雌激素干预吸烟骨质疏松大鼠种植体周围的骨沉积

背景：骨质疏松、吸烟可致口腔种植失败率显著增高。 目的：观察雌激素对吸烟骨质疏松大鼠种植体周围骨沉积的影响。 方法：50只雌性大鼠均分为5组：除假手术组外,卵巢去势组、卵巢去势+雌激素组、卵巢去势+吸烟组、卵巢去势+吸烟+雌激素组均制备卵巢去势模型,去势术后后两组持续熏烟24周。去势术后12周,在大鼠右侧胫骨近骺端植入钛种植体,种植后对卵巢去势+雌激素组和卵巢去势+吸烟+雌激素组肌注雌激素。实验24周时行动物活体骨密度测量及X射线观察,处死动物采集标本行种植体骨硬组织切片观察。 结果与结论：骨密度及X射线观察结果显示,雌激素可提高种植体周围骨沉积。硬组织切片观察结果显示,卵巢去势+雌激素组种植体骨包绕范围基本形成骨结合,松质骨区结合骨板与周围骨小梁相连。卵巢去势+吸烟+雌激素组种植体周围结合骨板较卵巢去势+吸烟组明显增厚,骨板周围小梁骨增多。提示雌激素可在一定程度上提高吸烟骨质疏松大鼠种植体周围骨沉积,促进种植体骨结合。     

Micro CT定量研究去卵巢山羊胫骨平台松质骨微结构特点

背景：骨质疏松时胫骨平台松质骨微结构发生显著变化,Micro CT是一种能够全面、立体、无创测量骨微结构、评估骨质量及预测骨强度的新兴技术,近年来在骨质疏松研究领域得到日益广泛的应用。 目的：应用Micro CT技术定量研究去卵巢山羊胫骨平台松质骨的微结构特点。 方法：将12只2.5岁健康雌性山羊随机分为去卵巢组和假手术组,去卵巢组行卵巢切除,假手术组切除等量腹腔脂肪组织,每组各6只。两组实验动物分别在术后2,4年处死,分离并截取左侧胫骨平台,行Micro CT扫描,分别测量胫骨平台骨骺松质骨和干骺端松质骨微结构参数。 结果与结论：术后2和4年,与假手术组相比,去卵巢组胫骨平台骨骺和干骺松质骨微观结构参数-骨体积分数、骨小梁数量和骨小梁厚度均降低(P < 0.05),骨小梁分离度均升高(P < 0.05),基本呈时间依赖性变化。仅在术后4年,去卵巢组骨骺松质骨微观结构参数骨小梁厚度与假手术组相比差异无显著性意义(P > 0.05),其骨小梁分离度、骨小梁厚度与去卵巢组术后2年相比差异无显著性意义(P > 0.05)。无论术后2或4年,与假手术组相比,去卵巢组干骺端松质骨微结构参数的改变均比骨骺松质骨明显。结果证实,山羊胫骨平台骨骺松质骨微结构参数与干骺端松质骨具有一定的差异;骨质疏松时山羊胫骨平台松质骨微结构改变呈现出区域性特点,干骺端松质骨较骨骺松质骨微结构退变更为显著。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程全文链接：     

仙珍骨宝胶囊对去卵巢大鼠股骨颈骨代谢的影响

背景：用骨组织形态计量学方法探讨中药对去卵巢大鼠股骨颈骨质疏松的影响,可为采用中药防治绝经后妇女骨质疏松性股骨颈骨折提供实验依据。 目的：观察仙珍骨宝胶囊对去卵巢大鼠股骨颈松质骨的影响。 方法：3月龄SD雌鼠随机分为4组：基础对照组于实验开始时处死取材,去卵巢组和仙珍骨宝组去卵巢造模,仙珍骨宝组在去卵巢后灌胃仙珍骨宝,去卵巢组和年龄对照组灌胃生理盐水,90 d后处死,取股骨颈经不脱钙骨制片进行骨组织形态计量学参数测量。 结果与结论：与年龄对照组比较,去卵巢大鼠静态参数的骨小梁面积百分数和骨小梁数量明显减少(P < 0.01),骨小梁间隙明显增大(P < 0.01);动态参数的每毫米破骨细胞数和破骨细胞贴壁表面长度明显增加(P < 0.01),骨矿化沉积率明显减少(P < 0.01)。说明去卵巢能导致大鼠股骨颈骨量显著减少。给予仙珍骨宝治疗后,大鼠的骨小梁厚度及骨小梁面积明显增加(P < 0.05),每毫米破骨细胞数和破骨细胞贴壁表面长度有所减少,标记周长百分数则有所增加。说明仙珍骨宝能阻止去卵巢所致的大鼠股骨颈骨量丢失。     

