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1.
目的为促进钛合金植入体与骨的结合,在其表面制备了生物玻璃/羟基磷灰石复合涂层,并植入兔子股骨内进行动物试验,采用等离子喷涂羟基磷灰石涂层和未涂层的Ti6Al4V合金作为对照。方法种植到期的植入体取出后进行组织学切片,采用品红-苦味酸染色后进行组织学观察,采用SEM高倍观察种植体与骨的结合界面,并对骨接触率和凹槽内骨长入量进行了统计分析和比较。结果三种植入体都具有良好的生物相容性。Ti6Al4V合金与骨之间是一种形态固定,而生物玻璃/羟基磷灰石涂层、等离子喷涂羟基磷灰石涂层可与骨形成骨键合。生物玻璃/羟基磷灰石涂层在植入期间与基体没有脱落,同时其与骨的接触率和凹槽内骨长入量要明显高于其余两个植入体,显示出促进骨生长的作用。结论由于具有良好的生物相容性和促进新骨生长的能力,生物玻璃/羟基磷灰石涂层可加快植入体与骨的愈合速度,在骨替代修复方面显示出优势和广阔的应用前景。  相似文献   

2.
背景:降钙素具有提高骨量、骨质量,降低骨折发生的效果。 目的:评价鲑鱼降钙素对羟基磷灰石植入体骨整合的影响,及其在治疗骨质疏松症同时促进植入体生物学固定的能力。 方法:将SD大鼠随机分为假手术+羟基磷灰石棒组、卵巢切除+羟基磷灰石棒组、卵巢切除+降钙素+羟基磷灰石棒组,后2组建立绝经后骨质疏松动物模型。建模后分别在3组大鼠的胫骨平台处开孔植入多孔羟基磷灰石假体,卵巢切除+降钙素+羟基磷灰石棒组大鼠皮下注射鲑鱼降钙素12周。 结果与结论:卵巢切除后,大鼠的腰椎骨密度降低,而持续皮下注射鲑鱼降钙素后,大鼠的腰椎骨密度逐渐改善。应用降钙素处理后的大鼠,其骨结合率较卵巢切除+羟基磷灰石棒组提高了22.0%(P < 0.05)。结果证实,全身给予鲑鱼降钙素能提高骨质疏松大鼠骨床和植入体周围骨量、促进主体骨-植入体的骨整合。  相似文献   

3.
背景:有研究表明,锌可通过调节成骨细胞活性起到改善骨质疏松状态下骨对钛植入体反应的作用。 目的:观察锌离子对改善骨质疏松状态下钛植入体稳定性的作用。 方法:摘除28只雌性SD大鼠卵巢,饲养12周获得骨质疏松效果,后随机分为2组,实验组于双侧股骨干骺端植入含锌羟基磷灰石涂层的钛植入体,对照组于双侧股骨干骺端植入羟基磷灰石涂层钛植入体。两组分别随机选择3只大鼠进行双重荧光标记,于术后6周末计算矿物沉积率;术后12周末,两组分别随机选择4只大鼠进行植入体及其周围组织组织形态学分析;术后12周,对两组剩余大鼠行推出实验,计算最大推出力与最大剪切力。 结果与结论:荧光标记检测发现在术后3-5周,两组中植入体周围均有活跃的骨生成,实验组矿物质沉降率显著高于对照组(P < 0.05)。两组中均可见新骨形成,但实验组新骨形成量、骨面积比率、骨-植入体接触率、最大推出力及最大剪切力均优于对照组(P < 0.05或P < 0.01)。表明锌离子在去势大鼠骨植入体中具有促进骨生成和改善植入体稳定性的作用。  相似文献   

