EFFECT OF PRE-CRYSTALLIZATION ON LITHIUM DISILICATE GLASS-CERAMICS FABRICATED BY DIFFERENT PROCESSES

SiO2-Li2O-K2O-Al2O3-P2O5 based lithium disilicate glass ceramic was prepared and fabricated into dental crowns. The influence of factors such as pre-crystallization temperature and fabrication technique on the phase formation and morphology of the glass ceramic was investigated. Differential thermal analysis (DTA), X-ray diffraction (XRD), scanning and transmission electron microscopies (SEM and TEM) were performed to determine the thermal properties, the phase formation and microstructure of the samples, respectively. The composition of lithium disilicate glass ceramic could be fabricated into dental crowns through the hot-pressing and CAD/CAM techniques. Similarities in phase formation have been revealed on the dental crown samples after fabrication by both methods. The dental crown samples fabricated by the CAD/CAM technique exhibited significantly finer needle-like crystals of lithium disilicate. The pre-cerammed ingots and fabrication technique have no significant change on the phase formation; however, they play important roles in changing the morphology of the samples in this study. (Received January 01, 2016; Accepted April 30, 2016)