I don't know why some posters think it's a laughing matter.
To answer the OP, I don't know anyone but did know someone who had almost a full set of dental implants done in Hungary and was very pleased with the results. I also met a woman who had a facelift in Thailand about 10 years ago - she looked great, not silly, and said the hospital was state of the art and all was well. So surgery abroad can work out but no doubt things can also go very wrong.
I suppose like everything else which you are paying out good money you need to do a lot of research and go on recommendations - maybe Mumsnet, with its much larger membership, would be a better place to enquire.