Two-stage impression technique for overdentures.

Overdentures are supported by hard tissue and resilient tissue. Optimum distribution of functional load between these different tissue types is a challenge. A two-stage impression technique is proposed to eliminate much of the need for finished denture base modification. A first stage impression is made of the resting form of the soft tissue and is used to make a mucostatic metal base. A second impression is developed under occlusal pressure with modeling compound applied to the border and the surfaces of the metal base overlying the abutments. This procedure establishes border seal and relates ridge tissue displacement to the abutments. A final cast is made by using the metal base and modeling compound. Heat-cured acrylic resin is processed to the metal base on this cast. Adjustment of the tissue surface of the base is limited to surfaces overlying free marginal gingivae and axial surfaces of the abutments.