Dental related query

Go on your mutuelle's website where they list standard costs.

@R.Harris
Your mutuelle's website lists standard costs. My mutuelle's does not so you cannot assume that all mutuelle's websites list them.
However, www.riziv.be is the government site which lists the official minimum price for each procedure and the amount which will be refunded by every mutuelle. The RIZIV site is in Dutch but there is a clear link to the French version of the site.