Qing Ping, Huang Shengbin, Gao ShanShan, Qian LinMao, Yu HaiYang
State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China.
Department of Prosthodontics, School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, PR China.
Sci Rep. 2015 Jun 23;5:11568. doi: 10.1038/srep11568.
Radiotherapy is a frequently used treatment for oral cancer. Extensive research has been conducted to detect the mechanical properties of dental hard tissues after irradiation at the macroscale. However, little is known about the influence of irradiation on the tribological properties of enamel at the micro- or nanoscale. Therefore, this study aimed to investigate the effect of gamma irradiation on the wear behaviour of human tooth enamel in relation to prism orientation. Nanoscratch tests, surface profilometer and scanning electron microscope (SEM) analysis were used to evaluate the friction behaviour of enamel slabs before and after treatment with identical irradiation procedures. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were performed to analyse the changes in crystallography and chemical composition induced by irradiation. Surface microhardness (SMH) alteration was also evaluated. The results showed that irradiation resulted in different scratch morphologies, friction coefficients and remnant depth and width at different loads. An inferior nanoscratch resistance was observed independent of prism orientation. Moreover, the variation of wear behaviours was closely related to changes in the crystallography, chemical composition and SMH of the enamel. Together, these measures indicated that irradiation had a direct deleterious effect on the wear behaviour of human tooth enamel.
放射治疗是口腔癌常用的治疗方法。人们已经进行了广泛的研究，以在宏观尺度上检测辐照后牙齿硬组织的力学性能。然而，关于辐照在微观或纳米尺度上对牙釉质摩擦学性能的影响却知之甚少。因此，本研究旨在探讨γ辐照对人牙釉质磨损行为的影响及其与棱柱取向的关系。采用纳米划痕试验、表面轮廓仪和扫描电子显微镜（SEM）分析，评估了相同辐照程序处理前后牙釉质板的摩擦行为。进行了X射线衍射（XRD）和傅里叶变换红外光谱（FTIR）分析，以分析辐照引起的晶体学和化学成分变化。还评估了表面显微硬度（SMH）的改变。结果表明，辐照在不同载荷下导致不同的划痕形态、摩擦系数以及残余深度和宽度。无论棱柱取向如何，均观察到较差的纳米划痕抗性。此外，磨损行为的变化与牙釉质的晶体学、化学成分和SMH的变化密切相关。这些结果共同表明，辐照对人牙釉质的磨损行为有直接的有害影响。
