The NHS direct website is useful in theory but not really in practice - I tried last week to register with an NHS dentist but of the 10 listed on the website anywhere near me who were supposed to be taking new NHS patients I called 8 -and not a single one was actually taking anyone on. So generally its a bit of a waste of time and phone calls. It would be useful to know if you do find one in the Borough area though!
I've been going to see Mr Kwan at The Elelphant for 20 years or so with no complaint. Under the bridge at the top of the New Kent Road. I have experience of Mr Annobil too and I would recomend Mr Kwan.