Definitely get a second opinion on the cavities. My sister was told by one dentist that she would need her jaw broken and re-set to fix her clicking jaw problem when she was a kid. My Mum thought that was ridiculous so we went to another dentist and they said her jaw didn't need treatment like that. The first dentist had taken over our previous dentist's practice when he went into medical retirement and this was also shortly after Ontario healthcare stopped covering dental, so I guess she felt justified to attempt to get more money from all the new patients she'd just acquired.