sorry, didn't mean to say that cavities can't be healed. I only meant that new teeth are in question to be regrown. I misunderstood. The dentine can most likely be regenerated, but question as to whether enamel can grow back. Just watched a Utube video last night, showing what appears to be an optimal cavity treatment plan. First air abrasion of most of the decay, then ozone treatment to kill bacteria, then simple sealing of the area with flowable resin. Little if any real trauma or typical drilling damage done to the tooth.
Just purchased a medical grade oxygen tank supported ozone generator. Am experimenting with it. Quite interesting stuff, as it promotes cell health at the same time of obliterating viruses, bacteria, fungus etc.