Optical properties of translucent zirconia: A review of the literature

Abstract

Translucent monolithic zirconia is the newest option of zirconia-based ceramics, which aimed to substitute the opaque classic yttria-stabilized tetragonal zirconia polycrystal (Y-TZPs) in more demanding esthetic cases. The aim of this review was to assess the available literature regarding the optical, chemical and mechanical properties of translucent zirconia ceramics. This systematic review was developed according to the PRISMA (Preferred Reporting Items for Systematic Review and Meta-analysis) guidelines. An electronic literature search was undertaken through Medline (National Library of Medicine) via PubMed to identify relevant articles, published in the interval 2010-2018. The search was limited to the English language publications, in vitro studies of color and microstructure of translucent zirconia material. Yttria-stabilized tetragonal zirconia polycrystals (Y-TZPs) has excellent mechanical properties, but its intense white color and high opacity represent an esthetic limit. Cubic zirconia represents a new generation of dental ceramics with molecular structure and physical properties different from the conventional zirconia. Dental manufacturers created new formulations of this restorative material, introducing new cubic varieties of zirconia with improved optical properties. Translucent monolithic zirconia provides a new restorative option that combines strength with improved esthetics, due to its increased translucency. Translucent zirconia is indicated for anterior and posterior restorations but should be used carefully for discolored teeth, because the background color can affect the final esthetic appearance of the restoration.

Gelcast Zirconia Ceramics With High Strength and Simultaneously High Translucency for Dental Applications

“…Three methods for improving translucency have been reported [17][18][19]. The principle of all these methods consists in reducing the backscattering in the ceramics because other factors are difficult to control.…”

Microhardness of resin cements after light activation through various translucencies of monolithic zirconia

“…Since the new generation of monolithic zirconia provides high translucency similar to lithium disilicate ceramic, 24 more anterior applications, such as crowns, bridges, and veneers, become possible. 25 26 It would be advantageous for light polymerization of resin cement below the restorations, enhancing the use of light-cured resin cements with the advantages of easier excess cement removal, extended working time, and good color stability, compared to dual-cured cements. 27 The degree of light transmission through the translucent monolithic zirconia should be investigated in order to assess the degree of conversion of light- compared to dual-cured resin cements, with respect to the different levels of translucency available.…”

Di̇ş Heki̇mli̇ği̇nde Yeni̇ Geli̇şti̇ri̇len Yüksek Translüsent Monoli̇ti̇k Parsi̇yel Stabi̇li̇ze Zi̇rkonya Si̇stemleri̇ni̇n Opti̇k Ve Mekani̇k Özelli̇kleri̇ni̇n Değerlendi̇ri̇lmesi̇: Derleme

“…1,170 °C'lik bir sıcaklıkta, zirkonyumun oda sıcaklığında mevcut olduğu monoklinik faza dönüşüm nihayet gerçekleşir. 6,7 Dental uygulamalar için parsiyel stabilize zirkonya (PSZ), tetragonal zirkonya polikristal (TZP), zirkonya sertleştirilmiş alümina (ZTA) ve tamamen kübik stabilize zirkonya (CSZ) dahil olmak üzere çeşitli zirkonya tipleri mevcuttur. 7 Geleneksel zirkonyanın en sık kullanılan hali, %3 mol itriya (3Y-TZP) ile stabilize edilmiş ve %0.25 alümina ile güçlendirilmiş yüksek dayanıklı tetragonal kristal fazdır.…”

“…7 Geleneksel zirkonyanın en sık kullanılan hali, %3 mol itriya (3Y-TZP) ile stabilize edilmiş ve %0.25 alümina ile güçlendirilmiş yüksek dayanıklı tetragonal kristal fazdır. 6,8 Geleneksel zirkonya mükemmel mekanik özelliklere sahiptir, ancak estetik özellikleri zayıf ve opaktır. Günümüzde Y-TZP zirkonya seramikleri, dental kronların ve özellikle ön bölge ve posterior bölgede uzun köprü restorasyonlarının yapımında kullanılmaktadır.…”

“…Aynı zamanda ısıtma yöntemleri, sinterleme için kullanılan sıcaklık ve atmosfer koşulları, ışık dağılımını etkileyen faktörler de etkilidir. 6 Translüsent monolitik zirkonya restorasyonları üretmek için kullanılan yöntemlerden biri, tetragonal fazda tanecik boyutunu arttırmak olmuştur. 11,43,48 Başka bir yöntem, tanecik boyutunu görünür ışığın dalga boyundan (400-700 nm) daha küçük olan 100 nm'nin altına indirmektir.…”