脱矿人牙骨基质粒径大小对垂直骨增量效果的影响

目的:探究不同粒径大小的脱矿人牙骨基质材料对兔颅骨垂直骨增量效果的影响.方法:选择6只新西兰大白兔,每只兔颅骨制备3个9 mm环形裂隙并在其上方固定钛容器,容器内随机植入以下3组:A组脱矿人牙骨基质(0.25～0.5 mm);B组脱矿人牙骨基质(0.5～1 mm);C组空白对照组.植入后12周进行锥形束计算机断层摄影(Cone beam computed tomography,CBCT)检查和组织学观察分析.结果:CBCT结果显示A,B,C三组有明显新骨生成,新骨自基底骨垂直向上生长,脱矿人牙骨基质与兔颅骨结合稳定,垂直骨高度维持良好.组织学观察显示脱矿人牙骨基质和骨组织界面出现不同程度血管化及新生骨.A,B两组新骨形成率无显著差异(P>0.05).结论:粒径大小对于垂直骨增量的效果没有显著性影响,不同粒径大小的脱矿人牙骨基质在垂直骨增量手术中均显示出良好的骨传导性及骨诱导性.     

改良自攻性纯钛帽植入兔颅骨的动物模型研究

目的对传统的纯钛帽改良后植入兔颅骨,建立新的种植体表面处理研究的动物模型。方法运用数控机床对纯钛板进行机械加工,压制中空半球形钛帽,底部添加自攻性螺纹,顶部添加两个环形小孔。48个纯钛帽植入12只新西兰兔颅骨。选取观察时间点为2周、4周,6周。通过大体标本和牙科微型CT观察纯钛帽植入的稳定性,制作带金属不脱钙硬组织切片,观察纯钛帽植入兔颅骨的动物实验模型骨组织效应。结果手术过程中植入共48个纯钛帽,其中2个松动,松动率为4.17%;植入2、4、6周取材时,48个标本无松动,脱落。牙科微型CT结果显示,纯钛帽能够稳定在兔颅骨上。带金属不脱钙硬组织切片显示,新旧骨组织形成明显界限,周围骨组织长入纯钛帽底部的螺纹,嵌合良好。结论改良自攻性纯钛帽制作加工相对传统的钛帽工艺简单,稳定性良好,减少辅助固定装置,减少手术创伤,简化操作步骤,提高实验效率,可以用于研究种植体表面处理方式的动物模型。     

钛种植体表面早期成骨方式的动物模型研究

目的：研究适合用于观察钛种植体表面早期成骨方式的动物模型。方法对原有的种植体植入模式进行改进,使种植体植入动物体内的初始状态为种植体外螺纹贴于种植窝骨壁,种植体螺纹内部与周围骨壁保持一定距离。4只Beagle犬下颌骨延期植入20枚种植体,植入后2周和4周分别处死2只Beagle犬,对标本进行组织学观察。结果4只Beagle犬手术创口均达到一期愈合,未出现种植体松动。组织学观察可见种植体表面新骨生成,种植体周围骨壁新骨生成,可清楚地观察到新骨生成方向,可观察到接触成骨和距离成骨。结论本研究创建的动物模型可以清晰地观察钛种植体表面早期成骨的方式,也可客观地反映种植体表面性能对其表面早期成骨方式的影响。     

应用骨胶原结合帐篷技术行上颌后牙连续缺失垂直骨增量一例

垂直骨增量是口腔种植骨增量手术中最大的挑战之一。当骨缺损较大时，往往需要开辟第二术区进行块状自体骨移植，或应用钛网或钛增强支架联合使用颗粒状自体骨及骨替代材料，并发症发生率较高，手术创伤较大。本病例患者上颌后牙区连续多牙重度垂直骨缺损，使用骨胶原（Bio-OssCollagen）结合钛钉及可吸收胶原膜进行垂直骨增量，于骨增量后6个月获得了平均6.57mm的骨高度增加，满足了种植体植入需要，种植体周围骨组织在修复后随访过程中较为稳定。此术式骨增量效果可预期、操作简便、创伤较小，或可为临床垂直骨增量的术式选择提供参考。     

