骨髓基质成骨细胞-松质骨基质复合人工骨皮下移植成骨作用的实验研究

目的：观察骨髓基质成骨细胞－松质骨基质复合人工骨皮下移植的成骨作用，探索骨髓基质成骨细胞和松质骨基质分别作为骨组织工程种子细胞和支架材料的可行性。方法：成年新西兰兔骨髓细胞体外培养，诱导后，经混匀，接种，固化，形成骨髓基质成髓细胞－藻酸盐－松质骨基质复合人工骨，并植回取材兔背部皮下，对照组分别植入藻酸盐－松质骨基质复合物和松质骨基质，植入4，8周取材，行X线摄片，组织学检查和组织学定量分析，观察骨形成情况，结果：骨髓基质成骨细胞－藻酸盐－松质骨基质复合人工骨皮下成骨效果明显优于藻酸盐－松质骨基质复合物组和松质骨基质组，复合人工骨标本兼有膜内成骨和软成骨，以膜内成骨为主，对照组仅见不得软骨成骨，结论：采用组织工程方法形成的复合人工骨皮下成骨作用明显，骨髓基质成细胞和松质骨基质可以分别作为种子细胞和支架材料而用于组织工程骨的构建。     

松质骨基质-骨髓基质成骨细胞复合物的异位成骨作用

目的：观察松质骨基质－ 骨髓基质成骨细胞复合移植皮下成骨作用,以探索松质骨基质作为骨组织工程支架材料的可行性。方法：新生兔骨髓细胞体外培养、诱导后,接种于藻酸盐／松质骨基质中,形成松质骨基质／藻酸盐／骨髓基质成骨细胞复合物,并植入裸鼠背部皮下,对照组单纯植入松质骨基质。植入４、８ 周后行 Ｘ线摄片和组织学检查,观察骨形成情况。结果：松质骨基质／骨髓基质成骨细胞复合物皮下成骨效果明显优于松质骨基质。前者兼有纤维成骨和软骨成骨,以纤维成骨为主;后者仅见少量软骨成骨。结论：松质骨基质可以作为一种良好的骨组织工程支架材料。     

Fgf9在小鼠下颌骨发育软骨成骨及膜内成骨过程中的作用探讨

目的： 观察成纤维细胞生长因子9（fibroblast growth factor 9, Fgf9）基因敲除小鼠模型中下颌骨发育的骨质变化,探讨Fgf9参与下颌骨发育中的软骨成骨和膜内成骨的过程。方法： 建立Fgf9基因敲除小鼠模型（Fgf9^-/-）。利用显微CT技术检测Fgf9^-/-的下颌骨形态及骨参数,利用原位杂交对Fgf9在下颌骨的表达进行定位,应用H-E染色和番红固绿染色对胚胎的髁突、麦克尔软骨、膜内成骨区进行组织学分析。采用 SPSS 25.0软件包对数据进行统计学处理。结果： 显微CT显示,Fgf9^-/-髁突、喙突、下颌角区形态不佳,Tb.N降低、Tb.Sp增高、BMD下降。原位杂交显示,Fgf9广泛表达于软骨膜、软骨细胞、成骨细胞、血管内皮细胞及软骨及骨的周围间充质细胞。H-E染色与番红固绿染色显示, Fgf9^-/-髁突软骨形态畸形、软骨基质分泌不足、肥大软骨细胞比例下降、周围骨小梁纤细且分散。Fgf9^-/-麦克尔软骨前段软骨成骨及下颌骨体部的膜内成骨形成的骨小梁纤细、分散且矿化不良。结论： Fgf9在髁突软骨成骨过程中,促进软骨细胞分化成熟、分泌软骨基质,同时可能促进成骨细胞分泌骨基质,从而形成粗壮且健康的骨小梁。Fgf9参与膜内成骨,通过调控成骨细胞,促进骨小梁形成和矿化。     

鸵鸟骨转化多相钙磷陶瓷支架负载骨髓基质细胞异位成骨性能研究

目的：观察鸵鸟骨转化多相钙磷陶瓷复合骨髓基质细胞后植入裸鼠皮下的成骨性能。方法：获取兔髂骨松质骨骨髓基质细胞，体外分离、扩增、诱导后接种于多相钙磷陶瓷支架。支架／细胞复合物植入裸鼠背部皮下，单纯支架材料植入作为对照。植入后4周、8周取材，通过大体、组织学观察评价成骨活性。结果：支架／细胞复合物植入后4周，新骨主要以软骨为主，部分区域见少量成熟骨，可见软骨内成骨方式。植入后8周，材料表面和孔隙内有更多的成熟骨形成，部分区域有血管和多核巨细胞分布。结论：支架／细胞复合物显示良好的成骨活性，鸵鸟骨转化多相钙磷陶瓷可以用于骨组织工程支架材料。     

