活性胶原基纳米骨修复即刻种植体周围骨缺损的研究

目的:观察胶原基纳米骨(nHAC)及活性胶原基纳米骨(AnHAC)修复即刻钛种植体周围骨缺损的效果,为临床应用奠定理论依据。方法:犬下颌骨拔牙创区制造即刻种植体周围骨缺损,分别采用植入nHAC、AnHAC、自体牙槽松质骨及不植入任何材料4种不同方法修复种植体周骨缺损,术后6周、12周,采用X线摄片、骨密度测量及组织学检查,观察新骨形成情况和新骨与种植体的关系。结果:两组实验动物中,除空白对照组外,骨缺损区均愈合良好,未见种植体周围炎发生。1)nHAC组:术后6周已有新生骨小梁形成,术后12周修复骨缺损,种植体边缘可见较多新骨形成;2)AnHAC组:成骨过程较早,术后6周即有较多新生骨组织出现,术后12周新骨组织与宿主骨完全融合,并与种植体表面形成广泛的骨性结合。结论:nHAC具有良好的骨引导作用,可良好地修复种植体周骨缺损,复合rhBMP-2后效果更佳。临床上可根据具体情况选用修复即刻种植体周围骨缺损的方法。     

胶原与骨形成蛋白复合物促进大鼠下颌角缺损成骨作用的研究

目的：评价rhBMP-2／胶原复合物对大鼠下颌角缺损愈合的促进作用：方法：在大鼠双侧下颌角各制备一个直径4mm的骨缺损，一侧植入rhBMP-2／胶原复合物，另一侧植入单纯胶原，分别于术后2、4及8周处死动物，行X线检查及制作脱钙石蜡切片进行组织形态计量学分析，评价骨愈合情况。结果：植入rhBMP-2／胶原复合物的骨缺损成骨面积百分比及新生骨面积均明显高于植入胶原的骨缺损：术后两周，实验侧骨缺损已基本为骨桥所连接，术后8周，骨缺损已完全骨性愈合对照缺损术后8周仍基本保持原状。结论：rhBMP-2服原复合物具有较强的成骨作用，可加速大鼠下颌角骨缺损的愈合     

骨形态蛋白复合物联合引导组织再生技术修复牙周骨缺损的实验研究

目的评价骨形态蛋白复合物联合引导组织再生技术修复牙周骨缺损的效果。方法选择6只新西兰兔，制备下前牙牙周骨缺损模型，将其分为3组：GTR组(牙周骨缺损处植入胶原膜)、BMP组(牙周骨缺损处植入骨形态蛋白复合物和胶原膜)和OFD组(牙周骨缺损处未植入任何物，对照组)。术后12周分别观察各组缺损处的组织学变化。结果BMP组骨缺损处只见少量的软组织，新生骨组织的量及其成熟程度明显优于GTR组和OFD组，显示骨组织修复良好。结论骨形态蛋白复合物联合GTR技术修复牙周骨缺损，与传统的GTR术和牙周翻瓣术相比，更能有效促进牙周骨组织再生与修复。     

rhBMP-2、胶原、珊瑚复合人工骨植入智齿牙槽窝的临床研究

目的：研究重组人骨形成蛋白（rhBMP-2)，胶原，珊瑚复合人工骨在修复口腔颌面部骨缺损和整复颌面畸形的作用。方法：将rhBMP-2，胶原，珊瑚复合人工骨植入阻生智齿拔除后的牙槽窝内，并设单纯珊瑚和空白对照组，术后进行临床和X线检查，记录邻近的第二磨牙远中牙槽嵴的高度。结果：术后12周复合骨组牙槽窝骨缺损和牙槽嵴高度均得到良好的恢复。珊瑚骨组得到较好的恢复，而空白对照组结果不明显，结论：rhBMP-2胶原，珊瑚复合人工骨植入智齿牙槽窝可较好地修复牙槽窝骨缺损及邻近的第二磨牙远中牙槽骨缺损。     

