Conservative indirect restorations for posterior teeth. Cast versus bonded ceramic.
The practitioner today has a number of alternative restorative modalities from which to chose when faced with the necessity of restoring posterior teeth. The primary options with extensively broken down posterior teeth are cast gold and bonded ceramic inlays, onlays, and partial veneer restorations. The dentist and informed patient should make the choice of which modality is appropriate based on a number of criteria. Certainly, based on the criteria of basic physical properties, potential for marginal integrity and stability of that integrity, cast gold is the material of choice. In terms of conservation of tooth structure and systemic biocompatibility, both restoration types are excellent. With regard to effects on long-term pulpal health, much remains unknown with many of the materials used with bonded restorations at the present time. Conservative cast gold restorations have proved to be very successful in this regard over the long term. The potential for tooth strengthening with bonded restorations is certainly an exciting, but as yet, unproven, clinical reality. Thus, until those clinical data are available, the most predictable means of restoration of extensively broken down posterior teeth is with partial-coverage cast gold, protecting cusps at risk as required (Fig. 9). As mentioned previously, cast gold inlays are also a very conservative and predictable restoration (Fig. 10). Both cast gold and bonded ceramic restorations are technically demanding, but the details required to produce excellent gold castings are well defined, and can be learned readily. Much remains to be learned regarding the materials and the techniques used to fabricate bonded ceramic restorations. Priority issues would seem to be reaching a consensus regarding the details of tooth preparation and the development of improved luting resins with improved wear resistance. Simplified techniques to improve the quality of the fit of these types of restoration also are of paramount importance. The requirement for an esthetic, or, more properly, use of a tooth-colored restoration in a posterior tooth, should be evaluated carefully for each individual restoration. Often it is possible to restore a tooth with cast gold with minimal or no display of metal. The patient will then receive the long-term benefit of cast gold and not compromise on esthetics. It is our obligation as diagnosticians to educate our patients so that they are in a position to choose, when indicated, this most cost effective of restorative options.