4.
Primary cementless joint replacement depends partly on the ability of bone to heal into those areas of an inserted implant where a gap to surrounding bone initially exists. A new bone preparation technique, compaction, has enhanced gap-healing around grit-blasted implants without osteo-conductive properties. However, hydroxyapatite (HA) porous-coated implants with osteo-conductive properties are often inserted clinically to enhance gap healing and implant fixation. It is unknown whether the osteo-conductive properties of HA porous-coated implants might overwhelm the beneficial effects of compaction on gap healing. Therefore, we compared the compaction technique with the conventional bone-removing technique, drilling, using HA porous-coated implants in a canine gap model. HA porous-coated titanium implants were bilaterally inserted into oversized cavities of the proximal humeri of seven dogs. Each dog served as its own control. Thus, one humerus had the implant cavity prepared with compaction, the other with drilling. Two weeks after surgery push-out test and histomorphometry was performed. Compaction significantly increased ultimate shear strength, energy absorption, apparent shear stiffness, bone implant contact, and peri-implant bone density. The results of this study suggest that compaction may enhance gap healing when osteo-conductive HA porous coated implants are inserted in joint replacements.  相似文献   

5.
For the last 15 years, orthopedic implants have been coated with hydroxyapatite (HA) to improve implant fixation. The osteoconductive effect of HA coatings has been demonstrated in experimental and clinical studies. However, there are ongoing developments to improve the quality of HA coatings. The objective of this study was to investigate whether a rough and highly crystalline HA coating applied by vacuum plasma spraying (VPS) had a positive effect on the osseointegration of special, high-grade titanium (Ti) implants with the same surface roughness. Ti alloy implants were coated (VPS) with special, high-grade Ti or HA. The osseointegration of the implants was evaluated by either light microscopy or pullout tests after 1, 2, and 4 weeks of unloaded implantation in the cancellous bone of 18 sheep. The interface shear strength increased significantly over all time intervals. By 4 weeks, values had reached approximately 10N/mm(2). However, the difference between the coatings was not significant at any time interval. Direct bone-implant contact was significantly different between the coatings after 2 and 4 weeks, and reached 46% for Ti and 68% for HA implants by 4 weeks. This study indicates that the use of a rough and highly crystalline HA coating, applied by VPS, enhances early osseointegration. Accelerated establishment of secondary implant fixation decreases the risk of early loosening.  相似文献   

6.
Bone ingrowth in bFGF-coated hydroxyapatite ceramic implants   总被引:3,自引:0,他引:3  
This experimental study was performed to evaluate angiogenesis, bone formation, and bone ingrowth in response to osteoinductive implants of bovine-derived hydroxyapatite (HA) ceramics either uncoated or coated with basic fibroblast growth factor (bFGF) in miniature pigs. A cylindrical bone defect was created in both femur condyles of 24 miniature pigs using a saline coated trephine. Sixteen of the 48 defects were filled with HA cylinders coated with 50 microg rhbFG, uncoated HA cylinders, and with autogenous transplants, respectively. Fluorochrome labelled histological analysis, histomorphometry, and scanning electron microscopy were performed to study angiogenesis, bone formation and bone ingrowth. Complete bone ingrowth into bFGF-coated HA implants and autografts was seen after 34 days compared to 80 days in the uncoated HA group. Active ring-shaped areas of fluorochrome labelled bone deposition with dynamic bone remodelling were found in all cylinders. New vessels could be found in all cylinders. Histomorphometric analysis showed no difference in bone ingrowth over time between autogenous transplants and bFGF-coated HA implants. The current experimental study revealed comparable results of bFGF-coated HA implants and autogenous grafts regarding angiogenesis, bone synthesis and bone ingrowth.  相似文献   

7.
Ti (PG60) and Ti plus HA (HPG60) dense coatings with ultrahigh roughness (Ra: 74 +/- 8 microm and 53 +/- 18 microm, respectively) were compared to high Ti (Ti60) and Ti plus HA (HT60) high roughened porous coatings (Ra: 40 +/- 7 microm and 36 +/- 3 microm, respectively). Surfaces were implanted in cortical and trabecular bone of young adult (YOUNG), aged (AGED) and estrogen-deficient sheep (OVX) and analyzed by means of histology, histomorphometry and push-out tests 3 months after implantation. A significantly lower value in affinity index (AI) of PG60 when compared to TI60 (p < 0.01) was observed in cortical bone. In trabecular bone, lower values in AI were found in TI60 and PG60 when compared to their HA-coated surfaces (p < 0.0005). Bone ingrowth (BI) of TI60 and PG60 was significantly lower than that of the HA-coated surfaces in trabecular bone (p < 0.05). Significantly lower values in BI in OVX sheep in comparison to YOUNG sheep in both cortical and trabecular bone were observed (p < 0.05). Data showed that high roughness and Ti and HA-coated surfaces are suitable for aged and osteoporotic patients. HA coatings represent the most successful strategy in trabecular bone.  相似文献   

