Diagnostic waxing transfer from diagnostic casts to soft tissue definitive casts

Abstract

aAssociate Professor, Division of Primary Oral Health Care; Director, University of Southern California Center for Dental Technology. bSenior Dental Technologist, University of Southern California Center for Dental Technology; Division of Primary Oral Health Care. cAssociate Professor, Division of Primary Oral Health Care; Don and Sybil Harrington Foundation Chair of Esthetic Dentistry. (J Prosthet Dent 2008;99:•••-••) Fabricating quality anterior esthetic restorations, such as porcelain veneers and crowns, requires the fabrication of a soft tissue definitive cast with removable dies and a hard stone gingiva.1,2 This cast is essential to the integration of the definitive restoration with the architecture of the gingiva. It is obtained by repositioning a set of dies (trimmed as a root form with antirotation grooves) into the definitive impression, and subsequently pouring a solid base.1,2 This so-called “alveolar cast” (cast base with alveolar sockets) is not a substitute for another important cast, the solid cast, which is obtained from a single pour of the definitive impression, trimmed and mounted in an articulator. The solid cast represents the most accurate reference for intertooth relationships, and is used only during the final stage of laboratory procedures, for evaluation of the occlusion of the restoration. During the initial stage of restoration fabrication, the soft tissue cast (alveolar cast) will be primarily used. The ceramist is guided by the diagnostic waxing from the diagnostic cast. To facilitate this task, a method to accurately transfer the diagnostic waxing onto a set of removable dies for the soft tissue definitive cast is described. Because all sets of dies result from precise duplication of the original single dies, they all feature identical root portions that fit the alveolar stone base. The dies with transferred waxing can therefore be used alternatively or in combination with the original stone dies or refractory dies, using the same alveolar base (Fig. 1).