Tell him your bank account is still recovering from the last visit. He will be wanting to get yu off his list - they do that now if you haven't been there for a while - 2yrs is a long time, my dentist will strike you off if you leave it for 1 yr, so I have to go every 6 moinths.
I live in fear of having to have anything done - I had a gold crown fitted on the NHS and it cost 260 quid. If you aren't on benefits and you don't have much money, your teeth can rot in hell as far as they are concerned, it seems!