I went to the dentist today for a check up and the dental hygenist told me that wine tasting can be bad for your teeth, and not just in the turn-them-black way. The acid in the wine, or the acid in anything, eats away tooth enamel especially at the gum line. She suggested carrying a little bottle of floride rinse to use after tasting wine.
Good idea! This is one of the advantages of going to a dentist in a wine region.