Dentist

Any medical practitioner can charge whatever they think the market will bear so long as they charge at least the legally laid down minimum.
You can always check out the website of your mutuelle re: reimbursement. Mine refunds for scaling but it's not impossible that my dentist simply lumps everything together under one heading.
NEVER accept a dentist telling you that such-and-such is not covered by the mutuelle; always insist on an official receipt and let the mutuelle tell you if it is not covered.