Ţălu Ştefan, Bramowicz Miroslaw, Kulesza Slawomir, Lainović Tijana, Vilotić Marko, Blažić Larisa
Faculty of Mechanical Engineering, Department of AET, Discipline of Descriptive Geometry and Engineering Graphics, Technical University of Cluj-Napoca, Cluj, Romania.
Faculty of Technical Sciences, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland.
J Microsc. 2016 Nov;264(2):198-206. doi: 10.1111/jmi.12432. Epub 2016 Jun 17.
The aim of this study was to analyse the influence of the artificial saliva on a three-dimensional (3-D) surface texture of contemporary dental composites. The representatives of four composites types were tested: nanofilled (Filtek Ultimate Body, FUB), nanohybrid (Filtek Z550, FZ550), microfilled (Gradia Direct, GD) and microhybrid (Filtek Z250, FZ250). The specimens were polymerised and polished by the multistep protocol (SuperSnap, Shofu). Their surface was examined, before and after 3 weeks' exposure to artificial saliva storage. The surface texture was analysed using the atomic force microscope (AFM). The obtained images were processed to calculate the areal autocorrelation function (AACF), anisotropy ratio S (texture aspect ratio), and structure function (SF). The log-log plots of SF were used to calculate fractal properties, such as fractal dimension D, and pseudo-topothesy K. The analysis showed changes in surface anisotropy ratio S values, which became higher, whereas the S roughness (root-mean-square) reduced after the artificial saliva storage. All the samples exhibited bifractal structure before the saliva treatment, but only half of them remained bifractal afterwards (GD, FZ250), whereas the other half turned into a monofractal (FUB, FZ550). The cube-count fractal dimension D was found to be material- and treatment-insensitive.
本研究的目的是分析人工唾液对当代牙科复合材料三维（3-D）表面纹理的影响。测试了四种复合材料类型的代表：纳米填充（Filtek Ultimate Body，FUB）、纳米混合（Filtek Z550，FZ550）、微填充（Gradia Direct，GD）和微混合（Filtek Z250，FZ250）。通过多步骤方案（SuperSnap，松风）对标本进行聚合和抛光。在暴露于人工唾液储存3周之前和之后检查其表面。使用原子力显微镜（AFM）分析表面纹理。对获得的图像进行处理，以计算面积自相关函数（AACF）、各向异性比S（纹理纵横比）和结构函数（SF）。SF的对数-对数图用于计算分形特性，如分形维数D和伪拓扑性K。分析表明，表面各向异性比S值发生了变化，变得更高，而人工唾液储存后S粗糙度（均方根）降低。所有样品在唾液处理前均表现出双分形结构，但之后只有一半保持双分形（GD，FZ250），而另一半变成了单分形（FUB，FZ550）。发现立方体计数分形维数D对材料和处理不敏感。
