低温氩氧等离子体活化表面对种植体骨结合的影响及其机制研究

Implant denture has become one of the conventional repairment methods for tooth defect and edentulous dentition. The key to success of dental implant lies in physical osseointegration between bone tissue and implant; while the key of osseointegration lies in "bone growth" which was new bone formation around the implant and was response of the implant to the host. The low process of osseointegration was related to the biological aging of the implant surface, which reduced the influence of the biological response of the peri-implant tissues to the implant. How to immediately active the implant surface before implant is inset into bone and keep the original high biological activity is the new hot spot in the research field of Oral Implantology recently. The outstanding characteristics of using Cold, Atmospheric Pressure Plasma such as high efficiency, low energy consumption, safety, no secondary pollution, simple, and no expensive vacuum equipment and complex time-consuming procedures needed under the effect of atmospheric pressure is possiblely good for developing one fast, easy, and secure new implant surface activation technique just before oral implant surgery. This study intends to produce Cold, Atmospheric Pressure Plasma by mixture with Ar +5% O2, which was used to active the surface coated by implant titanium. Rat femur implant models were established, and titanium and HA-coated implants activated by Cold, Ar+5%O2 Plasma were implanted using self-control experimental approach to evaluate the implant osseointegration rate. Rat osteoblasts from skull were cultured and purified, then the osteoblasts were inoculated and cultivated on different titanium plates activated by Cold, Ar+5%O2 Plasma. By observing the biological behavior, such as cell adhesion, proliferation and differentiation, we hope to reveal the the mechanism of effects of Cold, Ar-O2 Plasma activated surface on implant osseointegration.

种植义齿已成为牙列缺损和牙列缺失的常规修复方法，其成功的关键在于骨结合，而骨结合的关键在于“骨生长”，即种植体周围新骨的生成。种植体表面生物活性影响骨结合进程。实验证明钛种植体表面即使经过各个表面处理后短时间内具有生物活性，但在空气中暴露之后会形成一层保护层，即发生生物老化，生物活性将大大降低。如何在种植体植入前即时的活化种植体表面并使其保持原来较高的生物学活性是近年来口腔种植领域研究的新热点，其中低温等离子体活化技术以其高效率、低能耗、安全和无二次污等优势越来越被研究者们所青睐。本实验旨在以Ar+5%O2的混合气体为输入气体产生低温等离子体，对种植体表面进行活化处理，通过外科手术方法植入大鼠股骨内，评价种植体周围的骨结合情况；并在体外进行材料与成骨细胞粘附共培养，通过观察粘附、增殖、分化等生物学行为探讨低温等离子体活化材料后的促骨结合机制，为低温等离子体对种植体表面材料活化的新途径提供实验依据。

目的：钛是最常用的牙种植体材料，但其生物老化直接影响种植体周组织细胞对种植体的生物学反应，导致骨整合过程速率降低。本研究的目的是通过低温氩氧等离子体活化生物老化的钛，使其具有高能的亲水表面，以增强材料的细胞亲和力和生物活性，并探讨活化表面对种植体骨结合的影响。.材料和方法：依据电容耦合射频放电原理，利用Ar+5%O2气体介质（220 SCCM）产生的低温等离子体对生物老化的纯钛和羟基磷灰石（HA）涂层钛片进行表面活化后，对其进行物理化学表面分析。体外培养SD大鼠颅骨成骨细胞并接种到不同的样品上以评估细胞附着和增殖。通过扫描电镜观察粘附细胞形态，并通过激光扫描共聚焦显微镜观察细胞骨架肌动蛋白；采用MTT法检测细胞在活化表面上的增殖能力；通过碱性磷酸酶（ALP）和骨钙素蛋白（OCN）含量测定成骨细胞的分化。建立大鼠股骨种植体植入模型，植入低温氩氧等离子体活化的微型种植体，并且在植入4周和8周后处死大鼠，通过Micro-CT和生物力学方法分析种植体的稳定性和骨整合情况;通过VG染色观察种植体周围骨组织形成。.结果：低温等离子体活化的样品，水接触角急剧下降，表面产生了活性氧高能基团，去除表面的含碳有机杂质，但表面未见有明显的形貌改变。等离子体活化的钛表面细胞粘附、铺展大幅改善，细胞粘附面积更大，细胞形态更多样，细胞骨架肌动蛋白形成的网络多于对照组；成骨细胞的增殖和ALP、OCN分泌也优于对照组。在等离子体活化的钛表面，细胞粘附和扩散显着增强，而成骨细胞的增殖和分化大大提高。动物实验中等离子体表面活化的钛种植体植入后骨整合率及种植体稳定性明显提高，加速了早期种植体周围骨的改建。.结论：低温氩氧等离子体可以对生物老化种植体表面进行有效活化，从而促进早期骨结合,其机制可能是等离子体活化后的表面活性基团促进了成骨细胞的粘附、增殖和分化水平。本研究为口腔种植术前的即刻表面活化提供了全新的思路。