锶磷灰石修复下颌骨缺损的实验研究

目的　用不同浓度的锶磷灰石 (Sr-HAP)植入动物体内 ,观察该材料的生物学反应 ,为其临床应用作前期研究。方法　将 2 4只新西兰大白兔分为 3组 ,双侧下颌角均造成 6mm× 12mm× 4mm的缺损 ,用不同浓度 ( 10 % ,5 % ,0 % )的含锶羟磷灰石块分别予以修复 ,术后 1月 ,3月 ,6月时随机处死一组分别进行尸解、四环素荧光标记、定量组织学观察以评估其生物性能。结果　锶磷灰石复合人工骨未引起感染和排斥反应 ,术后材料降解早 ,新生骨大量进入材料间隙 ,其成骨量明显较纯羟基磷灰石为多 ,且统计学上有差异 ,5 %的锶磷灰石烧结体内新生骨成熟度较 10 %者为高 ,但统计学上未显示出成骨量的差异 ,术后 3月时锶磷灰石周边出现强而亮的黄色荧光环 ,术后 6月时荧光环仍未消退。结论　 ( 1)锶磷灰石有良好的组织相容性、骨引导性及生物降解性 ,并具有一定程度的骨诱导性。 ( 2 )锶元素浓度并非是影响总成骨量的关键因素 ,总成骨量可能主要与生物降解的程度大小有关。 ( 3)锶的存在不但提高了新骨的总生成量 ,而且延长了新骨生成的总体时间和高峰期     

锶磷灰石在即刻种植骨缺损修复中应用的动物实验研究

目的:研究5%锶磷灰石(strontium substituted hydroxyapatite,Sr-HAP)在即刻种植时对骨缺损修复的生物学特性。方法:将6只犬随机分3组,拔除其下颌左右侧第2、4前磨牙,在其近中根牙槽窝处制备种植床,即刻植入种植体,同时在种植体远中颈部牙槽骨处造成3mm×3mm×5mm大小的骨缺损(右侧为实验组,左侧为对照组),实验组骨缺损处填入5%的锶磷灰石,对照组骨缺损处不放置任何材料。分别于术后1、2、3个月各处死2只犬,行大体观察、X线片、光镜观察。结果:动物对锶磷灰石几乎不产生炎症和排斥反应。术后1个月,X线片显示植入材料呈阻射影,有新骨生成,但骨质密度较低;光镜下可见种植体颈部远中加锶磷灰石处,材料颗粒稍有降解,降解处被紫色的新生骨所占据,颗粒内可见新生骨基质,种植体周围未见炎性细胞浸润。术后3个月,X线片显示种植体周围骨质密度更高,实验侧牙槽嵴顶比对照侧高而丰满;光镜下可见植入材料颗粒已基本和新生骨融合在一起,材料颗粒已降解得很小,被大量紫蓝色的新生骨所包绕。结论:5%的锶磷灰石具有良好的组织相容性、骨引导性及生物降解性;5%锶磷灰石在早期对于引导新生骨生成及维持骨量有一定的作用,是骨缺损,尤其是即刻种植时骨缺损修复的较好生物材料。     

锶磷灰石烧结体修复颌骨缺损的实验研究

目的　用不同比例的元素锶 (Sr)替代羟磷灰石 (HA)中的部分钙元素 ,通过动物实验研究该种复合人工骨在颌骨缺损修复中的应用。方法　将 32只新西兰大白兔 (简称新白 )分为 4组 ,在兔的下颌角造成约 2 m m×12 mm× 4mm的缺损 ,用不同浓度 (10 % ,5 % ,0 % )的含锶 HA块分别予以修复 ,于 2周 ,1月 ,3月 ,6月时随机处死一组进行尸解、组织学、扫描电镜观察以评价其骨修复能力。结果　掺锶羟基磷灰石复合人工骨几乎不引起排斥反应 ,术后早期即随材料的降解 ,新生骨引导进入降解间隙 ,并逐渐诱导未分化细胞转化为成骨细胞 ,随时间延长其成骨量明显较纯羟基磷灰石组为多 ,同时发现 5 %的锶磷灰石烧结体其成骨能力较 10 %者好。结论　掺锶羟基磷灰石较纯羟基磷灰石有更好的组织相容性、骨引导能力及生物降解率 ,并可能具备一定程度的骨诱导能力 ;掺锶羟基磷灰石的骨形成能力与其浓度并不成正相关。     

