I have a high threshold for pain, I’m told by those who should know — health care providers whose job involves causing pain, e.g., sliding long, cold, pointy metal implements up a nostril.

So when a tooth started to object to hot and cold liquids and foods shortly after my dental examination and cleaning last week, I was inclined to ignore it. After all, tooth pain often comes and goes for no discernible reason. Only once did the pain not subside, forcing me to break down, see the dentist, and find out that I needed a root canal (said the endodontist’s assistant after the procedure, “Weren’t you in agony? There was blood and infection everywhere under there.”).

This time, however, I waited only a few days instead of a few months, even though the pain was intermittent and not that bad. Why? Because my overactive imagination started to feel millions if not billions of bacteria pouring into the vulnerable spot, setting up housekeeping, and eroding the structure away until the nerve was exposed. When I ate or drank anything, I could feel the resident bacteria inviting in more friends, saying, “Welcome! Bienvenue! There’s plenty to go around!”

To quell the greedy, destructive masses, and my imagination, I made an appointment with the dentist.

The dental assistant poked, prodded, and even pounded around my upper left molars, where I thought the problem was, then took x-rays. The moment I bit down in preparation, I realized the unhappy spot was not in the back, but in the middle. The dentist, who sees all from her office via computer, directed the second set of x-rays at #14 and #15; a shadow turned up. After she took her turn poking around, she came to the conclusion that it would be prudent to replace both old silver fillings. Prudent — and painful. And costly.

An hour later, she was almost done, telling me that now I have more filling than natural tooth in that area. She wanted to test my bite with the new fillings, but apparently I was too quick to snap. “Not yet; that’s my finger,” she admonished, although when I apologized she said that there was no harm done; she’s gotten “pretty quick” herself.

A few minutes later, her hand got tangled up in my hair. “Hmmm, you bit my finger; I pulled your hair,” she said. “So now we’re even,” I noted. She laughed nervously.

Of course, the last laugh was hers (in her office) when the office manager presented me with my portion of the bill.

Ouch. Perhaps I’m more sensitive to pain than I thought.

Note: Don’t get the wrong idea. I have a great dentist, worth every painful dollar.