Although they are called rare elements, they are not rare at all, as they are more plentiful and abundant than silver, gold, and platinum, and the least plentiful elements of the REE are leucite
is created in dental porcelain by increasing the potassium oxide (chemical formula K2O) content of the aluminosilicate glass.
Silicate minerals, such as K-feldspar, leucite
, nepheline, kalsilite, muscovite, biotite and phlogopite, can readily provide K to plants.
evaluated the influence of a restorative material type on the biomechanical behavior of endocrown restorations and concluded that Leucite
presents a better stress distribution and it can be a promising alternative to lithium disilicate for the manufacture of endocrown restorations .
Despite its superior physical properties, the leucite
reinforced ceramic core (Group C) showed 2 to 4 times more wear over 32 years of CST when compared with other test groups.
Porcelain which is used for making dental prosthesis comprises glass matrix and leucite
crystalline phase, the later consisting of various elements particularly Si (57-66%), Ba2+ (15-25%), Al3+ (7-15%), Na+(7-12%), K+(7-15%) and lithium ion (Li+)(0.5-3%).
According to the report by Barrer and Hinds [34, 35], analcime (NaAl[Si.sub.2][O.sub.6]) shows limited solid solubility of leucite
(KAl[Si.sub.2][O.sub.6]) at both higher temperatures and very low temperatures under hydrothermal conditions.
Abutment z Zirconia t Titanium g Gold alloy: cast-to abutment (Astra Tech): Au 60%, Pt 19%, pd 20%, Ir 1%, or gold-hue titanium Veneering IPS Empress 2: apatite glass-ceramic (Ivoclar Vivadent) IPS d.SIGN: fluorapatite leucite
glass-ceramic (Ivoclar Vivadent, Schaan, Liechtenstein) Crown coping z Procera Zirconia: yttria-stabilized tetragonal zirconia polycrystal, Y-TZP (Nobel Biocare[TM], Gothenburg, Sweden) m ORION WX: gold alloy, AU 52.0%, Pd 38.0%, In 8.2%, Ga 1.6%, and Ag and Re < 1% (Elephant Dental BV, Hoorn, Netherlands) Table 2: Color difference ([DELTA]E) of the implant crown and peri-implant mucosa compared to neighboring tooth and gingival (M [+ or -] SE and p values) based on different restorative material combinations.
On the other hand Glass based ceramics like Leucite
reinforced glass ceramic has gained popularity among dentists for the past 20 years due to its excellent esthetics.17 The introduction of Lithium disilicate glass ceramics lead to further advancement by the development to IPS E.
This pressed glass- ceramic has an improved flexural strength and fracture toughness as compared to others (leucite
reinforced ceramics) and demonstrates abrasion resistance, chemical durability and optical properties well within the dental standards.1