However, I do believe that genetics also plays a large role in predisposition to cavities, with or without a healthy diet.
But, here I am writing this and here you are reading it.
Just example, a person with hyperthyroidism will have much more issues with teeth than someone who doesn't.
Lactic acid + tooth + time = cavity
Sufficient mineral content in saliva and replacement of hydroxide by fluoride in the bioapatite tooth matrix affects the time factor.
So there are four ways to completely avoid cavities.
- Annihilate the mutans-type bacteria in your mouth, and prevent recolonization.
- Do not eat sugars.
- Remove all your teeth.
- Die.
If your saliva is well buffered and mineralized, it would be very rare for pH to dip below 5.5 and have minerals leach out of the teeth. Diet would certainly also help in this respect, especially with regard to calcium, phosphate, fluoride, vitamin D, and vitamin K.