Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, School of Dentistry, University of California at Los Angeles, USA.
Int J Oral Maxillofac Implants. 2009 Sep-Oct;24(5):831-41.
This study evaluated the biomechanical properties of periosteum-derived mineralized culture on different surface topographies of titanium.
Titanium surfaces modified by machining or by acid etching were analyzed using scanning electron microscopy (SEM). Rat mandibular periosteum-derived cells were cultured on either of the titanium surfaces. Cell proliferation was evaluated by cell counts, and gene expression was analyzed using a reverse-transcriptase polymerase chain reaction. Alkaline phosphatase (ALP) stain assay was employed to evaluate osteoblastic activity. Matrix mineralization was examined via von Kossa stain assay, total calcium deposition, and SEM. The hardness and elastic modulus of mineralized cultures were measured using a nano-indenter.
The machined surface demonstrated a flat topographic configuration, while the acid-etched surface revealed a uniform micron-scale roughness. Both cell density and ALP activity were significantly higher on the machined surface than on the acid-etched surface. The expression of bone-related genes was up-regulated or enhanced on the acid-etched surface compared to the machined surface. Von Kossa stain showed significantly greater positive areas for the machined surface compared to the acid-etched surface, while total calcium deposition was statistically similar. Mineralized culture on the acid-etched surface was characterized by denser calcium deposition, more mature collagen deposition on the superficial layer, and larger and denser globular matrices inside the matrix than the culture on the machined surface. The mineralized matrix on the acid-etched surface was two times harder than on the machined surface, whereas the elastic modulus was comparable between the two surfaces.
The design of this study can be used as a model to evaluate the effect of implant surface topography on the biomechanical properties of periosteum-derived mineralized culture. The results suggest that mandibular periosteal cells respond to different titanium surface topographies differently enough to produce mineralized matrices with different biomechanical qualities.
本研究评估了在钛的不同表面形貌上，骨膜衍生矿化培养的生物力学特性。
通过扫描电子显微镜（SEM）分析经机械加工或酸蚀处理的钛表面。将大鼠下颌骨骨膜衍生细胞培养在钛表面中的任一种上。通过细胞计数评估细胞增殖，并通过逆转录聚合酶链反应分析基因表达。采用碱性磷酸酶（ALP）染色法评估成骨细胞活性。通过 Von Kossa 染色法、总钙沉积和 SEM 检测基质矿化。采用纳米压痕仪测量矿化培养物的硬度和弹性模量。
机械加工表面呈现出平整的形貌，而酸蚀表面呈现出均匀的微米级粗糙度。细胞密度和 ALP 活性在机械加工表面均显著高于酸蚀表面。与机械加工表面相比，骨相关基因在酸蚀表面的表达上调或增强。Von Kossa 染色显示机械加工表面的阳性区域明显大于酸蚀表面，而总钙沉积则无统计学差异。酸蚀表面矿化培养物的特征是在表面层具有更密集的钙沉积、更成熟的胶原沉积，以及在基质内部具有更大且更密集的球状基质，而机械加工表面的矿化培养物则相反。酸蚀表面矿化基质的硬度是机械加工表面的两倍，而弹性模量在两种表面之间相当。
本研究的设计可作为一种模型，用于评估种植体表面形貌对骨膜衍生矿化培养物生物力学特性的影响。结果表明，下颌骨骨膜细胞对不同钛表面形貌的反应足以产生具有不同生物力学特性的矿化基质。