锶磷灰石生物特性的初步研究

目的:锶磷灰石是一种新型的磷灰石类陶瓷,本研究通过动物试验初步探讨其在生物体内的一些特性,为临床的广泛应用提供理论基础。方法:24只新西兰大白兔分为3组,双侧下颌角均造成约6 mm@12 mm@4 mm的缺损,用不同浓度(10%,5%,0)的锶磷灰石修复,术后1月,3月,6月时随机处死1组进行大体观察、X线摄片、组织病理、核素扫描(发射计算机断层术分析),评价其生物学性能。结果:锶磷灰石复合人工骨所致感染和排斥反应均较轻,组织切片上反映随材料的降解,新生骨大量长入现象比羟磷灰石更为明显,且周边软组织内有部分成骨现象,X线片上显示随时间的延长,材料和骨之间的密合度逐渐增加,6月时已几乎融为一体,同时锶磷灰石修复侧较羟磷灰石修复侧核素浓聚现象有明显的差异。结论:锶磷灰石有良好的组织相容性、骨引导性及生物降解性,能提高新骨生成量,具有更好的骨缺损修复效果,并可能有一定程度的骨诱导性。     

无机牛骨结合可吸收性胶原膜修复种植牙骨缺损的定量分析

目的 :评价无机牛骨 (deproteinizedbovinebonemineral,Bio -oss)与可吸收性胶原膜 (bioresorbablecollagenmembrane ,Bio -gide)在种植牙骨缺损中的引导骨再生作用。方法 :在 30只兔子股骨植入羟基磷灰石涂层BLB种植体 (3.3mm× 8mm) ,然后在其侧壁制造标准骨缺损 (4mm× 3mm× 3mm) ,骨缺损内植入Bio -oss,并在其表面覆盖Bio-gide膜 ,分别于术后 1、4、6个月取样本 ,制备带种植体的硬组织切片 ,通过计算机组织图像分析系统定性与定量分析。结果 :术后 1个月Bio -oss颗粒表面有新骨形成 ,随时间延长 ,新生骨量增加 ,Bio -oss百分率下降 ,6个月时新生骨百分率达 37% ,而Bio -oss百分率由 35 %下降到 2 5 % (P <0 .0 5 )。结论 :Bio -Oss结合可吸收性胶原膜使牙种植中的骨缺损获得重建 ,Bio-Oss是一种骨引导材料 ,引导骨组织再生并逐渐被新生骨所取代     

自体骨移植与生物材料修复下颌骨缺损的比较

目的：用组织学观察的方法及分析植入材料在成骨过程中的骨动力学变化比较自体骨移植和胶原羟基磷灰石植入修复下颌骨缺损的效果。方法：本实验将自体骨、胶原羟基磷灰石分别植入10头中国试验用小型猪下颌骨缺损内，采用常规组织学观察，测量并统计基本的骨动力学参数，从定量、动态的角度，研究分析各自在修复过程中骨生长情况。结果：胶原羟基磷灰石植入后比自体骨植入后骨再建发生早，说明前者也具有良好的成骨作用，可较早地促进新生骨生长。结论：胶原羟基磷灰石、自体骨修复下颌骨缺损，其前者可以免除患者自体二处手术供骨的痛苦及心理负担，优于自体骨移植修复，便于临床推广、应用。     

人牙龈成纤维细胞对羟基磷灰石人工骨附着情况的体外实验研究

本实验采用人牙龈成纤维细胞体外培养的实验方法及扫描电镜观察,探讨新型人工骨材料—羟基磷灰石在植入并修复牙周病所致骨缺损后能否成为牙龈附着的基础,使牙龈结缔组织生长并牢固附着其表面,进而诱导新骨形成,为临床应用修复治疗牙周骨缺损、重建牙龈新附着提供依据。结果表明人牙龈成纤维细胞与羟基磷灰石附着生长情况良好,羟基磷灰石是一种具有良好组织生物相容性能的人工骨材料、用于牙周骨缺损的治疗,将有广阔发展前景。     

