Where we live (somewhere in Europe), all the costs, procedures, etc. are standardized by the health insurance companies (which are in turn strongly regulated), so it is really hard for dentists to overcharge without getting in hot water with the insurance companies. The insurance also pays a good chunk of the ongoing dentist costs (though IIRC we have some extra dentist insurance). We go twice a year for a checkup and cleaning (last few bills were 12 Euros after the insurance paid the rest). Drilling (with anesthetic) and filling with a composite is typically 25-30 Euro out of pocket after insurance.
Going every six months for a checkup is really nice, because thing rarely get out of hand (+ you have whiter teeth after cleaning, which is especially nice for tea addicts like me :)) and they x-ray every two years or so.
In USA insurance companies do have standard code and cost for procedure. Then I found out my son dentist was charging the insurance for « sealant » on all adult teeth every 6 month when my son in fact did not have adult teeth yet. I tried reporting as fraud to to the insurance company and they did not care at all and did nothing.