胶原基骨在慢性牙周炎骨修复中的临床疗效观察

目的观察、评价胶原基骨材料修复牙周骨组织缺损的临床有效性和安全性。方法采用随机、双盲的方式将牙周手术患者分为2组,A组使用胶原基骨材料,B组使用瑞福纳米人工骨进行牙周植骨术,观察患者术前及术后3、6个月时牙周探诊深度、临床附着丧失、龈沟出血指数和松动度的改变及骨组织愈合情况。结果使用胶原基骨和纳米人工骨进行牙周手术后,均可明显改善患牙的牙周探诊深度、附着丧失、龈沟出血指数和松动度,与术前差异具有统计学意义(P<0.01);2种骨组织替代材料对术后临床指标的改变无统计学差异(P>0.05)。结论应用胶原基骨材料可以改善牙周临床指标,其在牙周骨组织修复中具有有效性和安全性。     

rhBMP-2在种植体周围骨缺损修复中应用的组织学观察

目的:研究rhBMP-2及不同载体在种植体周围骨缺损修复中的应用。方法:在beagle犬下颌骨植入种植体,颊侧形成裂开性骨缺损,置入复合了不同浓度rhBMP-2的珊瑚羟基磷灰石人造骨(CHA)或可吸收胶原海绵(ACS)。种植体植入后2、4、8、12周,获取含种植体骨标本,进行组织学观察。结果:2周时,rhBMP-2组可见极少量的新生骨组织。4周时,rhBMP-2/ACS组新骨组织由牙槽骨顶端向缺损区中心方向生长;rhBMP-2/CHA组人造骨颗粒内部和周围出现呈岛状生长的新生骨组织。8周时,rhBMP-2/ACS组的新骨形成大片状结构;rhBMP-2/CHA组人造骨颗粒周围较多骨岛形成。12周时,rhBMP-2组的缺损区内骨量和骨高度进一步增加,与种植体形成骨性结合。浓度为0.05 mg/ml和0.2 mg/ml,载体为CHA或ACS促进骨再生作用差异无统计学意义。结论:以CHA或ACS为载体rhBMP-2能促进种植体周围骨缺损区内的骨组织再生并与种植体表面较好地结合。     

应用生长因子-支架构建方式的组织工程方法再生牙周组织的实验研究

目的：观察评价生长因子-支架构建方式的组织工程方法对牙周组织再生修复的影响和意义，探讨纳米羟基磷灰石材料(nHAC)和重组人骨形成蛋白-2(rhBMP-2)用于牙周组织工程的可行性。方法：将rhBMP-2与nHAC复合植入动物人工牙周组织缺损，表面覆盖聚四氟乙烯(e-PTFE)膜，以卒白对照组和单纯GTR组作为对照。术后8周进行组织学观察和测量，分析评价其牙周组织的再生情况。结果：rhBMP-2-nHAC-膜复合植入组较空白对照组和单纯GTR组有更多的新生牙槽骨、新生牙周膜和新生牙骨质生成，且未见上皮长入。结论：应用生长因子-支架构建方式的牙周组织工程方法能更有效地促进牙周组织再生和重建，而rhBMP-2和nHAC有望用作牙周组织工程的生长因子和支架材料。     

应用放射性核素骨显像观察组织工程化骨修复兔下颌骨缺损的能力

目的:应用99mTc-MDP放射性骨显像观察复合兔骨髓基质细胞的纳米羟基磷灰石/胶原(BMSCs nHAC)修复兔下颌骨缺损的能力。方法:兔下颌骨体部范围为15mm×15mm的全层骨缺损分别采取相应方法修复:A组,BMSCs nHAC修复;B组,nHAC修复;C组,空白对照组,缺损不做修复。术后4、8、12周分别通过放射性核素骨显像进行监测。结果:术后4周,A组核素浓聚程度明显高于B组、C组,差异具有统计学意义,B组核素浓聚程度亦高于C组,差异具有统计学意义;术后8周,A组核素浓聚程度明显高于B组、C组,差异具有统计学意义,B组核素浓聚程度与C组无显著差异;术后12周,3组核素浓聚程度无显著性差异。结论:BMSCs nHAC修复下颌骨缺损与单独使用nHAC相比具有较好的成骨能力和血管化程度。     

组织工程骨修复颅骨极限缺损种子细胞归宿的探讨

目的：检测纳米羟基磷灰石复合胶原／聚乳酸材料（nHAC／PLA，nano-hydroxyapatite／collagen／Polyacticacid）与骨髓基质细胞（BMSCs，bone marrow stroma cells）在体外复合构建的组织工程骨修复兔颅骨极限缺损的能力，并探讨种子细胞的归宿。方法：将圆盘状nHAC／PLA与BrdU标记的自体BMSCs复合后，植入新西兰大白兔颅骨直径1．5cm全层缺损中。设自体髂骨组、空白对照组及nHAC／PLA组，术后8w、16w通过X线片、HE染色、Masson’s三色法染色、荧光组织学和免疫组织化学染色，观察比较颅骨缺损的修复情况及种子细胞的归宿。结果：nHAC／PLA＋自体BMSCs组修复颅骨缺损的能力强，与自体髂骨组类似，nHAC／PLA组材料修复骨缺损的能力较弱，但强于空白对照组，组织工程骨的成骨细胞由植入的种子细胞演化而来。结论：nHAC／PLA复合自体BMSCs具有良好的修复骨缺损能力。     