以藻酸钙为载体的可注射性组织工程骨研究

目的：研究藻酸钙／骨髓基质成骨细胞复合物在有免疫动物体内成骨的可行性。方法：从免筋骨中获取骨髓基质成骨细胞，将骨髓基质成骨细胞与25g／L藻酸钠溶胶混合形成藻酸钠／骨髓基质成骨细胞复合物，取其2ml与0．17g硫酸钙粉末混合均匀，注射于新西兰兔背部皮下，观察成骨情况。结果：藻酸钙／骨髓基质成骨细胞复合物植入免皮下四周后有类软骨样组织形成，8周时有骨小梁、骨髓腔等骨组织结构。结论：藻酸钙／骨髓基质成骨细胞复合物通过注射方式在有免疫动物体内可以形成骨组织。     

牛骨形成蛋白（bBMP）诱导成骨的酶组织化学研究

采用不同浓度尿素和盐酸胍从小牛骨基质中分离纯化出牛骨形成蛋白,将植入小鼠股部的肌肉内观察诱导成骨过程。组织学和酶组织化学研究表明,ｂＢＭＰ诱导间充质细胞逐渐分化形成软骨细胞和成骨细胞,最终新骨形成。诱导成骨的时间和过程与以往报道一致。     

促进口腔种植体骨整合因素研究进展

口腔种植体骨性结合是牙种植成功的标志，运用骨引导再生膜、骨基质明胶、骨形成蛋白、羟基磷灰石涂层、激素、高压氧、电磁场等用以诱导和促进种植体－骨界面骨的形成和生长，加速和改善骨结合，取得成效。     

内置式牵张成骨术与骨内牙种植体联合治疗火器伤性下颌骨缺损

目的:探讨内置式牵张成骨术与骨内牙种植体联合治疗火器伤性下颌骨缺损的临床应用可能性.方法:为1例火器伤性下颌骨缺损患者延期行内置式牵张成骨术,后期行骨内牙种植体植入和修复.术中常规截骨,制作骨转移盘,固定内置式骨牵张器,术后一周以每日1mm的速度行骨牵引,共牵引8mm.固定期大体,螺旋CT观察新骨生成及缺损修复状况.固...     

在移植骨上延期种植的实验研究

目的论证冷冻自体下颌骨复合髂骨移植后延期种植的可行性。方法16只成年雄性杂种狗，制备下颌骨双侧骨缺损，左侧行冷冻自体下颌骨骨块的原位再植并结合髂骨松质骨移植，即复合移植组（composite transplantation group，CTG），右侧缺损行自体髂骨块移植即髂骨移植组（iliac transplantation group，ITG），术后3个月分别在两类骨块上植入IMZ TPS种植体，种植体植入后3、6、9、12周分别处死4只动物取材，采用数字化X线片对种植体与颌骨结合界面进行灰度定量分析，组织学观察种植体．骨结合情况。结果各期种植体周围均未见吸收性骨质密度减低影像。骨一种植体界面灰度定量分析显示，种植体植入两类移植骨3、6和9周时，其界面骨质密度改变差别明显，复合移植组明显优于髂骨移植组；种植体植入12周时，两组界面骨质已无明显差别，两类移植骨均与种植体有良好的骨结合，其骨愈合方式基本相同。结论冷冻自体下颌骨复合移植修复下颌骨缺损并延期植入牙种植体后，二者可形成良好的骨结合。     

山羊乳牙牙髓细胞复合多孔磷酸钙骨水泥异位成骨研究

目的:观察山羊乳牙牙髓细胞(SGDs)与多孔磷酸钙骨水泥之间的生物相容性及其异位成骨能力。方法:流式细胞仪检测第1代SGDs的STRO-1表达情况;体外培养的第4代SGDs进行成骨诱导7d后,与多孔磷酸钙骨水泥复合培养,扫描电镜下观察SGDs黏附和生长情况;细胞材料复合物植入裸鼠皮下8周观察异位成骨能力。结果:SGDs与多孔磷酸钙骨水泥复合培养3d后,细胞与材料表面贴合,形态正常,可见细胞伸出伪足,分泌胞外基质;裸鼠体内植入8周后,HE染色显示骨样组织形成,免疫组化OC呈阳性表达。结论:SGDs可以向成骨细胞分化,并具有诱导成骨能力,与多孔磷酸钙骨水泥结合,可形成骨样组织。     

