I agree with what you write, but I'm also spitballing stopgap measures: Are there downsides to having governments instead contract healthcare capacity? Has this been tried?

By this I mean that instead of the government paying each hospital (or in this case dentist) for each procedure, the government pays each hospital (or dentist) to keep a certain capacity for each kind of procedure available. The hospitals are obliged to provide up to that capacity at no extra cost to the government. Any demand beyond it, goes into the backlog (and turns into a political issue).

Surely I'm missing some downsides…