My dental practice looks modern and very clean, and has a TV. They do regular free samples of toothpaste too, ideal for taking travelling.
A lot of dental practices here are both private and NHS. The orthodontist I used to go to did both, and he had much better equipment than the NHS hospital I went to.
Maybe it works well for dentists because...actually, I can't think of a reason.
On the other hand, the hospital I went to for a blood test that was previously NHS, then run privately, was an absolute shambles. It was terrible, and there were so many people waiting around. I think it was one staff member doing blood tests plus other things.