It came up in conversation that someone’s dentist had claimed that the eating of cheese after a meal being good for the teeth is a myth.
A few minutes with Google Scholar shows that there is fairly extensive research showing that cheese has cariostatic properties, in that it acts to prevent or delay tooth decay. The eating of small pieces of cheese has been demonstrated to harden tooth enamel, and the consumption of cheese (within a meal) increases the concentration of calcium in dental plaque which is one of the suspected mechanisms for the cariostatic action of cheese.
As with all things scientific there are details that matters. Some cheeses contain bacteria which are thought to discourage “bad bacteria”. Hard cheese is generally better than soft.
Milk has similar but less pronounced cariostatic properties. Cow’s milk being the best of those compared in most of the studies (generally the comparison is with human milk, and infant formulas of varying compositions, since this is the group who consume most milk, and across all cultures). The effects in milk seem to be independent of fat content. Whilst there is much discussion about lactose in milk, cow’s milk appears not to be cariogenic despite the lactose..
Cariostatic properties doesn’t mean it necessarily prevents decay completely, and it is not a substitute for proper teeth cleaning. On the other hand if like me you do enjoy a little cheese after a meal you can be assured that it is good for your teeth if not your waistline.
This entry is not a substitute for medical advice, if in doubt consult with a dentist or doctor (but do check what they tell you).
The reference cited doesn’t cover all the points mentioned. I’ve tried to convey essential or interesting points from the information I found, not write a science paper.