生物陶瓷骨种植及其与骨组织结合机理的探讨

一种新型的磷灰石类生物陶瓷锶磷灰石植入动物体内骨后，采用扫描电镜、能量散射电子探针和Ｘ线能谱等先进的分析学、组织学方法对植入材料与骨组织界面作早期观察，并探讨了该材料与骨组织结合的机理。实验结果表明锶磷灰石骨种植早期就发生Ｓｒ元素的迁移，它与骨结合的机理是由于早期的表面降解作用促进了骨重建。其研究结果提示了锶磷灰石陶瓷是具有良好生物相容性和表面活性的骨组织替代材料。     

NPHA/BMP复合物在盖髓治疗中的动物实验及临床应用

目的　寻找一种在牙髓病治疗中能保存活髓的理想的盖髓剂。方法　采用天然型网孔羟基磷灰石 (NPHA) ,与骨形成蛋白 (BMP)组成NPHA/BMP复合物。动物实验 :以该复合物进行家兔肌内植入实验 ,以及羟基磷灰石 (HA)、NPHA分别植入家兔胫骨内的成骨效应实验。临床观察 :选择口腔门诊患者随机分为实验组 [用NPHA/BMP]10 0例 ,10 4颗牙 ;对照组 [用Ca(OH) 2 ]6 0例 ,6 0颗牙 ,分别进行盖髓治疗。结果　动物实验组织学观察证实 :NPHA植入肌肉未见诱导幼稚间充质细胞的增殖、分化以及成骨作用 ,生物相容性良好。NPHA/BMP复合物植入肌肉内 ,见明显新生骨形成 ,新生骨成长活跃且与材料呈直接界面 ,NPHA植入胫骨内观察无免疫排斥反应 ,其成骨量多于致密性羟基磷灰石。临床观察 1年随访结果 :NPHA/BMP复合物的盖髓成功率优于氢氧化钙。结论　NPHA/BMP复合物 ,生物相容性良好 ,具有传导和诱导成骨功能 ,是较理想的盖髓剂。     

骨髓基质干细胞与不同支架材料复合异位成骨能力的实验研究

目的:研究骨髓基质干细胞(bone marrow stromal cells,BMSCs)与不同支架材料复合后的异位成骨能力。方法:将体外诱导培养的成年犬骨髓基质干细胞,以1×106/cm2的密度接种到冻干骨基质(fdDBM)、磷酸三钙(TCP)、孔径分别为200μm及500μm的珊瑚羟磷灰石(CH200、CH500)等支架材料上,分别于体外培养的第4￣7天进行扫描电镜及石蜡切片HE染色,了解细胞在不同支架上的黏附及生长情况,并于1周后将大小为10mm×5mm×2mm的上述细胞支架复合物(fdDBM、TCP、CH200、CH500)分别植入裸鼠(n=8)背部皮下,每只裸鼠均植入4个实验组及1组无细胞的fdDBM空白支架对照组。9周后,取材行石蜡切片及HE染色,以IMAGER-PROPLUS软件测量每组的新生骨小梁量,并采用SAS软件包行单因素方差分析。结果:犬BMSCs与4种支架材料均黏附良好,TCP、CH200及CH5003组各样本均能观察到新骨形成,fdDBM及fdDBM空白对照组分别有75%、25%的样本有新骨形成;其中,TCP组的TBV值(28.2%±2.86%)显著高于CH200组(24.1%±4.12%)及CH500组(18.1%±4.66%)(P<0.01)。结论:BMSCs与4种材料的相容性良好。TCP与BMSCs复合后异位成骨效果显著,是很有希望的骨组织工程支架材料。     

Hydroxyapatite granule/carrier composites promote new bone formation in cortical defects