SD大鼠绝经后骨质疏松疾病动物模型的构建

目的构建绝经后骨质疏松疾病动物模型,探讨该疾病的发病机制与防治措施。方法将3个月龄健康雌性SD大鼠40只,随机分为2组,分别为去卵巢组和假手术组。去卵巢组切除大鼠双侧卵巢,手术后3个月通过检测体重、阴道涂片、血钙、子宫湿重、骨组织病理学、骨组织形态计量参数等对模型进行评价。结果手术后3个月,去卵巢组大鼠体重较假手术组明显增加(P0.05),子宫湿重、血钙含量较假手术组量明显下降(P0.05),阴道涂片显示去卵巢组大鼠均无发情表现,骨组织病理学观察显示去卵巢大鼠胫骨骨小梁断裂,小梁间距变宽,结构紊乱,骨形态计量学数据显示去卵巢大鼠胫骨、股骨干骺端骨小梁面积百分率、骨小梁平均厚度均较假手术组减少(P0.05)。结论 3个月龄SD大鼠去卵巢后3个月可成功复制出绝经后骨质疏松模型。     

中等强度跑台运动对去卵巢大鼠股骨头骨松质结构的影响

目的:观察中等强度跑台运动对去卵巢大鼠股骨头骨松质结构的影响,探讨运动对绝经期妇女骨质疏松的预防作用。方法:SD大鼠随机分为假手术组、去卵巢手术组、雌激素对照组和运动组。假手术组进行模拟手术不切除卵巢,其余各组行双侧卵巢切除术。手术2周后开始为期8周的干预治疗。雌激素对照组用尼尔雌醇治疗,运动组按要求进行运动。治疗结束后取股骨头骨松质进行树脂包埋及体视显微观察并进行骨组织形态计量学分析。结果:运动组的骨小梁面积、骨小梁厚度、骨小梁数量明显高于去卵巢手术组,骨小梁分离度、骨小梁游离末端数显著低于去卵巢手术组。结论:中等强度运动可以抑制去卵巢导致的大鼠股骨头骨松质骨量的丢失,确保其骨结构的维持,保证其正常的骨强度。     

高盐饮食通过激活破骨细胞促进小鼠骨质疏松发生

目的　明确高盐饮食对小鼠破骨细胞分化的影响及其促进骨质疏松的作用。 方法　获得C57小鼠骨髓单个核细胞,在体外定向诱导破骨分化体系中比较对照组（未加入氯化钠）、低剂量组（20 mmol/L氯化钠）及高剂量组（40 mmol/L氯化钠）破骨细胞生成数量;将24只C57小鼠随机平均分为正常组（普通饲料喂养）、卵巢切除组（切除卵巢,普通饲料喂养）、高盐饮食组（切除卵巢,8%高盐饲料+生理盐水喂养）,6周后分析3组左侧股骨破骨细胞生成数量并测定血清骨吸收及骨保护指标水平;选择右侧股骨进行显微CT扫描,比较3组骨组织形态计量学参数。 结果　体外高盐状态破骨细胞生成数量明显增加;体内高盐饮食组破骨细胞生成数量明显高于其它两组,I型胶原羧基端肽和核因子κ B受体活化因子配体不同程度增加,骨保护素水平显著降低,骨体积分数、骨皮质厚度、骨小梁数量和骨小梁厚度下降尤为明显,骨表面积/骨体积、骨小梁分离度和骨小梁模式因子不同程度增高。 结论　高盐饮食可通过激活小鼠破骨细胞分化及其功能活化增强骨吸收作用,进而诱导骨质疏松发生。     

