Institute of Stomatology, School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, PR China; Department of Prosthodontics, School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, PR China.
Institute of Stomatology, School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, PR China; Department of Endodontics, School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, PR China.
J Mech Behav Biomed Mater. 2021 Aug;120:104585. doi: 10.1016/j.jmbbm.2021.104585. Epub 2021 May 13.
The aim of this study was to investigate the wear behavior of Dentinogenesis imperfecta type II (DGI-II) dentin and elucidate the correlation between its tribological properties and components.
The mid-coronal dentin of normal and DGI-II teeth were divided into two groups: perpendicular and parallel to the dentin tubules. The microstructure of dentin was detected using atomic force microscopy (AFM). The wear behavior of dentin was evaluated by nanoscratch tests and scanning electron microscopy (SEM). Meanwhile, changes in molecular groups and chemical composition were analyzed by Raman and Energy-Dispersive X-ray (EDX) tests, respectively. Nanohardness was also evaluated.
AFM images of DGI-II dentin illustrated a decrease in the number of tubules and the tubule diameter. Nanoscratch test showed a higher friction coefficient and a greater depth-of-scratch in DGI-II dentin. The wear resistance of DGI-II dentin was reduced independent of tubule orientation. EDX results indicated that DGI-II dentin mineral content decreased and Raman spectra results showed DGI-II dentin had a decreased collagen matrix structure stability coupled with hypomineralization. Furthermore, a significant reduction in nanohardness and elastic modulus of DGI-II dentin was observed. Regression analysis revealed a close correlation between dentin components and inferior wear resistance.
All results indicated the wear behavior of DGI-II dentin was significantly deteriorated, presumably caused by the disorder in microstructures and the reduction of chemical composition.
本研究旨在探讨 II 型牙本质生成不全（DGI-II）牙本质的磨损行为，并阐明其摩擦学性能与成分之间的相关性。
将正常和 DGI-II 牙齿的中部牙本质分为两组：与牙本质小管垂直和平行。采用原子力显微镜（AFM）检测牙本质的微观结构。通过纳米划痕试验和扫描电子显微镜（SEM）评估牙本质的磨损行为。同时，通过拉曼和能谱（EDX）测试分别分析分子基团和化学成分的变化。还评估了纳米硬度。
DGI-II 牙本质的 AFM 图像显示小管数量和直径减少。纳米划痕试验表明 DGI-II 牙本质的摩擦系数较高，划痕深度较大。DGI-II 牙本质的耐磨损性降低，与小管取向无关。EDX 结果表明 DGI-II 牙本质的矿物质含量减少，拉曼光谱结果表明 DGI-II 牙本质的胶原基质结构稳定性降低，伴矿化不足。此外，DGI-II 牙本质的纳米硬度和弹性模量显著降低。回归分析表明牙本质成分与耐磨损性降低密切相关。
所有结果表明，DGI-II 牙本质的磨损行为明显恶化，可能是由于微结构紊乱和化学成分减少所致。
