During a routine teeth-cleaning appointment, a nubbin of tooth chipped off under the dental hygienist's silver pick.

During a routine teeth-cleaning appointment, a nubbin of tooth chipped off under the dental hygienist's silver pick.

"Oh, I just knocked off a piece of your tooth," she said.

I don't pretend to know much about what dental hygienists do when they sit down behind a person's head and begin poking with this tool and scraping with that one. I keep my eyes shut and probably would fall asleep entirely if it weren't for the chance that the hygienist will suddenly blow air on my sensitive tooth.

Usually I spend at least part of my time in the dentist's chair speculating about the childhoods of dental hygienists. Some children love to play with hair; they're always standing behind their friends, combing and braiding and fashioning French twists. Do nascent dental hygienists love to play with teeth? At sleepovers, are they always twirling lengths of floss around their fingers and looking hopefully around for volunteers?

The hygienist who accidentally minimized my tooth was excellent, I should make clear; she was friendly and efficient and as sensitive as my sensitive tooth. In fact, after she realized I had a sensitive tooth (what gave it away was every muscle in my body tensing whenever she came near it) she dried the tooth with a soft cloth instead of using a blast of air. Wasn't that nice of her? It made me hope that she had plenty of friends in her growing-up years willing to let her examine their molars.

In any case, I didn't blame her for breaking my tooth. My teeth do their best, but let's face it, they're the same teeth that accompanied me through my late childhood and early teens, when I didn't abuse them so much as I challenged them at every turn: sno-cones against regular visits to my awful dentist, Dr. Shanewise, whose very name still makes me shudder with dread; caramel candies against junior high school orthodontia; a Juicy Fruit habit against regular brushing. My teeth took everything I threw at them and remained standing; am I going to complain if one of them shows a tiny bit of weakness now?

Anyway, one week later I was back in the chair, ready to have my peripatetic tooth chip replaced by something more durable.

"I think we can do this without anesthetic; it's not a big deal," the dentist said cheerfully. It was clear he expected me to go along, but I was not so sanguine.

I don't think so, I said, shaking my head. I suspect I was shaking it energetically enough to loosen the bolts on the chair.

No? Well, OK, he said, and a few seconds later my left jaw was numb and the dentist and his assistant were busy trading instruments while deep into a conversation about the assistant's son's car.

I shut my eyes. Thanks to Novocain and top-drawer equipment and the disappearance of old-school dentists such as Dr. Who Cares If It Hurts Shanewise, going to the dentist is truly a painless undertaking. I'd even bet this procedure would have been painless without the Novocain.

But it isn't the pain that frightens me. It's the anticipation of pain, the notion that while it may not hurt now, the drill might slide over a nerve two seconds from now, or a half a minute from now, or even a full quarter hour from now. Bracing oneself against the possibility of pain is exhausting. It knots every muscle and causes fingers and toes to clench whether or not pain ever materializes.

Give me Novocain, or any numbing agent, and I can fold my hands, cross my ankles and wonder what dentists want for their birthdays when they're children. Scalers and curettes? Round mirrors with long handles?

After I leave the dentist's office, the numbness in my jaw will continue to expand until my head no longer feels attached to my neck, but I don't mind. It's a price I'm glad to pay.

Margo Bartlett is a ThisWeek staff writer: E-mail mbartlett@ thisweeknews.com.