Yes. As in America there is gap insurance which people buy to cover the difference in reimbursement between the state insurance system and the fees of some private doctors.
I guess no-one has informed my dentist that he does not perform careful reconstruction of teeth to prevent their loss after trauma. I think I will not tell him, for fear that if he were to discover that dentists in France only extract teeth but do nothing else more sophisticated, he will stop.
Go to a dental surgeon for a single or double root canal and crown, which takes 4-7 hours of work, and see how much you get back from the Sécu...it will be miniscule, as if he had worked on your tooth for 1/2 hour.
On the other hand, private dentists in Paris, many of whom have received post-graduate training in the US, charge about the same amount as dentists in any large American city.