Brushing teeth and tasting wine generally go together like raspberry jam and minty freshness, which is to say, eccch.
Professional wine tasters always have to put a little thought into when to brush. The best time to taste wine is in the morning, but no wine tastes good with a lingering hint of spearmint.
I like to brush my teeth after a post-lunch coffee, but can't do it if I'm going to taste wine in the afternoon. I'd rather show up for a wine event with coffee breath than unable to appreciate the first wines served.
Recently I discovered a toothpaste that leaves my palate more unaffected than any other I've tried: Desert Essence Citrus Fresh flavor. It's very mildly citrusy, and that's the note that it leaves in your mouth, instead of mint or cinnamon or fennel or ayurvedic herbs (tried 'em all).
Desert Essence makes two other flavors that I also like, a seaweed-mint that reminds me of the movie Green Slime and a cinnamon-cherry one that is the tastiest of the three, but doesn't have the same low-mouthprint effect. For wine tasters, the citrus one is the only one that's special. You can buy them at Whole Foods.
It's funny; rambling on about a wine or food I like is normal behavior, but for some reason it feels weird talking up a toothpaste. A conversation I had at a wine event, where the promoters swore that a certain brand of water was proven to be more neutral to the palate than all others, made me realize that my discovery was worth sharing. So if you taste wine professionally, check it out.