Hi. There are two dentists in London that I know of that use safeties and diamondlite:

David Harvie Austin (trained under Hal Huggins)
David Cowan

Both are in Weymouth Street, I think (which is just off Harley Street).

Apparently teeth can heal themselves to some extent when the caviiity has been cleaned. It takes about 2 months. I guess it's a siiimilar process to healing broken bones, which take around the same amount of time. The teeth are temporarily filled with something and then with permanent material.