微弧氧化/电化学沉积钙磷涂层纯钛种植体的骨内植入

背景：近年来已有对微弧氧化/电化学沉积技术制备涂层在材料性能方面的相关报道,但对这种材料植入体内的性能研究较少见。 目的：观察纯钛种植体经微弧氧化/电化学沉积处理后的骨结合和新骨形成情况。 方法：通过微弧氧化/电化学沉积方法在纯钛上制备含钙磷元素的涂层,然后将该种植体和纯钛种植体分别植入羊两侧胫骨种植窝内,于动物处死前15,5 d分别进行注射四环素进行四环素标记。术后4,12周分别进行X射线、扫描电镜及激光共聚焦观察。 结果与结论：两侧X射线表现相似,种植体周围均无明显阴影,骨小梁排列和骨质密度与宿主骨基本一致。术后4周时,在电镜下可观察到两组种植体和骨组织之间均有间隙,部分见骨性结合;术后12周时,微弧氧化/电化学沉积种植体组可形成新骨,并且新骨与种植体和原来骨组织结合紧密,涂层与钛基体没有明显间隙,纯钛种植体组也可见新骨生成,但可看到明显裂隙。激光共聚焦观察显示,微弧氧化/电化学沉积种植体组双标记带间距离及骨矿化沉积率均高于纯钛种植体组(P < 0.05)。表明微弧氧化/电化学沉积处理可增强纯钛种植体的骨结合能力及新骨形成。     

钙磷陶瓷涂层种植体—骨界面的成骨反应的定量实验研究

本文以恒河猴为实验对象,用未涂层纯钛种植体作为对照,用~(45)Ca示踪测定法及定量组织学方法研究两种生物玻璃陶瓷(MA_3)涂层种植体植入股骨后,种植体周围的骨盐沉积及新骨生长情况。结果表明:两种生物陶瓷涂层种植体的周围骨组织的钙盐沉积活跃期较未涂层者早,M-涂层种植体植入后1个月,其种植区的钙盐沉积程度就达到较高的水平。另外,在界面骨生长量方面,M-涂层植体的界面骨生长量在种植3个月内迅速增加,虽然A_4-涂层种植体的界面骨生长量在种植后3个月内高于未涂层者,但两者均通过3个月以后的继续增加,才接近于M-涂层种植体。     

直流电刺激钛种植体的实验研究

牙种植的成败,本质上取决于种植体—骨组织界面的反应。本研究的目的为探讨持续小量直流电刺激(15μA),作用于种植体对界面的影响。结果表明:界面区新骨形成的量及速度,电刺激组明显优于对照组,电刺激可明显促进新骨形成,本实验也同时证明钛种植体本身可直接做为刺激电极,电刺激种植体可望成为加速界面骨形成,从而缩短骨愈合时间的一种手段。     

正畸应力刺激下纯钛微种植体周围炎模型及骨改建

背景：种植体周围炎是影响种植体稳定性的重要因素。目的：建立正畸应力刺激下比格犬微种植体周围炎动物模型,观察其骨改建过程。方法：采用助攻法将纯钛微种植钉随机植入Beagle犬双侧上颌第二,三,四前磨牙的根分叉区,将一侧植入3枚丝线结扎的微种植体,在丝线结扎诱导微种植体周围炎后加力,分别在微种植体周围炎的第1,2,3,4周即刻施加100 g拉力,持续加力1个月。处死动物后制备含微种植体的不脱钙硬组织切片,光学显微镜观察微种植体周围炎发展不同阶段受到持续正畸应力作用下的种植体-骨界面的改建过程。结果与结论：丝线颈部接扎的微种植体植入后,颈部组织内出现大量的梭形炎性细胞,随着时间的推移,炎症逐步扩散到微种植体的尖部,有大量胶原纤维,成骨活跃,出现新生骨进行改建;周围炎发生2周后扩散到微种植体尖部,出现深浅不一的新生骨小梁组成的编织骨,炎性细胞分散,可见胶原纤维吸收后留下的髓腔不规整,骨陷窝内可见排成三四层的成骨细胞,成骨活跃。说明实验成功构建了正畸应力刺激下Beagle犬纯钛微种植体周围炎模型,受力后约2周是该模型成骨的活跃期。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

