I came out of the Powell Street BART station a little after nine and started walking toward Union Square. Department stores and tourist boutiques shared the street with older businesses that evoked the San Francisco of Herb Caen, if not Dashiell Hammett. The night’s fog still hung overhead and thanks to the mayor’s recent crackdown on the homeless, the urine stench was at a minimum.

I arrived at an office building on the 400 block of Sutter Street and took the elevator to the 19th floor. Around the corner and down the hall was the dental lab. I was sent there to determine the matching color for a crown on my upper canine. The darkest my dentist had to choose from was “coprophagous chain smoker,” which simply wouldn’t do. I was instructed to go down to the lab so they could pick something suitable from their “Shane MacGowan” collection.

The lab had no real front office to speak of, just a secretary at a desk with paperwork piled high in several places. I had a clear view of of the back where little white plumes of dust rose from the workbenches of technicians shaped fake teeth with miniature belt sanders.

I was quickly introduced to the lead tech, an older Filpina whom I’ll call Imelda. She led me back to her work area where, on command, I bared my teeth like an animal.

“Tectracycline,” she said, and waved over an assistant for a second opinion.

“Oh wow,” said the assistant.

I told Imelda how I was given tetracycline when I had my tonsils removed in 1965 and it had discolored my teeth.

“This is going to be difficult,” said Imelda. “The discoloration is not not uniform. Have a look.”

She then handed me a mirror. I hadn’t really noticed it before (or maybe I just didn’t want to), but my teeth contained a blended strata of hues. It was like a Rothko painting.

“To match all these colors, I’m going to need you to come back after the crown is molded. I think I can do it but it won’t be easy.”

Naturally, I consented. Far be for me to keep Imelda from what will no doubt prove to be her masterwork. Also, I could treat the whole experience like a modeling gig. I liked that. It made me feel glamorous.