Implant–Bone Interface Stress Distribution in Immediately Loaded Implants of Different Diameters: A Three-Dimensional Finite Element Analysis

Purpose: To establish a 3D finite element model of a mandible with dental implants for immediate loading and to analyze stress distribution in bone around implants of different diameters. Materials and Methods: Three mandible models, embedded with thread implants (ITI, Straumann, Switzerland) with diameters of 3.3, 4.1, and 4.8 mm, respectively, were developed using CT scanning and self‐developed Universal Surgical Integration System software. The von Mises stress and strain of the implant–bone interface were calculated with the ANSYS software when implants were loaded with 150 N vertical or buccolingual forces. Results: When the implants were loaded with vertical force, the von Mises stress concentrated on the mesial and distal surfaces of cortical bone around the neck of implants, with peak values of 25.0, 17.6 and 11.6 MPa for 3.3, 4.1, and 4.8 mm diameters, respectively, while the maximum strains (5854, 4903, 4344 μ?) were located on the buccal cancellous bone around the implant bottom and threads of implants. The stress and strain were significantly lower (p < 0.05) with the increased diameter of implant. When the implants were loaded with buccolingual force, the peak von Mises stress values occurred on the buccal surface of cortical bone around the implant neck, with values of 131.1, 78.7, and 68.1 MPa for 3.3, 4.1, and 4.8 mm diameters, respectively, while the maximum strains occurred on the buccal surface of cancellous bone adjacent to the implant neck, with peak values of 14,218, 12,706, and 11,504 μm, respectively. The stress of the 4.1‐mm diameter implants was significantly lower (p < 0.05) than those of 3.3‐mm diameter implants, but not statistically different from that of the 4.8 mm implant. Conclusions: With an increase of implant diameter, stress and strain on the implant–bone interfaces significantly decreased, especially when the diameter increased from 3.3 to 4.1 mm. It appears that dental implants of 10 mm in length for immediate loading should be at least 4.1 mm in diameter, and uniaxial loading to dental implants should be avoided or minimized.     

Anchoring dental implant in tissue-engineered bone using composite scaffold: a preliminary study in nude mouse model.

PURPOSE: The purpose of this study was to fabricate a tissue-engineered bone graft anchoring dental implant with bone marrow stromal cell (bMSC) seeded coral-implant composite scaffold. MATERIALS AND METHODS: Titanium dental implants (3 mm in diameter) were inserted into the cylinder coral scaffolds (5 mm in diameter and 1 mm in wall thickness). bMSCs were isolated from iliac bone marrow of adult New Zealand White rabbits, induced by dexamethasone and seeded into the composite scaffold at the density of 2 x 10 8 /mL in 200 muL medium. Nine cell coral-implant complexes were incubated in vitro for 5 days. One complex was processed for scanning electronic microscopy. The other 8 complexes, together with 4 coral scaffold without cell acting as control, were implanted subcutaneously into nude mice back. At 1 and 2 months after implantation, 4 specimens from the experiment group and 2 specimens from the control group were harvested respectively. New bone restoration and new bone integration with dental implant were evaluated by gross inspection, manual handling test, radiographic examination, and histologic observation. RESULTS: Specimens harvested at 2 months after implantation were red and similar to native bone. Manual handling test showed that dental implants were fixed in the newly formed bone. Radiographic examination showed that most of the coral scaffold had been absorbed. Bone density x-ray shadow could be observed around the dental implant. Histologic examination showed that large amount of new bone formed around the dental implants and integrated well with the implants in some area. In the control group no bone formation was observed both macroscopically and microscopically. CONCLUSION: The results of the study suggested that the tissue-engineered bone of bMSCs seeded natural coral-implant composite scaffold is promising for dental implant anchoring, which has positive implication for clinical jaw reconstruction.     

