氧化锆和一种高贵金属合金与它们相应瓷材结合后的抗弯强度和抗剪强度。

Flexural and shear strengths of ZrO2 and a high-noble alloy bonded to their corresponding porcelains.

作者信息

Ashkanani Hamid M, Raigrodski Ariel J, Flinn Brian D, Heindl Harald, Mancl Lloyd A

机构信息

Graduate Prosthodontics, Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA 98195-7456, USA.

出版信息

J Prosthet Dent. 2008 Oct;100(4):274-84. doi: 10.1016/S0022-3913(08)60206-1.

DOI:10.1016/S0022-3913(08)60206-1

PMID:18922256

Abstract

STATEMENT OF PROBLEM

Flexural and shear strength between ZrO(2) cores and veneering porcelains require investigation to facilitate clinical use.

PURPOSE

The purpose of this study was to assess the strength of ZrO(2) and a high-noble alloy with corresponding porcelains.

MATERIAL AND METHODS

Forty rectanglar (12 x 10 x 3 mm) and 20 cylindrical (5 x 5 mm) specimens of ZrO(2) (Lava) and high-noble alloy (Olympia) were fabricated for 4-point flexural testing and shear testing. IPS d.SIGN veneering porcelain for high-noble alloy and Lava Ceram, 2 mm thick, were fired, joining the 2 corresponding rectangles of high-noble alloy and ZrO(2) to create flexural test specimens. The same types of veneering porcelains, 3 mm in thickness, were fired on 1 side of the corresponding high-noble alloy and ZrO(2) cylinders to produce shear specimens. The flexural and shear specimens were divided into 4 groups (n=10); metal ceramic and ZrO(2) with and without thermal cycling. Thermal cycling was performed at 5 degrees C and 55 degrees C for 5000 cycles with a 20-second dwell time. Flexural and shear tests were performed using a universal testing machine. Fractures were characterized using a stereomicroscope and SEM. Data were analyzed with a 1-way ANOVA and Tukey HSD post hoc test (alpha=.05).

RESULTS

The ANOVA revealed a significant difference among flexural groups (P=.008) and among shear groups (P<.001). In flexure, the Tukey HSD post hoc test revealed a significant difference (P=.005) between metal ceramic thermal cycled and ZrO(2) thermal cycled groups, with a higher value of 91.01 (22.33) MPa for the metal ceramic group. In shear, the Tukey HSD post hoc test revealed a significant difference between metal ceramic and ZrO(2) groups, with a higher value of 82.00 (22.49) MPa for the metal ceramic group. Thermal cycling did not have a significant effect on flexure or shear strength. ZrO(2) specimens failed cohesively within the veneering porcelain.

CONCLUSIONS

There were no significant differences among the groups in flexure, except between thermal cycled metal ceramic and ZrO(2) groups. There was a significant difference between the metal ceramic and ZrO(2) groups in shear. Thermal cycling did not have a clear effect among different groups in both tests.

摘要

问题陈述

氧化锆（ZrO₂）核与饰面瓷之间的弯曲强度和剪切强度需要进行研究，以促进临床应用。

目的

本研究的目的是评估氧化锆（ZrO₂）和高贵金属合金与相应瓷材的强度。

材料与方法

制备40个长方形（12×10×3mm）和20个圆柱形（5×5mm）的氧化锆（Lava）和高贵金属合金（Olympia）试件，用于四点弯曲试验和剪切试验。将用于高贵金属合金的IPS d.SIGN饰面瓷和2mm厚的Lava Ceram瓷材烧制，将高贵金属合金和氧化锆（ZrO₂）的2个相应长方形连接起来，制成弯曲试验试件。将相同类型、厚度为3mm的饰面瓷材烧制在相应高贵金属合金和氧化锆（ZrO₂）圆柱体的一侧，制成剪切试件。将弯曲和剪切试件分为4组（n = 10）；分别为有热循环和无热循环的金属烤瓷组以及氧化锆（ZrO₂）组。热循环在5℃和55℃下进行5000次循环，保压时间为20秒。使用万能试验机进行弯曲和剪切试验。使用体视显微镜和扫描电子显微镜对断裂情况进行表征。数据采用单因素方差分析和Tukey HSD事后检验进行分析（α = 0.05）。

结果

方差分析显示弯曲组之间存在显著差异（P = 0.008），剪切组之间也存在显著差异（P < 0.001）。在弯曲试验中，Tukey HSD事后检验显示金属烤瓷热循环组和氧化锆（ZrO₂）热循环组之间存在显著差异（P = 0.005），金属烤瓷组的值更高，为91.01（22.33）MPa。在剪切试验中，Tukey HSD事后检验显示金属烤瓷组和氧化锆（ZrO₂）组之间存在显著差异，金属烤瓷组的值更高，为82.00（22.49）MPa。热循环对弯曲强度或剪切强度没有显著影响。氧化锆（ZrO₂）试件在饰面瓷内部发生内聚性破坏。