新型骨支架材料复合物修复兔下颌骨缺损的实验研究

目的研究纳米羟基磷灰石／胶原／聚乳酸／富血小板血浆复合物（nHAC／PLA／PRP）在骨缺损修复过程中的成骨作用。方法制备兔下颌骨10mm×8mm贯穿性缺损．按不添加材料A组、单纯材料（nHAC／PLA）B组、活性材料（nHAC／PLA／PRP）C组加入相应材料．术后2、4、8、12周处死动物,分别从大体、影像学、扫描电镜、组织学方面进行观察．计量新骨面积并进行方差分析。结果影像学观察B、C组2、4、8、12周缺损区密度均高于A组。B、C组之间差异无统计学意义。电镜观察3个组边界区主要由纤维组织包绕．B组边界区可见少量新生骨散在分布．C组纤维组织更致密,可见少量新骨片状分布;组织学观察可见B、C组各时间点骨缺损区新骨形成均优于A组．C组新生骨及新生血管的量较B组多。随着时间延长,各组新骨均有增多．残留的材料减少．有大量骨样组织长人活性材料,骨成熟度增高,残留材料逐渐被活跃生长的骨组织包围并替代。以方差分析对组间新骨面积进行两两比较,结果显示第2、4周两两组间差异有统计学意义．8、12周时A组与B、C组间差异有统计学意义．后两组之间差异无统计学意义。结论由nHAC／PLA和富血小板血浆（PRP）构建的复合材料具有良好的生物相容性、骨传导及骨诱导活性．有望应用于临床修复骨缺损。     

Relationship between bone mineral density and bone stiffness in bone fracture

Objectives Using cancellous bone blocks of racehorses, the relationship between bone mineral density (BMD), which indicates bone strength, and stiffness in bone fracture occurrences was studied.Methods Two groups of cancellous bone blocks were prepared: a fractured group, using the first phalangeal bones of seven racehorses with sagittal fractures; and a nonfractured group, using the first phalangeal bones of nine autopsied racehorses without any fractures. By a peripheral quantitative computed tomography scan, the BMD values were shown as color images and evaluated. In addition, the BMD values obtained from the fractured and nonfractured groups were compared with the stiffness values obtained from a compression test.Results The difference between the average BMD values of the fractured and nonfractured groups was easily observed on the BMD color-conversion display image. The average BMD of the fractured group (472.1 mg/cm³) was significantly higher than that of the nonfractured group (284.5 mg/cm³, P = 0.005). Moreover, the average stiffness of the fractured group (5564.5 N/cm) was significantly higher than that of the nonfractured group (3808.6 N/cm, P = 0.008).Conclusion These results suggest that the occurrence of a fracture does not depend on the BMD or the bone stiffness value.     

Aneurysmal bone cyst of the zygomatic bone

Aneurysmal bone cysts are a rare finding in the facial bones and jaws. Only one previous case of this entity affecting the malar bone could be found in the literature. Ultrasound and isotope scan features of this entity are described.     

Aneurysmal bone cyst of the sphenoid bone

Aneurysmal bone cyst (ABC) is an uncommon benign lesion that rarely presents in the craniofacial region. Aneurysmal bone cysts represent nearly 1.4% of all bone tumors, and among those, only 3% are located in the cranium. In this study, we report on an ABC located in the sphenoid bone with superior nasal cavity and ethmoid extension. The presenting symptom of our patient was headache, followed by diplopia, loss of visual accuracy, and abduction restriction. We successfully resected the lesion by a combined subcranial-midfacial degloving approach without any complications or recurrence.     

