[Why should we use plaster for the prime impression in complete removable prosthodontics]

This thirty years literature review about removable complete denture prime impressions show that the plaster static impression is better. This product doesn't induce abnormal pressure on the biologic and anatomic support structures of the prosthesis. The plaster for impression physical properties is adapted to reproduce the details needed by the laboratory to manufacture the individual impression tray for the definitive functional impression. The only precaution is to follow the method. Our clinical experiences advise us to propose RIGNON-BRET (10, 11) simple plaster impression techniques. The one case where it is forbidden is when the patient has recently been treated by radiotherapy. All the other materials induce irritated pressure on the alveolar bone and consequently the second functional pressure added the stability of the denture may be defected.