Well, how much money did they make selling probiotic mouth wash?
I'm pretty sure if they had gone with curing all the world's cavities I would have heard of them. The brand recognition alone would be worth more than a probiotic mouth wash company.
Very unlikely there was a miracle cure that was left on the table because founders wanted to sell mouthwash.
It isn’t that simple. Say you believe that you have a miracle cure, but it will take a billion dollars to go through all the medical trials. And at the end, you could find out that it isn’t a miracle cure or could end up having too many side effects, then you are out a billion dollars. You just might not have the pockets deep enough to risk it. A probiotic mouthwash may have the potential for a fraction of the returns, but may only cost 5 million to bring to market.
That's a general problem in health care and why governments should be more involved in funding and supporting these kinds of solutions.