Particulated bone grafts--effectiveness of bone cell supply

OBJECTIVE: The objective of this study was to measure the amount of viable bone cells present in different types of bone graft. MATERIAL AND METHODS: Bone chips were harvested from the trabecular or cortical bone of the mandible or the iliac crest and either milled or not. The average size of unmilled bone particles was 5 x 5 x 5 mm and that of milled was 2 x 2 x 2 mm. Drill sludge was obtained using either a ball reamer, a diamond ball or an implant drill (the latter from mandibular bone and of average dimension 1 x 1 x 1 mm). A measure of 0.5 g of each category was cultured in Dulbecco's modified Eagle's medium with additives for four weeks. Cell counts were performed. An analysis of the osteocalcin synthesis, the alkaline phosphatase (ALP) activity, the collagen types and the concentration of bone-specific collagen cross-links in medium supernatants was performed. RESULTS: Cells stained positively for osteocalcin and ALP in all groups. Bone-specific collagen cross-links could be quantified and collagen of types I and V was present with no difference in all groups. Unmilled spongy bone chips revealed greater cell counts than milled (P<0.05). Spongy bone chips revealed greater cell counts than cortical bone chips (P<0.05). Drill sludge obtained by hard alloy ball reamer showed the least amount of viable cells (P<0.05). CONCLUSIONS: Bone milling reduces the quantity of osteoblasts. Bone obtained by the ball reamer supplies a smaller number of cells than bone obtained by other methods. Unmilled spongy bone chips appear to offer the greatest amount of viable osteoblasts.     

Oncological treatment of bone tumours and bone metastases

The majority of patients with a malignant bone lesion will have bone metastases from a distant primary tumour. This could be apparent at diagnosis or develop later in the course of the disease. Some primary tumour types are more likely than others to develop bone secondaries. This common clinical problem requires a multidisciplinary approach in order to reduce patient suffering and maintain quality of life. Almost all patients with metastatic bone disease will have incurable cancer and this needs to be acknowledged when considering treatment options. Conversely primary malignant bone tumours are relatively rare conditions and thus need to be managed by specialist centres. Multimodality, multiprofessional treatment is required which may last for many months and can be associated with considerable toxicity. Patients with localized disease can be cured but there remains a high risk of both local recurrence and metastases.     

The effcct of eel bone powder on bone mineral density in mouse femoral bone

Improvement in bone mineral density (BMD) in the femur after administration of eel bone powder (EBP) was evaluated in ovariectomized (OVX) mice. Female ICR mice were given ovariectomies or sham operations at 9 weeks of age, then housed for 2 weeks during which they were allowed free access to a normal diet. Subsequently, the mice were divided into 3 groups: sham-operated mice fed a normal diet, OVX mice fed a normal diet, and OVX mice fed a diet containing EBP. After the mice in these 3 groups had been housed for 2 months (during which time they were allowed free access to their respective diets), they were dissected and analyzed. The BMD values in the removed femurs were measured by peripheral quantitative computed tomography (pQCT). Femoral total and femoral cancellous BMD values were higher in the EBP-treated group than in the nontreated group. Total BMD: the value in the EBP-treated group was 573 mg/cm³, and that in the non-treated group was 451 mg/cm³ (p<0.05). Cancellous BMD: the value in the EBP-treated group was 242 mg/cm³, and that in the non-treated group was 143 mg/cm³ (p<0.05). However, cortical BMD values did not significantly differ between the EBP-treated group and the non-treated group. Cortical BMD: The value in the EBP-treated group was 1891 mg/cm³, and that in the non-treated group was 1900 mg/cm³. pQCT was used to measure the cortical and cancellous BMD in the long bones. By use of a color conversion technique to display BMD, regional changes in the long bones can be expressed and easily measured. It has been well documented that EBP is effective for improvement or prevention of BMD reduction associated with OVX.     

Microscopy of bone cells, bone tissue, and bone healing around implants.

Newer methods of scanning microscopy using both light and electrons are particularly relevant to the study of bone cells, bone matrix organization, matrix mineralization, bone modeling and remodeling, and the adaptation of cells and matrix to implants. Most of such studies are conducted on retrieved implants, at least after the death of the related tissue. Because the retention of the tissue-implant relationship in such preserved tissue is crucial for critical evaluation of the implant, methods based on the study of flat surfaces of embedded tissue blocks are very important. Using electrons, the backscattered electrons in a scanning electron microscope can be employed to evaluate mean atomic number (density) and cathodoluminescence can identify polymers and fluorescent labels. Using light, confocal microscopical techniques permit the examination of layers deep to the block face. Confocal reflected and fluorescence methods allow the study of cell behavior upon both transparent and opaque substrates in the laboratory. Examples of the above are presented and interpretation problems discussed. Current experiments are aimed at enabling the study of bone wound healing and bone adaptation to implanted materials in vivo, through the implantation of optical quality windows and/or newly conceived and designed microscopical objective lenses.