Trying to keep paranoia at bay here, I would like your input.
While growing up I had a dentist who put 15 Amalgams in my mouth. Looking back, I can remember him taking a sharp metal pick and pressing the pointy tip into the center of my molars, sometimes so hard that my neck muscles couldn't keep my head against the headrest. My jaw would be sore afterwards. I was very young and didn't know to question a "professional" or dentist. Now my logic tells me that applying a sharp metal pick with such force to the center of a tooth MUST have done damage.
I'll just cut to the chase here... I think he was intentionally causing cavities or holes/cracks so he could put in fillings and make money off it.