It would not be cost effective to hire a lawyer for this. I would get the statement from the prosthodontist and then file against the dentist in Small Claims Court. In Small claims Court neither side can have a lawyer and an award can be made up to $7500. There are advisers there to help you through the steps. I would also file complaint with the California Dental Board. You can contact the at www.dbc.ca.gov. They are the disciplinary board for dentists.