J. Thomas Russell, DDS, General Dentist at Yellow Springs Dental Care, wrote in a June 11, 2006 post "Teeth Don't Need Milk," on his dental practice website:

“Milk is an essential nutrient for bone. We need calcium in our diets at every age, to have healthy bone.

However, after a tooth erupts, calcium can neither be taken from nor added to the tooth–it is unavailable to the body. After the tooth erupts into the mouth drinking milk cannot ‘strengthen’ the enamel or any other part of the tooth. Our last teeth (the wisdom teeth) come into the mouth at around 17 to 20 years of age.”

June 11, 2006