Had a dentist try this on me when I was 16...told me and my mom (it was Medicaid) that I needed a Root Canal for my full mouth, that my teeth were "dead". I'm not sure what made me disbelieve him but I told him my teeth felt fine and that I was getting a second opinion. BTW: in the 34 years since, I still haven't needed a root canal nor do I have "dead" teeth.