Fracture resistance of all‐ceramic crowns placed on a preparation with a slice‐formed finishing line

Abstract

The purpose of this study was to determine the fracture resistance of all-ceramic crowns with a core of a zirconia ceramic, using various stabilizing oxides and luted on a preparation with a slice-formed finishing line. Ten cores made of HIPed yttrium-oxide partially stabilized zirconia (HIPed Y-TZP) and five cores of densely-sintered magnesia partially stabilized zirconia (Mg-PSZ) were made. The Mg-PSZ cores and five of the HIPed Y-TZP cores were made with a thickness of 0.2 mm. A further five cores 0.1-mm thick were made of HIPed Y-TZP. All 15 cores were then veneered with a feldspar ceramic and luted onto a stylized steel master die model with a slice-formed finishing line. The specimens were then loaded until fracture occurred. The HIPed Y-TZP specimens with the 0.2 mm core exhibited significantly higher fracture resistance than the Mg-PSZ specimens (P = 0.004) and the HIPed Y-TZP specimens with the 0.1 mm core (P = 0.001). The fracture resistance of the Mg-PSZ specimens was significantly (P = 0.015) higher than that of the HIPed Y-TZP specimens with the 0.1 mm core. The fracture resistance determined was equal or superior to reported values for bite forces and all-ceramic crowns. Thus, it seems likely that the type of restorations evaluated have the potential for successful use on a slice-formed preparation. However, long-term studies are essential in order to assess the performance of this ceramic system in a clinical context.

Finite Element Analysis of the Influence of Geometry and Design of Zirconia Crowns on Stress Distribution

“…Investigators have studied several factors in an attempt to better understand these failures . In the study of restorative materials by in vitro tests, the results with specimens having simplified formats were reported to be constant . When no anatomical specimens are used in laboratory tests, it is possible to have more control over the basic mechanical properties of the materials, but the effects of restoration geometry on stress distribution are excluded .…”

Influence of the supporting die structures on the fracture strength of all-ceramic materials

“…Resin bonding of ceramic restorations to the supporting tooth structure increases the fracture resistance of the restored tooth and the restoration itself [9,17,18]. Many studies have evaluated the fracture strength of allceramic crowns [4,[19][20][21][22][23][24][25][26][27][28][29][30][31] using metal [4,21,23,25], brass [19,26], acrylic resin [20], epoxy resin [24,27], and dentin [22] as supporting die materials. Increasing the elastic modulus of the supporting die material has been suggested as a means to increase the fracture resistance of all-ceramic posterior crowns [11].…”

Farkli Güdük Materyalleri̇, Saklama Ortami Ve Si̇manin Zi̇rkon Alt Yapilarinin Kirilma Di̇renci̇ Üzeri̇nde Etki̇si̇

“…Bu yüzden çalıĢmamız in vitro ortamda gerçek-leĢtirilmiĢtir. 37 Tam seramik kuronlarda kırılma dayanı-mının değerlendirildiği çoğu çalıĢmada güdük materyali olarak metal 21,38,39 , pirinç 40,41 , epoksi rezin 21,38,42,43 ve dentin 21,44 kullanılmıĢtır. Bu çalıĢmada da bu amaçla klinik ortamı taklit edebilmek ve standardizasyonu sağlayabilmek için dentinin elastik modülüne yakın güdük materyali arayıĢına girilmiĢtir.…”