We have known for many generations that sugar, particularly when processed, is bad for our teeth. But it is misleading to say that it is the only cause. There are other factors involved.
Lack on minerals in the diet, particularly magnesium, calcium and phosphorus, will cause problems. We have known for a while that calcium was an issue, and encouraged children to drink milk. But lack of any of the minerals will leave teeth weaker and prone to decay.
Lack of fat soluble vitamins, such as A, E, K and especially D, will weaken teeth and probably cause gum problems. These vitamins combine well to benefit health, though if one is deficient the others cannot compensate. We need all these vitamins together.
Recently it has been discovered that Phytic acid in food both blocks the absorption of minerals in our diet and leaches minerals out of bones and teeth. Processes such as sprouting or fermenting seed, beans and grain significantly reduce phytic acid. These processes were once popular in agricultural societies, but have fallen out of favour with modern processing and cultural habits.
It is a pity that the best dietary intentions in the world are compromised by anti-nutrients such as phytic acid. But this can be altered. Fermentation, soaking and sprouting of beans, nut and grains (while slightly time consuming) can make a significant difference to the way out bodies absorb nutrients. This should allow us to derive the maximum benefit from natural and healthy food sources.
We know to avoid sugar and brush our teeth. We should also know to eat the healthiest diet possible. Our society had lost some good habits over time. If we reintroduce these habits, or develop healthy habits of our own, we can reap the benefits in every part of our lives.