8.
In order to improve the bioactivity of titanium, an original surface treatment was attempted with the use of a casting technique was attempted. Pure titanium was cast into a special graphite mold in which the cavity wall was coated with hydroxyapatite (HA) powder. According to analyses of X-ray diffraction and EDX, the existence of HA and CaO and uptake of Ca and P on the surface of the titanium castings were identified. By immersing the specimen in Hank's solution, the concentrations of Ca and P on the surface increased with immersion time, and the formation of a thin layer with characteristics of spherical HA precipitates was observed after 1 week. The concentrations of Ca and P elements and the Ca/P ratio on the HA layer increased with immersion time. The formation of the HA layer on the titanium cast by this treatment was significantly accelerated compared with pure titanium. The present surface treatment of Ti is expected to improve early bone fixation of Ti implants.  相似文献   

9.
The influence of wear debris on bone healing around orthopedic implants is debated. Hydroxyapatite (HA) particles and polyethylene (PE) particles have been shown to have a negative effect on osteoblast cultures in vitro. The present study investigated the in vivo effects of HA and PE particles on the mechanical fixation and gap healing around experimental HA implants. Nonloaded implants (n = 30) were inserted bilaterally into the proximal tibia of 15 dogs with a 2-mm gap to the bone. The peri-implant gap was either (1) empty (n = 6) or filled with (2) hyaluronic acid (n = 8), (3) hyaluronic acid and HA particles (n = 8), or (4) hyaluronic acid and PE particles (n = 8). After 4 weeks, the animals were killed. The implant interface was evaluated by pushout testing until failure and by histomorphometry. Both HA and PE particles were found to be phagocytosed by macrophage-like cells in the interfacial tissue. HA particles were also integrated in newly formed bone. We found no negative effect of the particulate material on mechanical fixation of the implants or on bone formation around the implants.  相似文献   

10.
Roentgen Stereophotogrammetric Analysis (RSA) studies have shown that the quality of the early fixation of implants has a dominant effect on their long-term function. To evaluate methods to improve their fixation, we examined the influence of mechanical loading and surface coating on the quality of the bone-implant interface. We compared the fixation of a cylindrical, stable 6.0 mm implant initially surrounded by a 0.75 mm concentric gap, after 4 weeks of loaded or unloaded conditions. Two types of surfaces were analyzed: plasma sprayed hydroxyapatite (HA) and plasma sprayed titanium (Ti). The histomorphometric evaluation showed that HA implants had greater bone coverage than Ti implants, and this coverage was further increased under loaded conditions only for HA. Furthermore, loading reduced the fibrous tissue coverage for the HA implants, while it increased fibrous tissue coverage for Ti implants. These findings were in agreement with pushout results showing that HA implants had greater shear strength, stiffness, and energy than Ti implants, and (except for energy) these parameters were further increased under loaded conditions only for HA. In addition, because the two implant surfaces exhibited a different relative response to load, it is important to evaluate new surfaces under the more clinically relevant loaded condition.  相似文献   

11.
A study was designed to investigate the osseointegration of titanium implants, either noncoated or coated with hydroxyapatite (HA), into rabbit tibiae in the presence of local infection compared with osseointegration in the absence of local infection. HA-coated or noncoated Ti cylinders were implanted into both tibiae of 32 rabbits (New Zealand Whites). Before implantation the left tibia was contaminated with different quantities of Staphylococcus aureus (10(2)-10(5) CFU). Four weeks after surgery the tibiae were explanted and prepared for microbiological and histomorphometrical examination. Histomorphometrical data, as a representation of implant fixation, were obtained by measuring the percentage of bone around the implants (within a radius of 1 mm from the outer diameter of the implants) and the percentage of the circumference of the implant that was in direct contact with bone. Histomorphometry revealed, in particular for the HA implants, a relationship between the inoculum concentration and/or the presence or absence of infection with the bone contact at the distal implant side. This confirms a relationship between peri-implant infection and bone contact or remodeling. HA-coated implants developed, in the presence of bacteria, more easily a more severe infection than noncoated Ti implants, and we show in the present study that local infection will influence histomorphometrical parameters (bone-implant contact) that determine implant fixation. Precautions to prevent contamination (asepsis) and/or infection (perioperative antibiotics) are even more important for the highly biocompatible HA-coated implant.  相似文献   