用电子探针X射线能谱分析法对口腔种植界面微区元素的动态检测

观察种植界面微区元素在种植界面形成中的作用。用电子探针X射线能谱分析方法对界面进行百分含量测定。结果表明,钛合金种植体植入后,12周内,钙元素与磷元素逐渐增加并达到峰值,以后趋于平稳,钛元素含量植入后2周较高,以后逐渐减少。种植体与机体组织之间只有极薄的一层纤维膜,已达到骨结合标准。钙元素与磷元素在骨结合界面形成过程中起主导作用,钛合金种植体植入后,短期内会释放游离离子,但不足以影响骨结合界面的形成。     

纯钛种植体表面改性对骨结合的影响

背景:研究表明,对种植体表面进行化学、物理、生物化学等改性,可以显著提高种植体表面的生物学活性和骨结合强度。目的:综述并比较不同纯钛表面改性方法对骨结合的影响。方法:以"纯钛、种植体、种植、种植体表面、表面改性、生物活性、生物相容性、骨结合、研究进展"为中文关键词,以"pure titanium,implants,plant,the surface of the implant,surface modification,biologica activity,biocompatibility,osseointegration,research progress"为英文关键词,用计算机检索CNKI数据库、万方数据库和Pub Med数据库。结果与结论:钛具有稳定的化学性能、良好的生物相容性及较高的抗断裂强度,因而在种植修复中被广泛应用,但钛种植体是一种生物惰性材料,直接植入人体后的生物相容性和生物学活性较差,影响其与骨的结合。为提高种植体骨结合强度,目前最为有效的方法是对纯钛表面进行改性。大多数研究表明,经过改性后的种植体具有一定的骨诱导作用,可促使骨细胞在其表面黏附、增殖、分化及矿化。钛种植体经过物理、化学、生物化学等改性处理后,其表面形貌、化学成分、表面粗糙度及亲水性能等发生改变,从而提高了种植体的生物相容性和生物活性,促进了骨结合的发生。     

未负载种植体骨界面形态与元素动态改变相关实验研究

观察种植界面微区元素改变与种植界面形成的关系。建立并采用种植体动物模型,应用X线观察,组织学观察,扫描电镜观察以及电子探针X射线能谱分析方法对界面进行研究。X线平片,组织学观察及扫描电镜观察表明12周时,种植体界面已形成大量新生骨组织。钛合金种植体植入后,12周内,钙元素与磷元素逐渐增加并达到峰值,以后趋于平稳,钛元素含量在植入后2周较高,以后逐渐减少。种植体与机体组织之间只有极薄的一层纤维膜,已达到骨结合标准。钙元素与磷元素在骨结合界面形成过程中起主导作用,本研究使用的钛合金种植体在实验条件下植入后,短期内会释放游离离子,但不足以影响骨结合界面的形成。     

动态加载下3种基台材料对上颌角度植入种植修复体周围骨应力的影响北大核心

背景:在口腔种植修复中,上颌前牙区单颗缺失的患者缺牙区常因不同原因导致牙槽骨吸收、缺损,为了避免植骨的风险,往往采用倾斜植入种植体的方式避开牙槽骨吸收区域,并使用角度基台恢复患者正常覆合覆盖关系,不同的基台材料传递咬合力时影响力在种植体及周围骨的大小及分布。目的:比较模拟动态加载下使用3种基台材料的种植修复体在3种植入条件下对周围骨应力峰值随时间变化关系的影响。方法:选取1例行上颌中切牙区种植修复患者的锥形束CT资料,运用Minics软件对颌骨进行切割,运用Solidworks 2018建立种植体、颌骨、角度基台(角度分别为0°,15°,25°,基台材料分别为纯钛、氧化锆、氧化铝)、中央螺丝、二氧化锆全瓷冠等模型,装配完成,以原上颌中切牙牙根方向为植入0°角,然后分别模拟腭向倾斜15°,25°植入,种植体螺纹均无暴露,按照不同植入角度分为0°组、15°组、25°组,分别进行动态加载,加载时间为0.2 s,得出各组各材料基台种植修复体周围骨等效应力峰值随时间变化的关系。结果与结论:①所有基台种植修复体在受咬合力时周围骨应力峰值分布一致,均位于种植体颈部骨皮质,各材料基台种植修复体周围骨应力上升幅度最快时间段均为0.025-0.05 s内,15°组骨皮质高应力值范围较0°组更大,25°组种植体骨皮质初始应力值明显高于其余两组,且加载结束后骨皮质残留较高应力值;钛基台种植修复体周围骨应力上升幅度最大,高应力值范围较为集中;②在15°组中,3种材料基台种植修复体周围骨应力峰值均位于种植体颈部,应力上升幅度钛基台种植修复体周围骨应力上升幅度较大但并不明显,高应力分布范围较为一致;25°组相较于其余两组应力高值较为集中,应力起始值高且变化幅度更大,其中氧化铝基台种植修复体周围骨应力在0-0.1 s内上升幅度最大,在0.2 s时氧化锆基台种植修复体骨等效应力峰值降为0,其余两种材料基台种植修复体周围骨内均残留较高应力;③结果提示,植入角度及基台材料的不同影响应力在种植体骨界面的分布,采用氧化锆材料基台的种植修复体各时间点骨应力均较为稳定。     

