Your dentist probably never told you that teeth are able to heal themselves:
That’s how traditional cultures such as the Inuit can wear their teeth down to the pulp due to chewing leather and sand-covered dried fish, yet still have an exceptionally low rate of tooth decay. It’s also how the African Wakamba tribe can file their front teeth into sharp points without causing decay. Both cultures lost their resistance to tooth decay after adopting nutrient-poor Western foods such as white flour and sugar.
So, it looks like there’s a good reason your dentist never told you that teeth can heal — in his experience, they don’t. Americans — especially those who get cavities that need healing — eat a modern diet full of white flour and sugar:
When enamel is poorly formed and the diet isn’t adequate, enamel dissolves and decay sets in. Tooth decay is an opportunistic infection that takes advantage of poorly built or maintained teeth. If the diet remains inadequate, the tooth has to be filled or removed, or the person risks more serious complications.
Edward Mellanby had this to say — about his wife’s research on dog teeth — in his Nutrition and Disease:
Since the days of John Hunter it has been known that when the enamel and dentine are injured by attrition or caries, teeth do not remain passive but respond to the injury by producing a reaction of the odontoblasts in the dental pulp in an area generally corresponding to the damaged tissue and resulting in a laying down of what is known as secondary dentine.In 1922 M. Mellanby proceeded to investigate this phenomenon under varying nutritional conditions and found that she could control the secondary dentine laid down in the teeth of animals as a reaction to attrition both in quality and quantity, independently of the original structure of the tooth.
Thus, when a diet of high calcifying qualities, ie., one rich in vitamin D, calcium and phosphorus was given to the dogs during the period of attrition, the new secondary dentine laid down was abundant and well formed whether the original structure of the teeth was good or bad.
On the other hand, a diet rich in cereals and poor in vitamin D resulted in the production of secondary dentine either small in amount or poorly calcified, and this happened even if the primary dentine was well formed.
What about humans?
Drs. Mellanby set out to see if they could use their dietary principles to cure tooth decay that was already established. They divided 62 children with cavities into three different diet groups for 6 months. Group 1 ate their normal diet plus oatmeal (rich in phytic acid). Group 2 ate their normal diet plus vitamin D. Group 3 ate a grain-free diet and took vitamin D.
Those three groups seem odd — where’s the control? — but the results are interesting:
Vitamin D does seem important for dental health.