Okay Liz---deep breath!
Sounds like an EXCELLENT dentist, who has taken on board your situation, doesn't want to worry you unnecessarily (that's lousy spelling, I think!), but is taking his duties very seriously.
I'll try the 'LIz's advice to others' bit FOR you!

" Read the boards about all the people who've been worried about lumps/bumps/patches and see how many have turned out to be NON-cancerous--lots lately!"

But hell, my 'urgent' MRI and biopsy didn't happen very fast, this being England, but I do know that Leeds has an excellent reputation--it's also a teaching hospital.
I have a friend with a cleft palate who has recurrent surgery there and when I was facing the possibility of major surgery to my jaw, told me about the wonderful results she'd seen at Leeds maxioll-facial unit.

Personal opinion is dentist is making sure that history does NOT repeat itself--he's not negligent!

If you haven't been 'summoned' before next weekend, you sure do need a day away!!

Brenda