12.
The aim of the present study was to analyze the in vivo effect of biomimetic calcium phosphate coating of titanium implants on periimplant bone formation and bone-/implant contact. Five types of implants were used: 1) Ti6Al4V implants with a polished surface; 2) Ti6Al4V implants with collagen coating; 3) Ti6Al4V implants with a mineralized collagen layer; 4) Ti6Al4V implants with sequential coating of hydroxyapatite (HA) and collagen; and 5) Ti6Al4V implants with HA coating only. All implants had square cross sections with an oblique diameter of 4.6 mm and were inserted press fit into trephine burr holes of 4.6 mm in the mandibles of ten beagle dogs. The implants of five animals each were evaluated after a healing period of 1 month and 3 months, respectively, during which time sequential fluorochrome labeling of bone formation had been performed. Bone formation was evaluated by morphometric measurement of the newly formed bone around the implants and the percentage of implant bone contact. After 1 month, there was a significantly higher percentage of mean bone/implant contact in the HA-coated implants compared to those with polished surface and those with the collagen-coated surface. After 3 months, these differences were not present anymore. Bone apposition was significantly higher next to implants with sequential HA/collagen coating compared to polished surfaces and mineralized collagen layer. It is concluded that biomimetic coating of titanium implants with HA has shown the clearest trend to increase bone-implant contact in the early ingrowth period. The addition of collagen to an HA coating layer may hold some promise when used as sequential HA/collagen coating with mineralized collagen as the surface layer.  相似文献   

13.
去势大鼠骨形态计量学、生物性能变化   总被引:2,自引:0,他引:2  
目的 通过观察大鼠血清学、骨形态计量学测定、骨生物性能等方法研究去卵巢大鼠骨变化.方法 采用7-12月龄SD雌性大鼠30只,随机分为对照组、模型组和尼尔雌醇组.模型组和尼尔雌醇组大鼠切除双侧卵巢进行造模.尼尔雌醇组大鼠造模后45天开始灌服尼尔雌醇,连续90天;对照组和模型组大鼠手术后第45天开始灌服去离子水,连续90天.所有大鼠给药第80、87天时两次ip四环素20mg/kg进行骨荧光标记.实验结束时,取出大鼠股骨及第四腰椎骨进行股骨形态计量学测定、股骨骨密度测量、股骨三点弯曲实验及椎骨压缩实验,同时测定血清碱性磷酸酶(ALP)、抗酒石酸酸性磷酸酶(StrACP)水平.结果 大鼠去双侧卵巢后,股骨骨密度、骨最大载荷、最大应力、弹性模量、刚度水平和骨小梁体积显著性提高;椎体压缩性能、股骨形态计量学、股骨弯曲性能有明显改变;而雌激素对以上变化有不同程度改善作用.结论 骨组织形态、骨生物性能是评价骨质疏松模型或药物疗效的重要指标;发生骨质疏松时,骨组织形态学变化先于骨生物性能变化.  相似文献   

14.
Early bone ongrowth is known to increase primary implant fixation and reduce the risk of early implant failure. Arg-Gly-Asp (RGD) peptide has been identified as playing a key role in osteoblast adhesion and proliferation on various surfaces. The aim for this study is to evaluate the effect of RGD peptide coating on the bony fixation of orthopaedic implants, to justify its further evaluation in clinical applications. Sixteen unloaded cylindrical plasma sprayed Ti6Al4V implants coated with cyclic RGD peptide were inserted as press-fit in the proximal tibia of 8 mongrel dogs for 4 weeks. Uncoated control implants were inserted in the contralateral tibia. Results were evaluated by histomorphometry and mechanical push-out test. A significant two-fold increase was observed in bone ongrowth for RGD-coated implants. Also, fibrous tissue ongrowth was significantly reduced for RGD-coated implants. Bone volume was significantly increased in a 0-100 microm zone around the implant. The increased bony anchorage resulted in moderate increases in mechanical fixation as apparent shear stiffness was significantly higher for RGD-coated implants. Increases in median ultimate shear strength and energy to failure were also observed. This study demonstrates that cyclic RGD coating increases early bony fixation of unloaded press-fit titanium implants.  相似文献   