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。     

组蛋白去乙酰化酶在卵巢切除小鼠骨髓间充质干细胞中的表达

背景：骨髓间充质干细胞的多向分化能力在骨代谢疾病中发挥重要作用,受激素、细胞因子等多种因素调节。目前骨髓间充质干细胞骨向分化的表观遗传学调控机制尚不明确,组蛋白去乙酰化酶与骨质疏松的关系尚需进一步探讨。 目的：建立雌激素缺乏骨质疏松小鼠的实验动物模型,检测骨髓间充质干细胞组蛋白去乙酰化酶1,3,4 mRNA表达水平,探索卵巢切除小鼠骨组织形成障碍的表观遗传学机制。 方法：昆明种小鼠30只随机等分为模型组和假手术组。小鼠适应性喂养7 d后,模型组小鼠切除双侧卵巢,造成雌激素缺乏骨质疏松实验动物模型,假手术组小鼠仅切除等量脂肪组织。 结果与结论：模型组小鼠股骨骨小梁稀疏或断裂,骨小梁宽度变窄,骨小梁间距变宽,骨小梁占视野面积降低。与假手术组相比,模型组小鼠骨髓间充质干细胞中组蛋白去乙酰化酶3 mRNA表达水平显著降低,组蛋白去乙酰化酶1,4表达水平变化差异无显著性意义。提示雌激素缺乏导致骨髓间充质干细胞去乙酰化状态改变可能是骨形成障碍的重要原因之一。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

卵巢切除对大鼠骨组织结构改变的影响

目的：探讨卵巢切除对大鼠骨组织形态学改变的影响。方法：将１８只３月龄雌性大鼠随机分为卵巢切除组及假手术组（对照组）。术后３周处死两组大鼠，获取股骨远端１／３处骨，分别进行石蜡包埋，塑料包埋切片及扫描电镜观察。结果：卵巢切除可引起大鼠骨小梁变细、中断，骨小梁表面钙盐沉积减少。结论：卵巢切除可使大鼠骨吸收增加，影响骨的稳定性，增加骨折发生的危险性。     

可注射硫酸钙修复骨质疏松大鼠股骨近端骨小梁的实验研究*

目的探讨可注射硫酸钙植入对骨质疏松大鼠股骨近端骨小梁的影响。方法复制去卵巢大鼠骨质疏松模型,采用穿刺注射技术将可注射硫酸钙植入骨质疏松实验大鼠股骨近端,对侧做自身对照,于术后2、4、8、12周取材,对双侧股骨近端行影像学、组织学观察,骨组织形态计量学及双能x线骨密度测定。结果影像学显示：术后4、8、12周实验侧股骨近端密度明显高于对照侧。骨组织学检查显示：术后4周实验侧硫酸钙降解,出现成骨效应;8周股骨近端穿刺注射区域已为致密、分化不成熟的骨小梁所填充;12周股骨近端骨小梁得到较好修复,为成熟的骨小梁组织所填充;对照侧为典型骨质疏松病理改变。骨组织形态计量学测定显示：术后8和12周实验侧骨小梁面积百分数、骨小梁宽度和骨小梁数量显著高于对照侧,实验侧骨小梁分离度显著小于对照侧。术后2、4、8、12周实验侧股骨近端骨密度较对照侧明显增加。结论可注射硫酸钙能快速有效的修复骨质疏松大鼠股骨近端骨小梁。     

The effect of oxytocin on osseointegration of titanium implant in ovariectomized rats

