I used a combination of oil pulling and a 15 minute session daily of swishing comfrey root aka knitbone around my mouth to try and help my teeth recover after a long battle with bulimia. Luckily they did not take too much damage but the enamel on the front ones were drastically thin. It did not restore them back to normal obviously but it made a significant improvement and gave them a stronger coating, reducing the pain from sensitivity drastically.

I need to do another round of it actually! But it did really help.