Background: A great deal of interest has been focused on finding substitutes for autogenous bone grafts. Among the most interesting materials are different calcium phosphate compositions (e.g., hydroxyapatite [HA]), due to their biocompatible properties in hard and soft tissue. Purpose: The bone response to porous ceramic HA granules in combination with two lipid and one polysaccharide carrier was evaluated in an experimental bone defect model in rabbits. Materials and Methods: Circular defects (Ø 4 mm) were made in both tibias of 32 rabbits. The 64 defects were divided into four groups. Group A was augmented with a composite of HA granules and a phospholipid‐diacetyl‐glycerol carrier, group B with HA granules and a phospholipid carrier, group C received HA granules and a sodium hyaluronan carrier, and group D served as control. The animals were killed after 6 weeks annd ground sections were evaluated using light microscopic morphometry. X‐ray microfluorescence (XRF) was applied in order to evaluate the suitability of this method to examine bone‐biomaterial interfaces. Calcium distribution was studied using x‐ray fluorescence line scans at selected interface regions of two sections in group B. Results: The HA/phospholipid composites were easier to shape and handle than the HA/hyaluronan composite. Group A had 36% newly formed bone area within the defect. Groups B and C showed significantly more newly formed bone within the defect (47% and 49%, respectively) compared to the control group (31%). The XRF analysis revealed that the amount of calcium in the newly formed bone was similar to that observed for the HA granules and slightly lower when compared to the mature, lamellar bone. Conclusions: Synchrotron radiation may be a new, suitable technique to study the interface between bone and bio‐materials with regard to mineral content. The results suggest that HA granule/lipid and HA granule/hyaluronan composites have interesting properties as bone‐substitute materials.     

自固化磷酸钙骨水泥修复牙种植体周围骨缺损实验研究

目的:本研究旨在应用国产自固化磷酸钙骨水泥修复牙种植体骨缺损的动物实验研究,观察磷酸钙骨水泥引导骨再生的方式,为将来磷酸钙骨水泥能修复牙种植体周围骨缺损奠定实验基础。方法:选取40只日本大耳白兔,在白兔右侧股骨大转子区植入BLB种植体(Φ=3.3 mm,L=8.0 mm),同时种植体冠部制造宽度为2.0 mm、深度为4.0 mm的环行骨缺损,骨缺损区充填CPC进行修复。实验组术后1、2、4、6个月随机处死大白兔10只,对骨缺损区X线骨密度分析,带种植体的硬组织磨片的组织学观察新骨的生成量,并进行统计学分析。结果:实验组磷酸钙骨水泥随时间延长而逐渐发生降解,新生骨组织沿降解裂隙长入,与种植体发生直接的接触,统计学分析结果表明各个月内的新骨量有显著性差别。结论:表明磷酸钙骨水泥在修复牙种植体周围骨缺损中展示了较好的引导骨再生性质。     

Neuartiges Knochenaufbaumaterial auf Kalziumphosphatbasis

Background

Up to now hydroxyapatite (HA) and β-tricalciumphosphate (β-TCP) ceramics have been routinely sintered at temperatures between 1100° and 1500°C. Our new calcium ceramic is fabricated by a sol-gel process at 200°C. The aim of this investigation was to test the biodegradation of and the induction of bone formation by this material.

Material and methods

Eighteen 1-year-old Goettingen minipigs were divided into three groups. Critical size defects (>5 cm³) in the mandible were treated differently in all three animals (group 1: filling with 40% β-TCP plus 60% HA, group 2: pure HA was applied, group 3 served as controls: only gelatinous material was given). Macroscopic and microscopic investigations of the former defects were made 8 months postoperatively.

Results

In groups 1 and 2 biodegradation of more than 93% of the new calcium phosphate formula was found 8 months postoperatively and considered to be very good. No difference was observed between pure HA (group 2) and the combination of HA and β-TCP (group 1). In both groups complete bone formation was seen macroscopically in the former defects. In the control group only incomplete bone formation with 48.4% of the defect area was noted. This difference was significant (p<0.001).

Discussion

The new calcium phosphate formula made by a sol-gel method at 120°C seems to be suitable for filling bone defects and is of interest for orthopedic surgery, traumatology, craniomaxillofacial surgery, and dentistry.     