Introduction: Oxytocin (OT) was reported to control differentiation of human mesenchymal stem cells and reverse osteoporosis (OP). This study investigated the effect of systematical treatment of OT on implant osseointegration in ovariectomized (OVX) rats. Material and methods: Twenty female rats received bilateral ovariectomy. Twelve weeks later, all animals were randomly assigned to control or experimental group. Each rat received two implants at the distal femoral metaphysis. From the first postoperative day, rats in experiment group received subcutaneous injection of OT (1 mg/kg · d), while animals in control group received vehicle. Twelve weeks after implantation, specimens containing implants were harvested and evaluated by histology, micro-CT, and push-out test. Tibiae were also harvested to evaluate the effect of OT on intact bone tissue of OVX rats. Results: Compared with control, OT treatment increased the relative bone volume surrounding the implant by 2.2 times, the percent implant osseointegration by 0.62 times, and the maximum push-out force by 2.25 times. Increased bone mass was also observed in histological sections of distal femur with implant and intact bone tissue of the proximal tibiae. Conclusion: Systemic administration of OT promoted peri-implant bone healing and osseointegration of titanium implant and recovered the negative effects of OP in undisturbed bone tissue partially.     

具有微弧氧化-硅烷-褪黑素复合膜层钛合金种植体的体内骨结合

BACKGROUND: Imperfect strength of titanium alloy implant-bone interface delays bone healing. OBJECTIVE: In order to further improve the early healing ability of titanium dental implants, to make the surface modification of titanium alloy implant and observe the osseointegration ability of the implant. METHODS: Titanium alloy implants were coated with micro-arc oxidation (group A), micro-arc oxidation-silane (group B), and micro-arc oxidation-silane-melatonin (group C) coatings, respectively. Three kinds of implants were placed into the mandible of New Zealand white rabbits, and 2, 4, 6 weeks after implantation, implant-bone interface osseointegration was observed using cone-beam CT, fluorescence microscopy, and torsion test. RESULTS AND CONCLUSION: (1) Cone-beam CT examination: 6 weeks after implantation, the osseointegration of the implant with the mandible achieved the best results in the group C, followed by group B and group A. (2) Fluorescence microscope observation: the implants in the three groups exhibited the strongest fluorescence at 4 weeks and slightly weakened at 6 weeks, and the fluorescence intensity was higher in the group C than the other two groups. (3) Torsion test: with implantation time prolonged, the implant-bone osseointegration activity gradually increased in the three groups, while it was still highest in the group C (P < 0.05). In summary, our results show that the titanium alloy implant coated with micro-arc oxidation-silane-melatonin composite coating has higher osseointegration activity and promotes bone formation.     

Effects of glucocorticoid on BMD, micro-architecture and biomechanics of cancellous and cortical bone mass in OVX rabbits

The incidence of osteoporosis continues to increase with progressively aging populations. The purpose of this study was to detect the effects of glucocorticoid (GC) treatment on bone mineral density (BMD), biomechanical strength and micro-architecture in cancellous and cortical bone in ovariectomized (OVX) rabbits. Twenty adult female New Zealand white rabbits were randomly divided into three groups. The OVX-GC group (n=8) received a bilateral ovariectomy first and then daily GC treatment (methylprednisolone sodium succinate, 1mg/kg/day) for 4 weeks beginning 2 weeks after ovariectomy treatment. The OVX group (n=4) received a bilateral ovariectomy without GC treatment. The sham group (n=8) only received the sham operation. BMD was determined prior to and 6 weeks after the operation in the spine. Six weeks after the operation, the animals were sacrificed, and cancellous bone specimens were harvested from the femoral condyle and lumbar vertebrae. Cortical bone specimens were obtained from the femoral midshaft. The femoral specimens were scanned for apparent BMD. All specimens were tested mechanically and analyzed by microcompute tomography (micro-CT). In cancellous bone, GC treatment resulted in significant decreases in BMD, bone biomechanical strength and micro-architecture parameters in lumbar vertebrae. Similar trends in BMD and micro-architectural changes were also observed in the femoral condyle in the OVX-GC group compared with the sham group. However, there was no significant decline in any parameter in either lumbar vertebrae or femoral condyle in the OVX group. Similarly, no significant difference was found in any parameter in cortical bone among the three groups. Thus, the 4-week GC treatment in OVX rabbits could result in a significant bone loss in cancellous bone but not in cortical bone. This model is comparable to the osteoporosis-related changes in humans. OVX alone was not sufficient to induce osteoporosis.     

