Objective

The aims of this study were: 1) to evaluate the effect of sintering temperature on microstructure, density and flexural strength of a 3Y-TZP/TiO₂ composite containing 12.5 wt% of TiO₂ compared to 3Y-TZP specimens (control); 2) to compare 3Y-TZP with the experimental 3Y-TZP/TiO₂ composite, both sintered at 1400 °C, with respect to the following parameters: optical properties, characteristic strength, Weibull modulus, fatigue behavior, induction of osteoblasts proliferation and differentiation (mineralization nodules formation).

Methods

The 3Y-TZP and 3Y-TZP/TiO₂ powders were uniaxially pressed and sintered at 1200 °C, 1300 °C, 1400 °C or 1500 °C for one hour in a furnace. The microstructural analysis consisted of X-ray diffraction and scanning electron microscopy. The density was measured by the Archimedes' principle and the flexural strength was obtained by the biaxial flexure test. The optical properties were measured using a spectrophotometer operating in the visible light wavelength range. The step-stress accelerated life testing was performed by the pneumatic mechanical cycler and the biological behavior achieved by using osteoblast-like cells (Osteo-1 cell line).

Results

Tetragonal zirconia was identified in all groups and cubic zirconia was identified only at 3Y-TZP group. The addition of TiO₂ decreased the values of density and flexural strength of the composite 3Y-TZP/TiO₂ in relation to 3Y-TZP regardless of the sintering temperature. The color difference between the two materials was not significant regarding L*a*b* parameters. The composite showed higher probability of failure, and induced higher proliferation and differentiation than control.

Significance

The composite developed have good aesthetic and biologics properties. However, its microstructure and mechanical properties need to be improved for future dental implant applications.

中文翻译：

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二氧化钛的添加和烧结温度对Y-TZP / TiO2复合材料的微观结构，光学，机械和生物学性能的影响。

目的

本研究的目的是：1），以评估对微结构，密度和3Y-TZP /二氧化钛的挠曲强度烧结温度的效果₂复合含有TiO 12.5％（重量）₂相比，3Y-TZP试样（对照）; 2）将3Y-TZP与在1400°C烧结的实验3Y-TZP / TiO ₂复合材料进行比较，涉及以下参数：光学性能，特征强度，威布尔模量，疲劳行为，诱导成骨细胞增殖和分化（矿化结节的形成）。

方法

将3Y-TZP和3Y-TZP / TiO ₂粉末单轴压制并在炉中在1200℃，1300℃，1400℃或1500℃下烧结1小时。显微组织由X射线衍射和扫描电子显微镜组成。通过阿基米德原理测量密度，并通过双轴弯曲试验获得弯曲强度。使用在可见光波长范围内操作的分光光度计测量光学性质。通过气动机械循环仪进行阶跃应力加速寿命测试，并通过使用成骨细胞样细胞（Osteo-1细胞系）实现生物学行为。

结果

在所有组中均发现了四方氧化锆，仅在3Y-TZP组中发现了立方氧化锆。相对于3Y-TZP ，TiO _2的添加降低了复合3Y-TZP / TiO ₂的密度和抗弯强度的值，而与烧结温度无关。对于L * a * b *参数，两种材料之间的色差不明显。复合材料显示更高的失败概率，并诱导更高的增殖和分化比对照。

意义

开发的复合材料具有良好的美学和生物特性。然而，其微结构和机械性能需要改进以用于将来的牙植入物应用。