Influence of yttria content and surface treatment on the strength of translucent zirconia materials

Abstract

Zirconia first gained attention as an engineering ceramic in the 1970s and began to be used in prosthodontics in the late 1990s. [1][2][3] Zirconia exhibits polymorphism, existing in cubic, tetragonal, and monoclinic forms. A martensitic phase transformation from tetragonal to monoclinic (t/m) zirconia forms is accompanied by a 4% increase in volume. However, a small amount of controlled expansion can decrease crack propagation, thereby making a material tougher through a process called transformation toughening. 4,5 The addition of stabilizing oxides, typically yttria (Y 2 O 3 ), can create tough multiphase partially or fully stabilized zirconia materials. 1,2 Zirconias that are capable of undergoing transformation toughening do not exhibit a proportional relationship between toughness and strength. 5,6 A wide variety of zirconia formulations are possible, each having their own distinctive physical properties. 6,7

Las PROPIEDADES ÓPTICAS Y MECÁNICAS DEL ZIRCONIO TRANSLÚCIDO COMO MATERIAL RESTAURADOR ÓPTIMO EN PRÓTESIS FIJA UNA REVISIÓN DE LA LITERATURA

“…Este endurecimiento le proporciona su alta tenacidad a la fractura; sin embargo, la desventaja que presenta es la opacidad, debido a la presencia de alúmina. Este material se le agregó para ayudar a prevenir la formación de poros y estabilizar el zirconio tetragonal 4 , 6 , 16 .…”

“…En la primera generación, las zirconias utilizadas en odontología, en su mayoría, contenían 3 mol% de itria (3Y) y 0,25% de peso de alúmina, material conocido como zirconio opaco. Este proporciona una resistencia significativamente mayor y está indicado para restauraciones posteriores de la boca 4 , 5 . En la segunda generación, se presentó una reducción de la concentración de alúmina y se realizó la sinterización a una alta temperatura del 3 Y, para lograr menor opacidad; sin embargo, este material carece de translucidez.…”

Effect of Repeated Firings and Thickness on Optical Properties of Variable Preshaded and Shaded Novel Translucent Zirconia Blocks

“…Translucency of zirconia is mainly dependent on light scattering and thickness [2]. Also, yttria content, phase composition, grain size, number of firings, sintering temperature, and coloring method are crucial factors that affect the translucency and color of zirconia [3][4][5]. Translucency was determined by spectrophotometers which measure the spectral reflectance of an object one wavelength at a time and converts it into numerical form [6].…”

Retentive Strength of CAD/CAM-Fabricated All-Ceramic Crowns Luted on Titanium Implant Abutments Using Different Ceramic Materials and Luting Agents: An In Vitro Study

“…Furthermore, a study showed that the stability of the crown-abutment connection in implants can be dependent on the “ferrule effect”, analogous to natural teeth, and consequently increases in the presence of ferrulization [ 9 ]. The fixation data published is as follows: analyzing the effect of contamination of the bond surface [ 10 , 11 , 12 ], the cement type and abutment height [ 13 ], abutment platform configuration [ 14 ], airborne-particle abrasion by using alumina [ 15 ] or silanisation and laser pretreatment [ 16 ] on retention force of the restoration. In addition, it is possibly to be expected that the adhesive interface behavior between the implant surface, the luting agent, and the bond surface of the ceramic restoration could be meaningful for the stabilization of the ceramic restoration.…”