I always thought it was the city water that was supposed to be bad for you.
I'm afraid one of my previous dentists killed them. I never had many problems with my teeth until I asked a dentist to 'clean' them after an exam. I think he scraped through the outer protective enamel. Within a year afterward I started getting cavity after cavity. When I went in for my 1st heart surgery the hospital mandated I have any dental problems addressed before the operation. The hospital's dentist took one look in my mouth and said "My God, what kind of dentist have you been going to?" He didn't elaborate but I assume there were signs of some bad work having been done.