Preliminary Experimental Study On Dental Porcelain Strengthened And Toungened By Zirconia

It is generally accepted that ceramic restorations exhibit excellent aesthetic characteristics and biocompatibility, however, the mechanical shortcomings of such materials including their inherent brittleness and potential to abrade the opposing dentition limit the fabrication and application of all-ceramic restorations. The major course of ceramic restoration failure in clinic is brittle fracture. Even though Porcelain- fused-to Metal (PFM) could supply enough strength, it has the danger of potential metal erosion and the color of metal may shine through the slight edge at the cervical, furthermore, the problem of bond strength between metal and ceramics still trouble clinics. Recent developments have attempted to overcome such disadvantages by either the use of increasingly complex technology or by the simplification of existing techniques and/or materials. In this study, Zirconia was used as an additive to strengthen and toughen the ceramics. To determine the composition and the synthesis routine of a dental Glass-ceramics strengthened and toughened by Zirconia. By means of DTA, XRD, the crystallizing procedure and structure of crystallite when sintered under different conditions were investigated. The intenerate temperature of the composite increased as more YTZP appeared. It was concluded that I 5wt%YTZP composite would be more suitable for clinical application. Composite powder was made from raw materials of different size and purity, according to different formula and synthesizing methods including co-precipitation method, precipitate-wrapping method and mix method. The ZTA ceramics were prepared by means of dry-pressing technique and the electrical cannel kiln sintering. Function of composite thods is compared powder made with different preparing me synthetically. Composite powder with a large proportion t-Zr02 was made with precipitate-wrapping method. In general, the precipitate- wrapping methods were better than the Co-precipitation methods and the mixing methods. The purity and size of raw materials had great effects on the properties of ZTA ceramics. Additives could decrease the ZTA ceramics sintering temperature in different degree and had an effect on the properties of ZTA ceramics.