When our dentist went private years ago, under the Thatcher regime, they wrote and said, "Never mind, you can take out dental insurance at £12 per month (each)."
Now if Thatcher had said "We are going to improve NHS dentistry by imposing a dentistry tax, a flat tax of £12 per month on all adults", there would have been a riot.
But she did this in effect by driving dentists out of the NHS into the arms of the insurance companies.
How did she succeed? Because nobody likes going to the dentist. So it was not an issue.
NHS Dentistry should be protected and enhanced by imposition of a levy on sugar hypothecated to the service.