钛种植体表面改性策略及对骨整合的影响

背景：纯钛因具有优良的生物相容性、机械性能和与骨组织相近的弹性模量等被广泛应用于口腔种植领域。 目的：综述近年来钛金属种植体材料表面物理改性、化学改性和生物化学改性策略的研究进展。 方法：以“titanium,implant,surface modification,osseointegration”为检索词,检索PubMed数据库,以“钛,种植体,表面改性,骨整合”为检索词,检索中国知网数据库,限定时间范围为2007年1月至2013年2月。文献检索语种为英文和中文。纳入内容与钛种植体表面改性方法及其对骨整合影响密切相关的文献,排除重复文献。 结果与结论：计算机初检得到199篇文献,根据纳入排除标准,对其中76篇文献进行分析。钛种植体本身是生物惰性材料,通过表面改性对钛金属表面进行活化处理,使之具有生物功能性,与骨组织形成早期骨整合,是国内外口腔种植材料研究的热点问题。物理改性、化学改性和生物化学改性可缩短钛种植体种植周期,获得早期骨整合和更高的结合强度。今后的发展趋势是将多种改性方法有机结合,从分子水平深入研究钛金属材料表面与机体细胞和组织之间的界面分子作用机制,完善种植体的表面改性技术,实现种植体和骨组织的早期和更加稳定的骨整合。     

阳极氧化伴水热处理制备纯钛羟基磷灰石薄涂层

为了解纯钛阳极氧化伴水热处理的技术路线及羟基磷灰石薄涂层在体内的成骨效应，以钛片为阳极，β－磷酸甘油钠和醋酸钙为电解质，经200－400V直流电解15min，维持电流密度≤50mA/cm^2，而后经280℃－300℃水热处理2h，取光滑，喷砂表面作对照，分别植入12只兔股骨内，枯术后4，8，16周取出带种植体骨块制作磨片，观察新骨生成情况及术后8周光滑和涂层种植体的界面超微结构，并作表面能谱分析，结果发现水热处理后，钛片表面出现了羟基磷灰石涂层，动物实验显示涂层种植体8周后编织骨的转化和成熟较快，未见剥脱的羟基磷灰石碎片，其表面的钙，磷含量在种植后增加明显，这说明阳极氧化伴水热处理可以制备出纯钛表面羟基磷灰石薄涂层，其早期促编织骨形成作用明显，可以加快编织骨转化成板层骨。     

Bioactive films on metallic surfaces for osteoconduction

A fast and effective electrochemical method was developed to make a dense calcium phosphate films on titanium and stainless steel for hard tissue replacement. The surfaces of titanium and stainless steel were cathodically treated in an electrochemical cell. By controlling the treatment parameters, a film of 100-nm thickness was deposited on the metal surface in several minutes. The thin film was amorphous calcium phosphate containing octacalcium phosphate nuclei, and also dense and ductile. The treated metals were able to induce bioactive calcium phosphate deposition after immersion in simulated body fluid (SBF) for only 1 and 2 days. In vivo study was conducted by implanting the treated specimens of titanium and stainless steel in dog's femur cavity. The treated metallic surfaces showed good ability of osteoconduction. This surface treatment method can be potentially used to enhance bioactivity of any type of metallic surfaces.     