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目的 探讨重组人骨形成蛋白-2(rhBMP-2)与胶原膜靶向结合后在兔颅骨引导骨再生(GBR)模型中的成骨效应。方法 将20只普通级雌性健康新西兰大白兔随机分成2周组和6周组,每组10只。所有大白兔均制备颅骨GBR模型,在颅顶骨植入4个钛筒,分别盖rhBMP-2/CBD胶原膜(rhBMP-2/CBD胶原膜组)、rhBMP-2胶原膜(rhBMP-2胶原膜组)、胶原膜(胶原膜组)和不盖膜(空白组)。分别在2周和6周时处死各对应组的大白兔,取样制作硬组织切片和石蜡切片,染色后进行组织学观察。结果 2周时可见胶原膜阻挡了纤维组织的长入,4组钛筒上层均无新骨生成,其中rhBMP-2/CBD胶原膜组钛筒顶端毛细血管增生量明显较其余3组多。6周时可见rhBMP-2/CBD胶原膜组钛筒上层大量新骨生成,与来源于颅骨骨面的新骨界限明显,而其余3组钛筒顶端未见新骨生成。结论 rhBMP-2与胶原膜靶向结合可形成具有骨诱导性的胶原膜,缓释rh BMP-2使胶原膜下方大量新骨生成,表层成骨可阻止纤维组织的长入和防止植骨床的塌陷,使成骨速度加倍。     

环状自体骨在严重牙槽骨吸收同期种植中的应用

目的:探讨应用环状自体骨移植对严重牙槽骨吸收同期种植的骨增量手术方法。方法:9例重度牙槽骨吸收患者接受了环状自体骨移植,同期植入12枚种植体。结果:所有种植体均成功植入,初期稳定性好,全部Ⅰ期愈合,术后X线片显示骨愈合良好,垂直骨骨高度增量3.68-6.17mm。平均骨增量高度4.70mm。结论:环状自体骨用于严重牙槽嵴的吸收并同期植入种植体手术方法简单,周期短,疗效可靠,值得临床推广。     

重组人骨形成蛋白-2结合胶原膜在兔颅骨引导骨再生模型中的成骨效应研究

目的    探讨重组人骨形成蛋白-2（rhBMP-2）与胶原膜靶向结合后在兔颅骨引导骨再生（GBR）模型中的成骨效应。方法    将20只普通级雌性健康新西兰大白兔随机分成2周组和6周组,每组10只。所有大白兔均制备颅骨GBR模型,在颅顶骨植入4个钛筒,分别盖rhBMP-2/CBD胶原膜（rhBMP-2/CBD胶原膜组）、rhBMP-2胶原膜（rhBMP-2胶原膜组）、胶原膜（胶原膜组）和不盖膜（空白组）。分别在2周和6周时处死各对应组的大白兔,取样制作硬组织切片和石蜡切片,染色后进行组织学观察。结果    2周时可见胶原膜阻挡了纤维组织的长入,4组钛筒上层均无新骨生成,其中rhBMP-2/CBD胶原膜组钛筒顶端毛细血管增生量明显较其余3组多。6周时可见rhBMP-2/CBD胶原膜组钛筒上层大量新骨生成,与来源于颅骨骨面的新骨界限明显,而其余3组钛筒顶端未见新骨生成。结论    rhBMP-2与胶原膜靶向结合可形成具有骨诱导性的胶原膜,缓释rhBMP-2使胶原膜下方大量新骨生成,表层成骨可阻止纤维组织的长入和防止植骨床的塌陷,使成骨速度加倍。     

