Wine and Tooth Erosion:

Wine consumption is often overlooked as an irreversible cause of tooth erosion.  Wine is acidic (pH 3.5) and is often sipped slowly, allowing extended tooth contact.  Pigments from red wines are absorbed by the teeth leading to a darkened color.  White wines tend to be more acidic than red.  Both red and white wines dissolve the enamel from the teeth with resultant pitting, dark discoloration, and tooth sensitivity.