Ovariectomy-associated changes in bone mineral density and bone marrow haematopoiesis in rats

The relationship between the bone mass loss and bone marrow haematopoiesis in osteoporosis remains obscure. We selected 3-month-old female Sprague–Dawley rats and randomly divided them into six groups. Three groups were ovariectomized (OVX), while the other three groups were sham operated (Sham). Four, 8 and 12 weeks after the surgical procedure, the rats were euthanized and sampled. The left femur was used for measurement of bone mineral density (BMD). The right femur distal metaphysic cancellous bone was processed for morphological evaluation. Our results showed that the femur BMD in the 4-week OVX group was not significantly decreased compared with that of the 4-week Sham group, but that the volume of adipose tissue in the bone marrow was markedly increased. The femur BMD in the 8-week OVX group was decreased significantly compared with that of the 8-week Sham group ( P   <   0.05). Meanwhile, the volume of haematopoietic tissue decreased and the volume of adipose tissue increased. The number of megakaryocytes was decreased ( P   <   0.05). Interestingly, the osteoclasts and mast cells were increased in number in the 8-week OVX group ( P   <   0.05). These changes became obvious in the 12-week OVX rats, in contrast to the Sham groups. The volume of trabecular bone and the number of osteoblasts in the 12-week OVX group decreased significantly. Increased reticulin fibres were observed only in the 12-week OVX group. Our studies demonstrated a reciprocal correlation between bone-forming osteoblasts and marrow adipose tissue and suggest that OVX rats may be valuable as an animal model to study hypohaemopoiesis.     

脊椎植骨术中人工骨对软组织的反应

背景：脊椎后路植骨融合是常见的脊椎术式,人工骨可以很好地辅助植骨融合,但是由于软组织可能对人工骨存在一定的反应,人工骨目前很少应用于脊椎后路植骨中。 目的：拟通过兔的脊椎后路植骨实验,探讨如何降低脊椎手术中软组织对人工骨反应。 方法：36只成年公兔随机分为可吸收止血纱布组和对照组,于L2-3去皮质的椎板表面上,植入β-磷酸三钙人工骨,以可吸收止血纱布隔离背侧软组织为可吸收止血纱布组,无隔离物为对照组。检测植骨后不同时间点,兔血液中的C-反应蛋白表达,记录植骨后1周和12周皮肤愈合和皮下组织愈合情况以及局部炎症反应,CT检查记录植骨后不同时间点的人工骨爬行替代情况。 结果与结论：1周时,可吸收止血纱布组所有兔的背侧筋膜愈合完整;对照组9只中7只筋膜愈合完整,2只背侧筋膜愈合欠佳。12周时,可吸收止血纱布组9只中8只背侧筋膜愈合良好,1只愈合欠佳;对照组9只中6只愈合良好,2只愈合欠佳,1只轻度感染。1周时两组肌肉组织都存在一定充血,部分炎性细胞浸润,可吸收止血纱布组炎性细胞浸润较少,局部充血相对较少。12周时两组肌肉组织都存在一定的肉芽组织增生,可吸收止血纱布组炎性细胞浸润略少,对照组部分动物可见较明显的坏死组织。植骨后即刻,植骨后1周,4周时血液中的C-反应蛋白表达在两组间差异无显著性意义。植骨后12周时,CT检查显示靠近骨面的人工骨吸收明显,靠近软组织的人工骨无明显吸收,人工骨吸收情况在两组间无明显区别。结果提示,人工骨放置应尽量与植骨面多接触,这可促进人工骨尽早吸收,并降低软组织反应。减少人工骨和软组织接触,可以降低软组织对人工骨的反应。可吸收止血纱布的早期生物隔离和组织修复作用能一定程度减少组织对人工骨的反应。     

降钙素促进骨质疏松骨床中植入体的骨整合

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。     

Effect of the difference of bone turnover on peri-titanium implant osteogenesis in ovariectomized rats