复合材料C/C-SiC及Ti植骨界面Caspase-3、Bcl-2、Bax表达比较研究

目的观察C/C-SiC复合材料对周围骨组织细胞凋亡情况的影响。方法选用8只日本大耳白兔,雄性,随机分为2组(每组4只)。将实验材料(C/C-SiC复合材料)和对照材料(Ti)各8枚植入兔子股骨内。3个月后,将带有实验材料和对照材料股骨标本脱钙、进行免疫组化(Caspase-3、Bax、Bcl-2)染色。观察植入材料周围骨组织细胞生长和凋亡的表达情况,并利用Imagepro Plus 6.0图像分析软件分析棕染细胞的灰度值。然后利用SPSS 17.0统计软件进行独立样本t检验分析结果。结果实验动物麻醉及手术效果较理想。植入材料与骨结合紧密、无松动,大部分植入材料表面有新生骨组织。光镜下观察,Caspase-3、Bcl-2、Bax免疫组化呈阳性反应骨细胞胞质及部分细胞膜棕褐色染色。C/C-SiC实验组棕褐色染色平均灰度值与纯钛对照组棕褐色染色平均灰度值相比无显著差别。结论 C/C-SiC复合材料植入兔股骨内术后3个月,材料周围骨细胞凋亡程度与纯钛材料无显著差别。     

骨代用品实验中兔股骨远端标准骨缺损模型的建立

目的探讨兔股骨远端标准骨缺损动物模型在骨代用品研究中应用的可行性及科学性,为组织工程研究理想动物模型提供新的思路。方法健康成年新西兰大白兔15只,双侧股骨远端制作直径6mm、深10mm骨缺损,随机分为2组。实验组12只,植入无机骨粉,分别于2、4、6、12周取材;空白对照组3只,不植入材料,于术后12周取材。行大体观察,放射学检查,兔股骨远端解剖学测量及组织学观察。结果动物模型稳定,未出现病理性骨折及术后感染。该模型可清楚显示骨代用品的成骨能力及降解特性;空白对照组骨缺损区边缘见少量新骨生成,未见骨连接形成。结论兔股骨远端干骺端骨缺损模型解剖部位固定,干骺线为术中重要参考标记;主要在松质骨区制作标准骨缺损,其空间是足够的;该动物模型可作为骨代用品用于大动物及临床前实验一种较理想的标准骨缺损模型。     

e-PTFE膜联合Bio-oss骨代材料在种植手术中引导骨再生的应用研究

目的：评价e-PTFE膜联合Bio-oss骨代材料在种植手术中引导骨再生的临床效果.方法：43例需要行引导骨再生的种植病例,随机分为实验组和对照组,实验组采用e-PTFE膜与Bio-oss骨代材料联合行骨再生,对照组仅采用Bio-oss骨代材料,12个月后检测比较两种手术方式水平向和垂直向骨增量的效果.结果：骨增量术后两组病例手术切口均甲级愈合,植骨厚度和植骨高度两组病例无统计学差异（P＞0.05）,而成骨厚度、成骨高度,水平向、垂直向骨生长效果两组间有统计学差异（P＜0.05）,实验组显著高于对照组.结论：联合应用e-PTFE钛加强膜和Bio-oss骨代材料在种植引导骨再生中能获得较大的水平向和垂直向的骨增量.     

Bone augmentation in rabbit calvariae: comparative study between Bio-Oss and a novel beta-TCP/DCPD granulate

AIM: In the present in vivo study, we compare the bone regeneration capacity of a novel brushite cement synthesized in our laboratory (DTG) with Bio-Oss using rabbits as an animal model. METHODS: The study was performed in a group of 14 adult New Zealand rabbits using the bone conduction model. Two titanium cylinders were fixed into perforated slits made on the parietal cortical bone of each rabbit. One cylinder was left empty (negative control) and the other was filled with either Bio-Oss or brushite set-cement granules (test cylinder). Four weeks after the intervention, the animals were sacrificed and biopsies were taken. The following parameters were analysed: bone tissue augmentation, bone mineral density and biomaterial resorption. The comparison of data between the different groups was performed using the Mann-Whitney test with a significance level of p<0.05. RESULTS: The mean bone mineral density and augmented mineral tissue inside the test cylinders were similar but higher than those of negative controls. Material resorption and bone tissue augmentation were significantly higher in the defects treated with the brushite-based set cement (p<0.05). CONCLUSIONS: Brushite cement granules were more resorbable and generated more bone tissue than Bio-Oss inside the titanium cylinders placed in the rabbit calvaria.     