紫外线处理微弧氧化种植体的早期成骨研究

目的研究C波段紫外线(ultraviolet C,UVC)处理的微弧氧化(micro-arc oxidation,MAO)纯钛种植体植入兔胫骨后的早期成骨方式。方法实验分2组,MAO组和UVC-MAO组。MAO组将医用纯钛种植体经微弧氧化处理后植入新西兰大白兔胫骨。UVC-MAO组将医用纯钛种植体经过微弧氧化处理后,用15 W UVC灭菌灯对钛种植体照射48 h,经过25.0 kGyγ射线消毒后植入新西兰大白兔胫骨。2周后取出胫骨,用锥形束CT观察种植体表面成骨情况;制作胫骨硬组织切片,并以亚甲基蓝-酸性品红染色,光学显微镜观察两组种植体的成骨方式。结果 MAO组可见靠近种植体骨环底端的为成骨细胞及软组织,无任何骨组织,骨环斜面有从周围成熟骨生长的骨组织及类骨质,但所有组织与种植体表面均有一定距离,而非密切接触材料表面。UVC-MAO组可见种植体骨环底端及骨环斜面表面紧密接触类骨质及成骨细胞,还有已经分化的新生骨组织;所有组织与种植体表面紧密接触,无间隔。结论紫外线处理微弧氧化后的种植体,更有利于成骨细胞粘附于种植体表面,形成新生骨质并紧密贴附于种植体表面,骨环周围成熟骨质同时向种植体生长,有利于种植体早期的接触成骨。     

磷酸钙钠/β-磷酸三钙陶瓷支架接种骨髓基质细胞成骨性能的研究

目的：观察磷酸钙钠／β-磷酸三钙(NaCaPO2/β-TCP)支架接种骨髓基质细胞后植入裸鼠皮下的成骨性能。方法：通过理化方法,将煅烧牛松质骨转化为NaCaPO2/β-TCP双相钙磷陶瓷。获取兔髂骨松质骨骨髓基质细胞,体外分离、扩增、诱导后,接种于NaCaPO2/β-TCP支架。将支架／细胞复合物植入裸鼠背部皮下,NaCaPO2/β-TCP陶瓷单纯植入作为对照。植入后4、8周取材,通过大体、组织学观察,评价成骨活性。结果：支架／细胞复合物植入后4周,材料表面见相对较成熟的骨组织,内部主要为软骨;植入后8周,大量骨小梁形成。可见骨髓腔、骨髓细胞及脂肪细胞,在支架材料和骨组织的邻接区域见成骨细胞及破骨细胞。可见软骨内成骨方式。结论：NaCaPO2/β-TCP支架接种骨髓基质细胞后显示良好的成骨活性,能够促进未成熟骨矿化,可以作为骨组织工程支架材料。     

种植体直径-长度比的三维有限元应力分析

目的:探讨直径与长度连续变化时选择种植体尺寸的方法。方法 :运用Pro/E和ANSYS软件建立不同长度(7¹6 mm)、不同直径(316 mm)、不同直径(3⁶ mm)的三维有限元模型,施加垂直荷载和侧向荷载,观察种植体位移峰值和骨组织VonMises应力峰值等评估指标。结果:垂直或侧向荷载作用下,随着直径和长度的增大,各评估指标均明显下降(60%6 mm)的三维有限元模型,施加垂直荷载和侧向荷载,观察种植体位移峰值和骨组织VonMises应力峰值等评估指标。结果:垂直或侧向荷载作用下,随着直径和长度的增大,各评估指标均明显下降(60%⁸0%),相关度分析显示,两种荷载下直径的影响均较大(约90%),长度的影响与荷载有关(垂直荷载:18%80%),相关度分析显示,两种荷载下直径的影响均较大(约90%),长度的影响与荷载有关(垂直荷载:18%⁶0%;侧向荷载:<7%)。直径-长度比兼顾种植体直径与长度,当确定皮质骨承载力及安全系数,便可由直径-长度关系曲线选择合适的种植体直径与长度。结论:种植体直径与长度均可明显影响种植体位移和骨组织应力峰值。本文介绍的直径长度比法可为临床医生选择、优化种植体提供一种新的思路。     

螺距对即刻负载种植体和周围骨组织影响的三维有限元研究

目的探讨在即刻种植负载条件下,种植体形成骨结合后,梯形螺纹螺距对种植体和周围骨组织的影响,为种植体结构的优化提供依据。方法运用计算机辅助设计j维建模软件Solidworks,建立螺距分别为0．6mm、0．7mm、0．8mm、1．0mm、1．2mm、1．3mm、1．4mm、1．6mm的圆柱状梯形螺纹种植体模型,再将其分别与利用CT扫描数据蓖建的下颌骨组织模型进行仿真结合,在即刻加载情况下且种植体形成骨结合后,分别施加垂直向和与种植体长轴成15°的颊舌向力150N。运用ANSYSWorkbench有限元分析软件进行模拟仿真分析,比较种植体和周围牙槽骨组织,随种植体螺距改变而引起的应力、应变的变化。结果即刻负载且种植体与骨结合完成后,垂直向加载,皮质骨在种植体螺距为0．8mm和1．0mm时,Von—Mise应力、应变均较小;松质骨在螺距为0．7mm、0．8mm、1．0mm时,Von—Mise应力、应变较小;种植体在螺距为1．6mm时应力最小为44．18MPa,螺距为0．8mm时应变最小为11．04μm。颊舌向加载,皮质骨在螺距为0．7mm、0．8mm时,Von-Mise应力、应变较小;松质骨在螺距为0．6mm、0．7mm、0．8mm时,Von—Mise应力、应变均较小;种植体在螺距为0．8mm时应力最小为188．23MPa,螺距为0．6mm时应变最小为23．69μm。结论对于圆柱状梯形螺纹种植体,螺距选取1．0mm、1．2mm、1．3mm或1．4mm时,在即刻负载情况下,当种植体与骨结合完成后,种植体-骨组织系统各主要零件的综合力学性能较好、形变较小,对骨的破坏小,有利于种植稳定性的提高。     

