In BC (and I assume other Canadian provinces) the dental association publishes an annual fee guide. They recommend that dentists charge the suggested fees, but they do not require it. Many insurance companies use the suggested fees as limits on how much they will pay for certain procedures. But patients who are paying cash don't know how much the "suggested" rate is for the services they received -- unless they borrow a copy from their local library, since the dental association explicitly refuses to put the guide online. (Their argument is that the fee schedule is too complicated for patients to understand.)

So despite having nominally standardized pricing, in practice there's nothing keeping pricing standardized beyond what insurance companies are willing to pay for their clients.