15.
This study evaluated the effects of osteogenic protein 1/collagen composite (OP-1/col) mixed with impacted allograft around hydroxyapatite (HA)-coated titanium alloy implants in a canine model. The aim of the study was to test different doses of OP-1 growth factor in a collagen composite for stimulatory effect on allograft incorporation around an implant. Unloaded implants were inserted in each proximal humerus of 16 skeletally mature dogs. The cylindrical implants (4 x 9 mm) coated with HA were initially surrounded by a 3-mm gap into which allograft mixed with OP-1/col was impacted. Two different doses of OP-1 were investigated. In eight animals 325 mg OP-1 protein and 130 mg bovine collagen type I as carrier were mixed with the allograft chips.This composite is identical to the clinically used OP-1 device called Novus. In another eight animals a lower dose of 65 mg OP-1 protein and 130 mg bovine collagen type I was used. Control implants placed in the contralateral humerus were surrounded by allograft mixed with collagen carrier only. The dogs were euthanized at 6 weeks. Implant fixation was determined by push-out testing. Bone ingrowth and bone formation were evaluated by quantitative histomorphometry on serial sections of the bone-implant interface. Impacted allograft together with low-dose OP-1 enhanced bone volume in a zone adjacent to HA-coated titanium alloy implants. The high dose had no effect on bone formation. Mechanical fixation, bone ingrowth, and bone volume in the gap near the original trabecular bone were unaffected by both low and high OP-1/col composite. In this model and observation period, the low dose of OP-1/col composite mixed with impacted allograft has a moderate effect on bone healing around HA-coated implants and no effect on implant fixation.  相似文献   

16.
Ong JL  Carnes DL  Bessho K 《Biomaterials》2004,25(19):4601-4606
In this study, bone interfacial strength and bone contact length at the plasma-sprayed hydroxyapatite (HA) and titanium plasma-sprayed (TPS) implants were evaluated in vivo. Non-coated titanium (Ti) implants were used as controls. Cylindrical coated or non-coated implants (4.0mm diameter by 8mm long) were implanted in the dogs' mandibles. Loading of the implants was performed at 12 weeks after implantation. At 12 weeks after implantation (prior to loading) and 1 year after loading, implants were evaluated for interfacial bone-implant strength and bone-implant contact length. No significant differences in interfacial bone-implant strength for all groups at 12 weeks after implantation and after 1 year loading in normal bone were found. However, bone contact length for HA implants was significantly higher than the TPS and Ti implants for both periods tested (12 weeks after implantation and 1 year after loading). It was concluded that TPS implants exhibited similar pull-out strength compared to the HA implants. In addition, the lower bone contact length on the TPS surface compared to HA surfaces did not affect the interfacial bone-implant strength for both implants.  相似文献   

17.
An in vivo study was carried out on uncoated and hydroxyapatite (HA)-coated nanostructured Ti13Nb11Zr alloy in comparison with high-grade Ti6Al4V, to investigate the effect of the different surfaces on osteointegration rate. A highly effective method to obtain a fast biomimetic deposition of a thin layer of nanocrystalline HA was applied to coat both substrates. Cylindrical pins were implanted in rabbit cortical bone and evaluated at 4 and 12 weeks by histomorphometry and microhardness tests. The results confirmed the ability of the slightly supersaturated Ca/P solution to induce a fast deposition of nanocrystalline HA on Ti alloys' surfaces. HA-coated Ti13Nb11Zr had the highest osteointegration rate at 4 and 12 weeks. Both HA-coated surfaces showed an affinity index significantly higher than those of native surfaces at 4 weeks (Ti13Nb11Zr+HA: 37%; Ti6Al4V+HA: 26%). Microhardness test showed a significantly higher bone mineralization index of HA-coated Ti13Nb11Zr in comparison with that of HA-coated Ti6Al4V surface. The study suggests that the HA coating on both alloys enhances bone response around implants and that there is a synergic effect of Ti-Nb-Zr alloy with the HA coating on bone remodeling and maturation.  相似文献   

