I once had an argument with a guy who thought that fluoride didn't work, because if it did dentists would tell you not to use it. After all, why would they undercut their own business? My counter-argument that dentists just want to help people was met with bemused skepticism, as was my speculation that they probably make more money from routine cleanings than from drilling cavities.

I am now fully convinced that the dentist lobby is keeping the caries vaccine from us.