Use of a Collagen Membrane Loaded With Recombinant Human Bone Morphogenetic Protein‐2 With Collagen‐Binding Domain for Vertical Guided Bone Regeneration

Background: Vertical bone regeneration of severe atrophic alveolar ridges remains a challenging procedure in implant dentistry. Methods: The aim of this study, accordingly, is to use a rabbit vertical guided bone regeneration model to evaluate whether using a collagen membrane (CM) loaded with small doses of recombinant human bone morphogenetic protein‐2 with collagen‐binding domain (rhBMP‐2/CBD) would enhance two‐way vertical bone regeneration. In each of eight rabbits, four titanium cylinders were screwed in perforated slits made into the external cortical bones of the calvaria. The following four treatment modalities were randomly allocated: 1) cylinders filled with mineralized bone matrix and covered with CM/rhBMP‐2/CBD; 2) cylinders filled with mineralized bone matrix and covered with CM/rhBMP‐2; 3) cylinders filled with mineralized bone matrix and covered with CM alone; or 4) cylinders filled with mineralized bone matrix without a membrane cover. Results: After 6 weeks, the new bones were examined by histologic analysis. Slender new bone trabeculae were observed in the superficial layer of the titanium cylinders covered with CM/rhBMP‐2/CBD, and higher degrees of bone were observed in this group compared with the other three groups. The average area fraction of newly formed bone was significantly more in the CM/rhBMP‐2/CBD group compared with the CM/rhBMP‐2, CM, or the no membrane control groups (all P <0.01). Conclusions: The present study demonstrates that CMs loaded with small doses of rhBMP‐2/CBD induce new bone formation not only from the surface of the native bone, but also from the superficial structures. The augmented new bone, therefore, is improved in both quantity and quality.     

Effect of bone block graft with rhBMP-2 on vertical bone augmentation

The effectiveness of vertical bone augmentation was evaluated in the cranial bone of 15 rabbits using a block of deproteinized bovine bone plus 10% porcine collagen (DBBB) and a cortico-cancellous human bone block (CHBB) with recombinant human bone morphogenetic protein-2 (rhBMP-2) in comparison with a guided bone regeneration (GBR) technique. The rabbits were divided into six groups: DBBB alone, DBBB/rhBMP-2, DBBB/membrane, CHBB alone, CHBB/rhBMP-2 and CHBB/membrane groups. After 12 weeks, the rabbits were killed. The CHBB groups showed higher values than the DBBB groups in terms of vertical height, the area of new bone fill and the maintained grafted area. In the CHBB groups, the CHBB/rhBMP-2 group revealed similar results to GBR. This animal study verifies that a CHBB with rhBMP-2 could be an alternative treatment option for vertical bone augmentation.     

Effect of solely applied platelet-rich plasma on osseous regeneration compared to Bio-Oss: a morphometric and densitometric study on rabbit calvaria

Background: The use of platelet‐rich plasma (PRP) in bone augmentation procedures is well documented; however, the exact benefit of this material is not yet established. Purpose: This study aimed to evaluate the benefits of using PRP, when only used, and compare it to Bio‐Oss® (Geistlich Biomaterials, Wolhusen, Switzerland) in vertical bone augmentation capacity. Materials and Methods: The study was performed in calvaria of eight adult female New Zealand rabbits using titanium bone conduction cylinder. Two titanium cylinders were fixed into perforated slits made on the parietal bone of each rabbit. On each rabbit, one chamber was grafted with Bio‐Oss, and the contralateral was filled with PRP. Animals were sacrificed 4 weeks after intervention and biopsies were taken. Densitometric, histological, and histomorphometric analyses were performed to evaluate bone mineral density, vertical bone augmentation, and remaining graft volume, respectively. Statistical analyses were performed with Mann–Whitney test, using a significance level of p < .05. Results: Densitometric and histomorphometric data analysis revealed that mean bone mineral densities and bone augmentation were significantly lower in the cylinders treated with PRP (p < .0001) 4 weeks after implantation. Conclusion: This study showed no beneficial effect of using PRP on osseous regeneration. In addition, it was emphasized that Bio‐Oss presents good osteoconductive properties by achieving suitable bone volume values.     

