Well, it's nice to see the old British teeth stereotypes rolled out here again. For the record, though, the above commenter from Belgium is pretty much on the money. Back in the 1980s, NHS dentristry worked: appointments and treatment were easy to get and available to all. Since the 1990s, though, many or even most dentists have moved into private practice, depriving NHS patients.
Incidentally, though, in my experience the NHS dentistry crisis is to an extent reserved to more affluent areas. My parents live in a leafy London satellite town where there are now no NHS dentists available, and my friends in a rather nice part of West London have the same problem. Living in a rather less affluent corner of SE London I have a choice of four NHS dentists within walking distance.
PS - believe it or not, I've never heard of anyone here attempting DIY dentistry and, yes, I use toothpaste (it arrived on these shores last year, along with Jazz and the mass produced automobile - it's as if we're living with the Jetsons now, I tell you).