Electrochemical studies on the influence of proteins on the corrosion of implant alloys

The effect of proteins on corrosion rates of 316L stainless steel, commercially pure titanium and titanium 6-aluminium 4-vanadium was studied in the static and fretting modes. The static mode was studied using cylindrical specimens as per ASTM F-746, and static fracture fixation plates. The fretting mode was studied using a two-hole plate fretting machine which caused a cyclic rocking motion between the plate and the screws, as per ASTM F-897. Electrochemical techniques of polarization resistance and Tafel slope measurements were used to study effects of proteins on the anodic and cathodic corrosion reactions. It was found that proteins increased the corrosion rate of the stainless steel and C.P. titanium cylindrical specimens, but did not have an effect on the Ti-6AI-4V cylinders. In the fretting mode proteins decreased the corrosion rate of the stainless steel plates, but did not have an appreciable effect on either of the titanium alloys. The presence of proteins appeared to cause an increase in the anodic Tafel constant and a decrease in the cathodic Tafel constant of stainless steel specimens. Significant differences in the shapes of the cathodic Tafel slopes were also seen with cylinders with different surface conditions, and static versus fretting plates.     

An ultrastructural characterization of the interface between bone and sputtered titanium or stainless steel surfaces

Experimental implants of polycarbonate covered with a thin metallic layer were inserted in the rabbit tibial metaphysis. The implants had either a magnetron sputtered 316 L stainless steel or commercially pure titanium surface (or an evaporated commercially pure titanium surface). The aim of the experiment was to investigate the interfacial arrangements between bone and the coatings used. Three months after implant insertion, the animals were sacrificed and the intact interface between bone and metal analysed using ultrastructural techniques. In the case of stainless steel a coat of 1-2 cellular layers separating the bone from the metal was found. Inflammatory cells were abundant as well as a wide proteoglycan coat lacking collagen filaments. In the case of titanium there were no cells in the interface which consisted instead of a proteoglycan layer of about 200-400 A width. Bundles of collagen appeared at a minimum distance of 1000-2000 A from the metal surface. Calcium deposits were sometimes seen in direct contact (resolution level 30-50 A) with the titanium oxide. There were no ultrastructural differences in tissue reactions when magnetron sputtered titanium surfaces were compared with evaporated ones.     

The influence of titanium surface treatments on the wear of medical grade polyethylene

Abnormally high wear rates of ultra high molecular weight polyethylene have been associated with sliding against freshly polished titanium. The wear rate can be brought to the level associated with stainless steel and cast Co-Cr-Mo alloy on polyethylene by the growth of a passive film on titanium. This can be accomplished either in air at elevated temperatures or in oxidizing aqueous solutions.     

A comparison of materials for percutaneous connectors

The behavior of solid percutaneous connectors made of gold, stainless steel, vitreous carbon and titanium was studied in humans. Evaluation parameters were biocompatibility studied by conventional histochemical methods, surface degradation studied by scanning electron microscopy, and electrical impedance. The results showed after two months very slight inflammatory reaction for carbon and titanium and moderate epidermal downgrowth. In stainless steel, histology showed a somewhat more pronounced reaction, whereas in gold, there was a macroscopic inflammatory reaction. No signs of surface degradation was found in any of the materials. The electrical impedance was constant throughout the experiment. It is concluded that of the materials investigated, vitreous carbon and titanium are preferable in percutaneous connector applications. The higher impedance seen in vitreous carbon favors the use of titanium in electrical stimulation. Careful surgery with minimal trauma, controlled surface characteristics and a pure inert material are termed factors of importance to make percutaneous connector applications successful. This project was supported by The Swedish Board for Technical Development and The Neubergh Foundation.     

腹腔镜手术悬吊系统的设计与仿真分析

目的 基于现有的气腹装置,在低气压的前提下,设计一款用于微创手术的新型悬吊系统,以暴露更多手术视野,便于手术顺利进行。方法 利用Solidworks软件完成悬吊系统的结构设计,并基于有限元仿真分析技术,研究医用不锈钢、钛合金Ti6Al4V、钛合金Ti6Al7Nb和纯钛4种不同夹子制作材料以及尼龙(polyamide-6,PA6)、涤纶、聚丙烯(polypropylene, PP)3种不同中间平面结构制作材料对悬吊系统使用性能的影响。结果 4种不同材料的夹子在夹持组织过程中,组织的形变量均较低,不会出现所夹持组织从夹子中滑脱的现象。就应力而言,选用医用不锈钢材料时,夹子及其夹持组织的应力均最低;对于中间平面结构的制作材料而言,当选取涤纶材料时,在悬吊系统工作过程中,中间平面结构会在外载荷作用下发生破坏;当选用PP材料时,中间平面结构会发生永久变形,且形变量最高,不利于临床手术的进行。结论 选择医用不锈钢作为夹子的制作材料为最佳。不宜选择涤纶作为中间平面结构的制作材料,选择PA6作为中间平面结构的制作材料为最优。     