High and low bone turnover situations, both of which are typically observed as postmenopausal and senile osteoporosis, were created by ovariectomy (OVX), and then an investigation of whether or not the difference of bone turnover affected peri-titanium (Ti) implant osteogenesis in rats was conducted. Female rats were divided into four groups. The experimental and control groups underwent OVX or sham operations at 15 or 27 weeks of age, as high or low bone turnover groups, respectively. Ti implants were inserted into the tibiae at 30 weeks, then fluorochromes were injected 10 or 20 days after the implantation for histometry. The implants were retained for 30 days and then ground sections were prepared. Afterward, the cortical bone growth rate, bone contact ratio (BCR) of the implant in both the cortical bone area and medullary canal area, and the average trabecular bone thickness around the implant were evaluated. Biochemical markers of bone turnover were also measured. Biochemical measurements indicated both increasing osteocalcin production in OVX rats and decreasing tartrate-resistant acid phosphatase activity in the low-turnover group. Histometrical measurements showed decreasing cortical growth and low BCR in the medullary canal of the low-turnover group. The high-turnover group demonstrated BCR as high as that of the control group. There was no significant difference in the average trabecular bone thickness around the implant among the groups. As a result, two types of osteoporotic situations were confirmed and it was shown that the difference of bone turnover was clearly due to the diverse osteogenesis around the Ti implant.     

Efficacy of bone marrow-derived stem cells in strengthening osteoporotic bone in a rabbit model

Osteoporosis might be due to defects in mesenchymal stem cells (MSCs) that lead to reduced proliferation and osteoblast differentiation. We hypothesized that transplantation of MSCs into sites at risk for developing osteoporotic bone could improve bone structure and biomechanics. The aim of this study was to establish an osteoporosis rabbit model by ovariectomy (OVX), characterize the autologous MSCs from the OVX rabbits, and transplant the autologous MSCs into the OVX rabbits. MSCs harvested from bone marrow of normal and OVX rabbits were culture expanded and differentiated in osteogenic medium. Phenotypes were evaluated by collagen I immunostaining, von Kossa staining, and quantitative assays of bone-specific alkaline phosphatase (B-ALP) and osteocalcin (OCN). MSCs were transfected with green fluorescence protein (GFP) and implanted in the gluteus muscle to trace their fate in vivo. Cultured autologous MSCs from OVX rabbits were constructed in calcium alginate gels and then transplanted in the distal femurs. At 4 and 8 weeks after implantation, histomorphometrical and biomechanical analyses were performed on the samples. MSCs from OVX rabbits displayed higher B-ALP activity, but had similar OCN levels as compared to those from sham rabbits. After 8 weeks of implantation, more bone apposition was found in the MSC-alginate-treated group. Histomorphometry indicated increased trabecular thickness. Histology also illustrated improved microstructures with newly formed osteoids and enhanced trabecular thickness. In addition, biomechanical testing revealed stronger stiffness in the MSC-alginate treatment group. Therefore, this study implies that transplantation of MSCs can help to strengthen osteoporotic bone in rabbits.     

不同软组织处理方式对支抗微种植钉-骨界面的组织学影响*

背景：目前关于采用切开牙龈和非切开牙龈两种方法植入微种植体的微种植钉-骨界面的组织学差异研究尚未见报道。 目的：观察采用不同软组织处理方式时支抗微种植钉骨结合率的差异,检测有无上皮植入的发生。 方法：成年雄性杂种犬6只,自攻型微种植钉48枚,选择犬的一侧上下颌骨作为实验组,采用非切开牙龈的方式植入自攻型微螺钉;另一侧为对照组,采用切开牙龈的方式植入,两组均使用镍钛拉簧即刻加载水平力200 g。于第12周时处死动物,取微种植钉周围骨块,观察支抗微种植钉与骨界面的骨结合率及是否有牙龈上皮植入。 结果与结论：两组微种植钉均形成一定骨结合。实验组微种植钉-骨界面可见较多的纤维结缔组织,对照组骨结合率高于实验组(P < 0.01)。两组均未检测到牙龈上皮植入。提示两种软组织处理方式下即刻加载微螺钉均可形成一定骨结合,获得临床稳定性;切开牙龈植入法可较非切开牙龈植入法获得更高的骨结合率,而非切开牙龈植入法操作更简便,两种方法发生植入性上皮性囊肿的可能性均很小。