Wertz Markus, Schmidt Michael Benno, Hoelzig Hieronymus, Wagner Maximilian, Abel Bernd, Kloess Gert, Hahnel Sebastian, Koenig Andreas
Department of Prosthodontics and Material Sciences, Leipzig University, 04103 Leipzig, Germany.
Department of Prosthetic Dentistry, University Hospital of Regensburg, 93053 Regensburg, Germany.
Materials (Basel). 2022 Jun 24;15(13):4471. doi: 10.3390/ma15134471.
In the study the influence of different dental technical tools on the surface temperature and phase composition of fixed dental prostheses (FDPs) made of yttria-partially stabilized zirconia polycrystals (3Y-/4Y-/5Y-PSZ) was investigated. FDPs were fabricated by using computer-aided manufacturing (CAM). The FDPs were treated with a contra-angle handpiece equipped with different burs and polishers. The resulting surface temperatures were measured with a thermographic camera, and the resulting phase transformations were investigated by X-ray diffraction and quantified by Rietveld refinement. Processing with burs resulted in no phase transformation, but a preferred orientation shift. Using coarse polisher induced a phase transformation to the rhombohedral phase, while fine polishers produced no relevant phase transformations and no preferred orientation shift. Compared to the monoclinic phase (ca. 9% theoretical volume increase), which is associated with low-temperature degradation (LTD), the rhombohedral phase is much more voluminous (ca. 15% theoretical volume increase) and distorted and, therefore, has a greater degradation potential.
在该研究中，研究了不同牙科技术工具对由氧化钇部分稳定的多晶氧化锆（3Y-/4Y-/5Y-PSZ）制成的固定义齿（FDP）表面温度和相组成的影响。FDP通过计算机辅助制造（CAM）制作。使用配备不同车针和抛光器的弯手机对FDP进行处理。用热成像相机测量所得表面温度，并通过X射线衍射研究所得相变，并用Rietveld精修进行量化。用车针处理未导致相变，但产生了择优取向偏移。使用粗抛光器会诱导向菱面体相的相变，而细抛光器未产生相关相变且没有择优取向偏移。与与低温降解（LTD）相关的单斜相（理论体积增加约9%）相比，菱面体相的体积大得多（理论体积增加约15%）且发生畸变，因此具有更大的降解潜力。
