Ann, this looks like quite a good dentist in Bedford:

www.hallvtox.dircon.co.uk

I haven't checked with them, but I read they use diamondlite, use safety precautions (although I don't know about dental dam) and are very reasonably priced i.e. filling for £80-100, compared to say some others at up to £250.

They also offer accommodation if you need to stay over.