纯钛杯在引导骨再生动物实验中的应用研究

目的:探讨纯钛杯的制备方法以及在引导骨再生动物实验中的作用与优点。方法:制备钛杯,按分组装入不同骨代用品后定植于兔颅顶骨,术后2、4、6周取样,组织学切片观察。结果:钛杯提供了一个良好的引导骨再生屏障及环境,在显微镜下骨粉与新生骨有良好的分界,可以清晰观察到新生骨高度及密度,并可作量化对照分析。结论:钛杯的应用使引导骨再生动物实验更具可靠性、可比性,操作更为简便,可广泛应用于骨代用品动物实验研究并起到重要作用。     

Placement of autogeneic bone chips or bovine bone mineral in guided bone augmentation: a rabbit skull study

PURPOSE: Our primary aim was to use a rabbit guided bone augmentation model to evaluate whether use of autogeneic bone grafts or bovine bone mineral (BBM) combined with a space-making barrier enhances bone augmentation compared with a barrier alone. MATERIALS AND METHODS: Sixteen rabbits were studied. In each rabbit, 2 titanium cylinders, each with 1 titanium lid, were placed subcutaneously in perforated slits made in the cortical bones, with their open ends facing the parietal bones. One cylinder was left empty and the other was filled with either autogeneic skull bone chips or BBM. Bone labels were injected after 4 and 11 weeks. After 12 weeks, the animals were sacrificed to obtain ground sections for histology and histomorphometry. RESULTS: Significantly more tissue was augmented in the 2 test groups than in the control group. Most of the autografts were resorbed, leaving only minute amounts in the upper third of the cylinders. Slender new bone trabeculae were distributed mainly from the contiguous bone plate that had no contact with the remaining graft material. In the BBM group, most of the BBM remained evenly distributed in the cylinder. In the upper third of the cylinder, the BBM was surrounded by soft connective tissue, while in the lower two thirds, mainly mineralized bone enclosed the BBM. Equal amounts of mineralized bone were found in both test groups. Comparisons of contact between bone and BBM on one hand and bone and bone cylinder wall on the other revealed that the greatest bone contact was with the BBM in the lower third of the cylinder. In the middle and upper third of the cylinder, bone-BBM contact and bone-cylinder wall contact were similar. Fluorescent label intensity was higher in the autograft group than in the BBM group. In all 3 groups the intensity of the early label was similar to that of the late label, indicating that the graft materials do not seem to retard mineralization. DISCUSSION: BBM was found to promote as much new bone as did autogeneic bone. In addition, BBM appears to have at least the same osteoconductive properties as titanium, provided BBM is contained in a stable environment. CONCLUSIONS: Placement of autogeneic bone or BBM in conjunction with a stiff space-making barrier generated more tissue than a barrier only. In this model, autogeneic bone chips and BBM augmented similar amounts of new mineralized bone.     

Bone augmentation ability of autogenous bone graft particles with different sizes: a histological and micro-computed tomography study

Objectives: The purpose of this study was to investigate the augmentation process and ability of autogenous bone graft particles of two different sizes in a vertical augmentation chamber.
Material and methods: The cranial bones of 24 rabbits were used. Two polytetrafluoroethylene chambers were filled with harvested bone from tibia with small bone (SB; 150–400 μm) and large bone (LB; 1.0–2.0 mm) of the same weight. Animals were sacrificed after 1, 2, 4 and 8 weeks. The samples were analyzed by micro-computed tomography (micro-CT) for quantitative analysis, and embedded in polyester resin as non-decalcified specimens for histological analysis. Total bone volume (TBV), bone height (BH) and distribution of bone structure were calculated by micro-CT.
Results: Micro-CT evaluation and histology revealed a significant difference between the investigated specimens. TBV and BH of SB decreased to about 50% of the initial situation, and there was a statistically significant difference between 1 and 8 weeks. In contrast, TBV and BH of LB were almost retained at all experimental time points. Significant differences in TBV and BH were also observed between LB and SB at 8 weeks. Bone volume of SB decreased predominantly in the upper half of the chamber at 4 and 8 weeks. In the histological observations, SB showed favorable new bone formation and rapid bone resorption in a time-dependent manner during the entire experimental period. However, LB exhibited favorable morphological stability and continued new bone formation.  