三种固定方法在颅骨骨瓣回复固定模型中生物力学评价的实验研究

目的对三种骨瓣固定方法在颅骨骨瓣回复固定模型中的生物力学性能进行比较、评价。方法6个颅骨标本共制备24个骨瓣,分为三组,分别采用丝线、不锈钢丝和颅骨固定钉三种方法固定,就操作时间、初始移位、垂直受力试验及最大承受力等方面进行比较。结果颅骨固定钉组的操作时间最短(94±13)s,初始移位最小(0.20±0.12)mm,最大承受力最大(385.4±63.1)N均明显优于不锈钢丝组和丝线组。结论颅骨固定钉操作简便快速,具有良好的复位效果及较大的强度,是较理想的颅骨固定装置。     

钛合金内固定材料修复脊柱结核：生物相容性及力学性能

BACKGROUND: Currently, surgical implant fixation is mainly applied for spinal tuberculosis. How to choose implant materials, however, is still under discussion. OBJECTIVE: To compare the biocompatibility and mechanical properties of titanium alloy and stainless steel for rabbit spinal tuberculosis. METHODS: Thirty rabbits were chosen to prepare spinal tuberculosis models. Then, the rabbits were equivalently randomized into two groups, which underwent implant fixation with stainless steel or titanium alloy, respectively. At 30 days after implantation, biocompatibility and biomechanical properties of the two materials in the repaired region of spine were observed and detected, respectively. RESULTS AND CONCLUSION: In view of the biocompatibility, infection and immunological rejection could not been found in the titanium alloy group; in contrast, infection appeared in three rabbits of the stainless steel group. Flexion, extension and lateral bending displacements under the spinal loading in the titanium alloy group were significantly less than those in the stainless steel group (P < 0.05); axial pull-out strength in the titanium alloy group was significantly higher than that in the stainless steel group (P < 0.05); flexion, extension, lateral bending and axial compression in the titanium alloy group were significantly greater than those in the stainless steel group (P < 0.05). In conclusion, titanium alloy material has good biocompatibility that can be used to restore and maintain the spinal stability.     

The influences of electrical potential and surface finish on the fatigue life of surgical implant materials.

The influence of both imposed anodic potential in Ringer's solution and surface finish on the fatigue lives of annealed 316 type stainless steel and annealed pure titanium were measured and statistically compared to fatigue data run in air. The applied potentials in simulated extracellular fluid approximated conditions existing within the body while also producing the types of surface defects actually found on removed long time implants within the time interval of the accelerated R. R. Moor fatigue tests. Differentiating tests were run at single levels of applied cyclic stress well above the endurance limits. In Ringer's solution, the fatigue life of the 316 stainless steel decreased with increasing applied potential, and at +500 mV was significantly shorter than when run in air. At each condition, the 316 stainless steel was independent of initial surface finish. In contrast, the fatigue life of titanium improved rapidly with increasingly fine surface finishes. Furthermore, compared to air, the application of +500 mV in Ringer's solution improved the life of the rough surface finished material and markedly increased to number of cycles to failure for the electopolished specimens.     

Biocompatibility and hemocompatibility of surface-modified NiTi alloys

Nickel titanium (NiTi) shape memory alloys have been investigated for several years with regard to biomedical applications. However, little is known about the influences of surface modifications on the biocompatibility of these alloys. The effects of a range of surface treatments were investigated. Cytotoxicity and cytocompatibility studies with both fibroblast and endothelial cells showed no differences in the biocompatibility of any of the NiTi surfaces. The cytotoxicity and cytocompatibility of all surfaces were favorable compared to the controls. The hemolysis caused by a range of NiTi surfaces was no different from that caused by polished 316L stainless steel or polished titanium surfaces. The spreading of platelets has been linked to the thrombogenicity of materials. Platelet studies here showed a significant increase in thrombogenicity on polished NiTi surfaces compared to 316L stainless steel and pure titanium surfaces. Heat treatment of NiTi was found to significantly reduce thrombogenicity, to the level of the control. The XPS results showed a significant decrease in the concentration of surface nickel with heat treatment and changes in the surface nickel itself from a metallic to an oxide state. This correlates with the observed reduction in thrombogenicity.