealants in place on two six-year molars, an upper and a lower one, while orthodontic bands are in place:
The grooves are blocked out, sealed, and it makes it very difficult to get a cavity in the top surface of the teeth. Not impossible, any system can be overloaded, in this case with too much constant sugar use. But it's nearly impossible to get a cavity in the grooves of a tooth with a sealant in place.
Between-tooth cavities? For now, there is not a predictable way to prevent decay. Flossing and moderation in diet are the best strategy. But on the biting surfaces of back teeth? Sealants rock.