Farklı Kalınlıklardaki CAD/CAM Zirkonya, Hibrit Seramik ve Rezin Nano-Seramik Onleylerin Kırılma Dayanıklılıklarının In-Vitro Olarak Karşılaştırılması

Abstract

Zirconia

has been used in esthetic cases often. Because of its brittleness new materials are

developed like hybrid ceramic and resin nano ceramic. The aim of this study was to

assess and compare the fracture strength of CAD/CAM zirconia, hybrid ceramic

(Vita Enamic) and resin nano-ceramic (3M ESPE Lava Ultimate ) onlays with different

thickness. Ninety premolars were inserted in acrylic resin patterns, embedding the

root up to 3mm below the cement-enamel junction. A standardized tooth

preparation was applied to all specimens and standardized onlays from the Cerec

database was generated with the Cerec 4 CAD/CAM system. Ninety restorations

were divided into 3 groups as follows: 30 resin nano-ceramic onlays, 30 hybrid

ceramic onlays and 30 Zirconia onlays. Each subgroups (n=10) had 0.5, 1.0 and 1.5

mm thickness. After cementation of restorations, static load was applied to all

specimens. The load at failure was recorded. The results were analyzed by one-way

ANOVA and Tukey tests and P< 0.05 was accepted as significant. For the 0,5 mm

group, the fracture load of Vita Enamic was 1655 N which was significantly higher

than others and zirconia onlays had the lowest fracture load with 825 N. For the 1

mm group there was no significant difference between the materials. For 1.5 mm

group zirconia onlays had the highest fracture load with 2133N while Lava Ultimate

was the lowest one which was 1228N. Zirconia onlays showed, increased fracture

load with increased the restoration thickness. All of the onlays failed above the bite

forces. 0,5 mm zirconia onlays must be used carefully in clinical cases.