Replied by Ted (Bangkok, Thailand)
Tooth enamel can't re-grow but it can remineralize, reducing cavity sizes. Perhaps colloidal silver can often regenerate tissues and help enamel regrowth as silver is well known to cause dedifferentiation of cells or stem cell as Dr. Robert Becker mentioned in his book, The Body Electric. Often cavities are due to lack of bicarbonates to neutralize the acid from bacteria, and molybdenum which helps control pH, and perhaps xylitol which works twice better than fluoride, but yet it is natural and safer still. Perhaps adding xylitol might reduce cavities too. Ted