提取并部分纯化bBMP促进节段性骨缺损愈合的定量组织学研究

目的　从小牛骨基质中提取并部分纯化bBMP ,以促进节段性骨缺损的愈合。方法　通过SDS PAGE电泳及生物活性鉴定实验 ,证实bBMP保留了其活性蛋白成分 ,具有良好的骨诱导活性。在此基础上 ,合成一种新型复合人工骨材料即HA bBMP Co ,用以整复家兔尺骨中段 1.5cm节段性骨缺损 ,并对缺损区新骨生长量进行定量组织学测定。结果　HA bBMP Co复合人工骨植入整复节段性骨缺损 ,其新骨生长量明显高于同期HA Co复合人工骨组 (P <0 .0 1)。结论　HA bBMP Co复合人工骨能有效地促进节段性骨缺损的愈合 ,是一种具有良好应用前景的骨替代材料     

Biomechanical and histological studies of particulate hydroxylapatite implanted in femur bone defects of adult dogs

The purpose of this study was to investigate the biomechanical behavior and the histology of particulate hydroxylapatite (HA) implanted in bone defects created in femurs of 48 adult mongrel dogs. The bone defects, measuring 10 x 10 x 25 mm with or without HA implantation, were allowed to heal until the end of the 1st, 2nd, 3rd, 6th, 9th and 12th months after surgery. The harvested tissue specimens from the implant sites were processed into long cubic or rectangular prismatic forms. Their mechanical strengths were assessed using compression and shearing tests to measure the maximal compressive and shear stress by force loading on the middle portions of the specimens. Histological sections of each stage were processed with both decalcified and nondecalcified methods. The results showed that the mechanical strength of the tested specimens was closely related to the tissue regeneration within the bone defect. Progressive regeneration of new bone was observed at each stage, with complete bone formation at the 9-month period. A consistent increase in both maximal compressive stress and maximal shear stress was noted at each stage, responsive to the ossification and maturation of the regenerating tissue within the bone defect. This animal model provides a novel approach to directly estimate the tissue strength of the HA-implanted bone defect.     

Guided bone regeneration around titanium plasma-sprayed,acid-etched,and hydroxyapatite-coated implants in the canine model

BACKGROUND: Endosseous dental implants with rough surfaces have been designed to improve early healing, especially in areas of poor bone or insufficient bone quantity. The aim of this study was to histomorphometrically assess the bone-to-implant contact on 3 different rough-surfaced implants following guided bone regeneration. METHODS: Mandibular premolars and first molars were extracted in 12 dogs, and healing was allowed for 6 months. Six implant osteotomy sites were prepared, 3 per side, followed by the creation of 7.3 mm wide by 5 mm deep surgical defects in the coronal section of the osteotomy sites. Ten-mm long titanium screw-type implants with titanium plasma-sprayed (TPS), hydroxyapatite-coated (HA), or acid-etched (AE) surfaces were placed; the surrounding defects were filled with canine demineralized freeze-dried bone allograft; implants/grafts were covered with expanded polytetrafluoroethylene membranes; and the tissue was closed. Following a healing period of 4 months, the animals were sacrificed and mandibular blocks were harvested for histomorphometric analysis. RESULTS: The mean percentage of bone-to-implant contact in the defect and non-defect areas for the different implant surfaces was: AE 16.24% defect, and 28.78% non-defect; TPS 25.08% defect, and 16.96% non-defect; and HA 48.25% defect and 26.60% non-defect. Within the defect, the mean difference in the bone-to-implant contact was significant for HA compared to TPS (P < 0.0001) and HA versus AE (P < 0.0001); TPS versus AE was not significant (P = 0.063). In the non-defect areas, the mean difference in the bone-to-implant contact was significant for AE versus TPS (P = 0.010); all other comparisons were not significant. There were 18 membrane exposures in the 72 implant sites. Data were analyzed again to assess the impact of membrane complications. Using a 1-way analysis of variance, the bone-to-implant contact was compared between the sites with and without membrane complications. No significant differences were seen in the defect areas or in the non-defect areas between the sites with and without membrane complications. CONCLUSION: In this study, the bone-to-implant contact in regenerated bone was greatest when an HA-coated implant was used.