I was reading a dentist's website the other day and came across a discussion of how acidic foods and beverages, by eroding the enamel, make the teeth more susceptible to staining by wine and deeply-pigmented foods such as berries. The article noted that even drinking white wine could potentially increase the staining of teeth because of the wine's acidity.
I later found an interesting report in which researchers showed in the lab that cow teeth soaked in black tea for an hour didn't become stained unless they had been previously soaked in white wine.
The article on the dentist's website went on to advise against brushing your teeth right after drinking wine because the exposure to the acid in the wine makes the teeth more vulnerable to abrasion. Instead, you should wait at least an hour before brushing. It might also help to drink some water, or to eat some cheese. According to the article, eating cheese helps to neutralize the pH of the mouth and also stimulates saliva production, which additionally helps reduce the mouth's acidity.
I don't drink wine, but I do drink a lot of juice and eat a lot of fruit. I also drink a lot of tea with - gasp - lemon juice. Now I am worried about all the damage I've been doing to my dental enamel over the years.
I guess I need to start eating more cheese after drinking the fruit juice and the lemon-flavored tea?