The first particle used for filling purposes in dental ceramics is a crystalline mineral called potassium leucite
, which is in the form of potassium alumina silicate (6).
The increase in solubility of leucite
crystals may be another explanation of this undesired property ot the ceramic core.
Hinds, "Ion-exchange in crystals of analcite and leucite
," Journal of the Chemical Society, pp.
 Furthermore, repeated firings may also produce changes in micro-crack density and partial decoupling of the leucite
from the surrounding glass matrix, resulting in a lowering of the bulk thermal expansion of the porcelain.
Typical minerals found in lamproite rocks include forsterite, leucite
, phlogopite, and iron-rich sanidine.
The new wet grinding function of Zenotec select hybrid accommodates the milling requirements of the lithium disilicate glass-ceramic IPS e.max CAD and the leucite
glass- ceramic IPS Empress CAD.
Standards included diopside (Ca, Mg), fluorite (F), jadeite (Na, Al), leucite
(K), magnetite (Fe), quartz (Si), RbCl (Rb), rhodonite (Mn), rutile (Ti), spinel (Cr) and tugtupite (Cl).
Three commercially available IRCs, which were chosen in accordance with their different types of filler particles; two microhybrids, Gradia (GRD; GC Europe, Leuven, Belgium) and Tescera (TES; Bisco Inc., Schaumburg IL USA), and one hybrid, Estenia C&B (EST; Kuraray Medical Co, Tokyo, Japan); two ceramic materials: a glass ceramic, Empress 2 layering (E2; Ivoclar Vivadent, Schaan, Liechtenstein), and a leucite
reinforced glass ceramic, Empress Esthetic (EE; Ivoclar Vivadent, Schaan, Liechtenstein); and two PPPs: Detartrine (DT; Septodont GmbH, Niederkassel Germany) and Topex (TP; Sultan Healthcare, Hackensack NJ, USA), were used in the study.
Exports of Felspar, Nepheline, Nepheline Syenite, Leucite
and Fluorspar has grew month on month basis by 348.35%.
The intrusive analogues (theralites, essexitic gabbros, ijolites and essexites) show a holocrystalline inequigranular texture, with diopsidic pyroxene ([Wo.sub.44-51][Fs.sub.8-17]), olivine ([Fo.sub.75-82] to [Fo.sub.44-66]), mica (Ti-phlogopite to Ti-biotite), Timagnetite, alkali feldspar, and nepheline ([Ne.sub.64-80][Ks.sub.20-36]) [+ or -] leucite
[+ or -] amphibole.
The PFM veneer was Ceramco 3 (Dentsply Prosthetics, York, PA) (1), a feldspathic veneering porcelain containing about 0.30 volume fraction leucite
. The veneer for the zirconia, Ceramco PFZ (Dentsply Prosthetics, York, PA), was designed to be used with a 3 mole % yttria stabilized zirconia (Cercon) made by the same manufacturer.