Comparison of Two Heat-pressed All-ceramic Crown Systems

Abstract

There is increasing demand for all-ceramic crowns to improve esthetics and avoid the intraoral use of metal. There are several ways to fabricate all-ceramic prostheses. The heat-press method is easily handled, creates less porosity than the conventional powder slurry method, produces consistent quality, and avoids firing shrinkage. Each of the popular brands of heat-press ceramics has its own heat-press furnace. The purposes of this study were to determine whether it was possible to use one heat-press furnace to make different all-ceramic prostheses, and to compare the fit and hardness of two commercial heat-press all-ceramic systems made using the staining technique. Ceramic ingots were analyzed by X-ray diffraction analysis before heat press. Finesse® All-Ceramic and OPC 3G® specimens were both heat-pressed using a porcelain pressing furnace designed for Finesse®. Mesio-occluso-distal inlays were cemented to the metal die with temporary cement. Marginal accuracy was measured using a three-dimensional coordinate measuring machine. Vickers hardness was measured using a microhardness tester. X-ray diffraction analysis of the ceramic ingots showed that the main peak position for Finesse® was leucite (KAlSi2O6) and for OPC 3G® was lithium disilicate (Li2Si2O5). The marginal gap for Finesse® was statistically lower than that for OPC 3G® (62.5 ± 15.5 vs 99.4 ± 11.6 mm; p 0.05). The marginal gaps for Finesse® and OPC 3G® were clinically acceptable. Therefore, it is possible to use one heat-press furnace to cast different all-ceramic systems.

Keywords

• full ceramics
• heat-pressed
• marginal discrepancy