Conclusion:

SB follows a smooth osteogenic process, whereas it is not effective in volume augmentation. LB is superior to SB in augmentation ability.     

Augmentation of intramembraneous bone beyond the skeletal envelope using an occlusive titanium barrier. An experimental study in the rabbit.

The aim of this investigation was to evaluate whether augmentation of intramembraneous bone beyond the skeletal envelope can be predictably achieved by placing a completely occlusive barrier on the skull bone of rabbits, hereby creating a secluded space with bone tissue being the only adjoining tissue. The experiment was carried out in 3 New Zealand white rabbits. In each animal, a midline incision was made down to the bone surface of the skull and a skin‐periosteal flap was raised to expose the skull bone on both sides of the midline. Two prefabricated titanium domes with an inner diameter of 4.5 mm and an inner height of 3.0 mm were installed on each side. The domes were supplied with a horizontal, peripheral flange and a vertical edge, fitting tightly into a circular slit, prepared by a trephine into the skull bone. This arrangement ensured a stable anchorage of the dome and a reliable peripheral sealing of the space. The skin‐periosteal flaps were relocated to cover the domes and sutured. After a healing period of 3 months, the animals were killed and the experimental areas excised and prepared for histological transversal ground sections with each dome in situ. The results demonstrated complete bone fill of all domes, with no signs of ingrowth of other types of tissues, indicating that the use of a barrier with total occlusiveness, sufficient stiffness and stability and reliable peripheral sealing will result in predictable bone augmentation of spaces also beyond the skeletal envelope.     

氟化物Y500R珊瑚骨羟基磷灰石复合人工骨在兔颅面成骨效应的实验研究

目的：探讨氟离子对珊瑚骨羟基磷灰石（coral hydroxyapatite,CHA）在兔颅面成骨效应中的影响,了解结合了氟离子后的珊瑚骨羟基磷灰石成骨效能的变化。方法制备含氟Y500R珊瑚骨羟基磷灰石的人工骨及纯钛金属帽,选用新西兰大白兔24只,分为含氟CHA组和CHA组,每组12只。含氟CHA组兔颅面安放并固定2个装有含氟Y500R珊瑚骨羟基磷灰石人工骨的钛帽,CHA组钛帽装入珊瑚骨羟基磷灰石,注射四环素及钙黄绿素荧光双标记物,分别于2、4、6周时各处死8只实验动物（每组4只）,样品处理后作大体标本,观察新骨形成高度和新生骨质荧光带面积,制作硬组织切片行甲苯胺蓝—碱性品红染色,进行组织学观察。结果术后大体标本观察、荧光显微镜观察、硬组织切片染色观察结果显示,术后含氟CHA组新生骨质明显多于CHA组,成骨效应活跃。不同时期新生骨质荧光面积差异具有统计学意义（F=6.36,P=0.019）,含氟CHA组明显多于CHA组（P<0.05）。结论低浓度（1.0×10?7 mol/L～5.0×10?5 mol/L）的氟离子能有效促进骨生成作用。     

Measurements of stability changes of titanium implants with exposed threads subjected to barrier membrane induced bone augmentation. An experimental study in the rabbit tibia.

The purpose of the present study was to evaluate in a rabbit model the changes in stability of implants that had been subjected to barrier membrane induced bone augmentation, as compared to untreated controls. One titanium implant was inserted in each proximal tibial metaphysis of 10 rabbits. The implants were placed in such a way that 4–5 threads on one side of the implant were left uncovered by bone. On the test side, the exposed implant surface was treated by means of a barrier membrane technique to provide for bone augmentation, while the contralateral side was untreated. The stability evaluations were made by means of resonance frequency measurements (RIM) at Day 0 and after 8, 16 and 24 weeks of healing. In addition, changes in the area of exposed implant threads were documented and measured on photographs. Removal torque measurements were performed at the day of sacrifice. In this study it was not possible to demonstrate a statistically significant better stability of implants subjected to barrier induced bone augmentation as compared to control implants still having exposed threads as evaluated by RIM and removal torque measurements.