Three‐dimensional bone structure around hydroxyapatite and titanium implants in rabbits

Long-term support of dental implants requires adequate bone thickness in the area surrounding the implant. A three-dimensional examination, including calculations of percent bone-implant contact and percent bone volume, was conducted to clarify the bone structure around pure titanium (Ti) and dense hydroxyapatite (HA) implants. The implants were installed in the tibiae of rabbits, and the bone structure was examined after 2, 4, 6 and 8 weeks. The bone formation following implantation differed in the cortical bone and cancellous bone areas. In the cortical bone area, the percent bone-implant contact and percent bone volume were comparatively consistent for both Ti and HA implants during the observation period. In the cancellous bone area, both findings were influenced by the implantation period, and the chronological bone structure in the cancellous bone area also differed between Ti and HA implants. The percent bone-implant contact and percent bone volume in the Ti implant increased over 8 weeks, whereas the dense HA implant increased for the first 4 weeks and then decreased. The implant materials, Ti and HA, affected the bone remodeling in the cancellous bone area.     

种植体长度与直径对骨界面应力分布影响的三维有限元分析

目的　比较不同直径、长度的种植体对种植体-骨界面应力分布的影响。方法　按照种植体不同长度与直径,建立种植义齿的三维有限元模型。以美国3I种植体系统为参考,在Solidworks三维制图软件中绘制包含种植体、相应基台及牙冠的三维实体模型。种植体长度分别设为8、10、12、14 mm,直径分别设为3.5、4.0、4.5、5.0 mm,通过不同长度与直径交叉组合,共得到16种模型。对每个模型进行垂直向及斜向加载负荷,运用Ansys Workbench 13.0分析比较各模型受力后应力分布情况。结果　两种载荷下应力集中出现在种植体颈部皮质骨区和根尖松质骨区,随着种植体长度增加,根尖松质骨区应力集中缓慢下降;随着种植体直径的增大,根尖松质骨区应力集中明显减小。结论　在种植体长度与直径的选择中,直径与长度越大,种植体-骨界面的应力集中越小,但与长度相比,直径的影响更加显著。     

Adapted preparation technique for screw-type implants: explorative in vitro pilot study in a porcine bone model

Objective: The aim of this study was to quantify the effect of adapted preparation on the insertion torque of self‐tapping implants in cancellous bone. In adapted preparation, bone condensation – and thus, insertion torque – is controlled by changing the diameter of the drilling. Material and methods: After preparation of cancellous porcine vertebral bone with drills of 2.85, 3, 3.15 or 3.35 mm final diameters, Brånemark sytem^® Mk III implants (3.75 × 11.5 mm) were inserted in 141 sites. During implantation, the insertion torque was recorded. Prior to implant insertion, bone mineralization (bone mineral density (BMD)) was measured with dental quantative computed tomography. The BMD values measured at the implant position were correlated with insertion torque for varying bone condensation. Results: Based on the average torque recorded during implant insertion into the pre‐drilled canals with a diameter of 3 mm, torque increased by approximately 17% on reducing the diameter of the drill by 5% (to 2.85 mm). On increasing the diameter of the osteotomy to 3.15 mm (5%) or 3.35 mm (12%), torque values decreased by approximately 21% and 50%, respectively. Conclusion: The results demonstrate a correlation between primary stability (average insertion torque) and the diameter of the implant bed on using a screw‐shaped implant. Thus, using an individualized bone mineralization‐dependent drilling technique, optimized torque values could be achieved in all tested bone qualities with BMDs ranging from 330 to 500 mg/cm³. The results indicate that using a bone‐dependent drilling technique, higher torque values can also be achieved in poor bone using an individualized drilling resulting in higher bone condensation. As immediate function is dependent on primary stability (high insertion torque), this indicates that primary stability can be increased using a modified drilling technique in lesser mineralized bone.