Time-saving method for the fabrication of a definitive cast for an implant-supported prosthesis

Abstract

Conventional methods for fabricating an implant-supported overdenture or an implant-supported, fixed complete denture involve a series of patient visits. Because these visits occur in sequence, each visit depends on the accuracy of the previous visit and influences the accuracy of subsequent visits. Any procedural errors during these visits could compromise the fit of the definitive prosthesis. 1,2 The first step in achieving an accurately fitting, passive prosthesis requires capturing the 3-dimensional intraoral relationship of the implants with an impression. The accuracy of this impression procedure has an essential role in the prosthesis-implant adaptation. 3-5 Although several strategies have been suggested to enhance precision when making the definitive impression and cast for an implantsupported prosthesis, 6 it appears that absolute accuracy is currently not attainable. 7,8 A number of implant impression techniques have been described. 9,10 Most implant impression techniques have 1 feature in common, whereby impression material is present between the implant impression copings and the custom tray. The presence of this impression material produces resiliency in the system, and this lack of a rigid connection to the tray may result in an inaccurate cast. This article describes a time-saving, step-by-step technique designed to achieve 4 objectives with accuracy in a single clinical visit: (1) impression of the soft tissue, (2) impression and position of the implants, (3) registration of the maxillo-mandibular relationships, and (4) arrangement of the artificial teeth. The use of a verification jig 11 has confirmed the accuracy of this impression method.