18.
We compared early fixation of titanium implants grafted with impacted allograft bone or coralline hydroxyapatite (HA) granules (Pro Osteon 200) with and without the addition of concentrated bone marrow cells (BMC). Autologous bone marrow aspirate was centrifuged to increase the BMC concentration. Four nonloaded cylindrical, porous coated titanium implants with a circumferential gap of 2.3 mm were inserted in the proximal humeri of eight dogs. Coralline HA granules +/- BMC were impacted around the two implants on one side, and allograft +/- BMC was impacted around the contra lateral implants. Observation time was 4 weeks. The implants surrounded by allograft bone had a three-fold better fixation than the HA-grafted implants. The concentration of BMC after centrifugation was increased with a factor 2.1. The addition of BMC to either of the bone graft materials had no statistically significant effects on implant fixation. The allografted implants were well osseointegrated, whereas the HA-grafted implants were largely encapsulated in fibrous tissue. The addition of concentrated autologous BMCs to the graft material had no effect on implant fixation. The HA-grafted implants were poorly anchored compared with allografted implants, suggesting that coralline HA granules should be considered a bone graft extender rather than a bone graft substitute.  相似文献   

19.
《Acta biomaterialia》2014,10(6):2855-2865
Coating titanium implants with artificial extracellular matrices based on collagen and chondroitin sulfate (CS) has been shown to enhance bone remodelling and de novo bone formation in vivo. The aim of this study was to evaluate the effect of estrogen deficiency and hormone replacement therapy (HRT) on the osseointegration of CS-modified Ti implants. 30 adult female, ovariectomized Wistar rats were fed either with an ethinyl-estradiol-rich diet (E) to simulate a clinical relevant HRT or with a genistein-rich diet (G) to test an alternative therapy based on nutritionally relevant phytoestrogens. Controls (C) received an estrogen-free diet. Uncoated titanium pins (Ti) or pins coated with type-I collagen and CS (Ti/CS) were inserted 8 weeks after ovarectomy into the tibia. Specimens were retrieved 28 days after implantation. Both the amount of newly formed bone and the affinity index (P < 0.05) were moderately higher around Ti/CS implants as compared to uncoated Ti. The highest values were measured in the G-Ti/CS and E-Ti/CS groups, the lowest values for the E-Ti and G-Ti controls. Quantitative synchrotron radiation micro-computed tomography (SRμCT) revealed the highest increase in total bone formation around G-Ti/CS as compared to C-Ti (P < 0.01). The effects with respect to direct bone apposition were less pronounced with SRμCT. Using scanning nanoindentation, both the indentation modulus and the hardness of the newly formed bone were highest in the E-Ti/CS, G-Ti/CS and G-Ti groups as compared to C-Ti (P < 0.05). Coatings with collagen and CS appear to improve both the quantity and quality of bone formed around Ti implants in ovarectomized rats. A simultaneous ethinyl estradiol- and genistein-rich diet seems to enhance these effects.  相似文献   

20.
背景:提高钛种植体的抗菌性能,降低种植体周围炎的发生,是提高钛种植体成功率的有效方法。 目的:观察含锌羟基磷灰石二氧化钛复合涂层的抗菌性能。 方法:在纯钛表面先通过微弧氧化方法形成多孔二氧化钛,然后通过溶胶-凝胶法在其上形成含锌羟基磷灰石二氧化钛生物涂层。采用电感耦合等离子发射光谱仪测定各组钛样品Zn2+的释放浓度;通过抑菌实验及扫描电镜观察接种于复合涂层钛样品表面的牙龈卟啉单胞菌黏附数量和形态。 结果与结论:在Tris缓冲液中Zn2+的释放浓度随着前体溶液中Zn/Ca摩尔比的增加而增加,牙龈卟啉单胞菌在复合涂层钛样品表面生长受到明显的抑制,黏附在材料表面的细菌形态发生改变。结果可见含锌羟基磷灰石二氧化钛复合涂层具有较好的抑菌性能。  相似文献   

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