二氧化钛纳米管对兔胫骨内种植体旋转扭力的影响

The removal torque of titania nanotubes in rabbit tibia

目的通过兔子动物模型评估种植体表面不同管径的TIO_2纳米管对成骨细胞黏附、种植体扭力和成骨基因表达的影响。方法将24个订做的螺旋状的长为6 mm,外径为2.5 mm的纯钛种植体分为3组。A组:对照组平滑面种植体;B组:表面为30 nm管径TiO_2纳米管的种植体;C组:表面为70 nm管径TiO_2纳米管的种植体。分别将种植体植入兔子胫骨,手术后四周,处死兔子,采用数字扭力仪通过反向旋转取下腿部种植体,测量种植体扭力,通过扫描电子显微镜分析种植体表面成骨细胞的粘附,通过实时PCR检测核心结合因子(Runx2)、胰岛素样生长因子(IGF)、I型胶原(col-1)和骨钙素(OCN)的基因表达水平。结果表面为70 nm管径TiO_2纳米管的种植体可以增强兔胫骨内种植体的扭力(P<0.05),并显著性的提高Runx2、IGF、col-1和OCN等成骨基因的表达水平(P<0.05)。结论相对于30 nm管径纳米管,表面为70 nm管径纳米管的种植体可以获得良好的成骨反应,并且在早期植入期具有较高的界面强度。

Objective To evaluate the removal torque,osteoblast adhesion and gene expression of different TiO_2 nanotubes implant with the rabbit model. Methods A total of 24 custom-made,screw-shaped,commercially pure titanium implants with length of 6 mm and an outer diameter of 2. 5 mm were divided into 3 groups. Group A： the control implant is machined. Group B： eight implants anodized with 30 nm nanotubes. Group C： eight implants anodized with 70 nm nanotubes. Four weeks after the surgery,the rabbits were sacrificed. Subsequently,the leg was stabilized and the implant was removed under reverse torque rotation with a digital torque gauge.Osteoblast adhesion was analyzed with scanning electron microscope. The gene expression of Runt-related transcription factor2（ Runx2）,Insulinlike growth factors（ IGF）,collagen-I（ col-1） and osteocalcin（ OCN） were examined by using real-time PCR. Results The results showed that implants anodized with 70 nm nanotubes could enhance removal torque in rabbit tibia and significantly improve the Runx2、IGF、col-1 and OCN gene expression level（ P〈0. 05）. Conclusion The implants with large diameter nantubes achieved favorable osteoblast response and a higher interfacial strength at an early implantation period compared with the machined titanium implants and small diameter nantube implants.