犬股骨髁松质骨挤压后愈合过程的骨形态计量学研究

目的通过建立松质骨挤压的动物模型,模拟临床种植体挤压植入术,测量骨形态计量学参数,观察松质骨挤压后愈合过程中骨小梁排列的变化,为骨挤压技术的使用和改进提供实验依据和支持。方法以犬股骨髁松质骨为挤压部位,选择敲击挤压法,使用自行研制的挤压器,按照不同的挤压程度进行逐级挤压、备洞,植入与种植窝直径相同的圆柱状纯钛种植体。按照不同观察时期（1、2、4、12周）处死动物,取材,制作Messon染色硬组织切片,采用Osteomeasure软件测量骨形态计量学参数。结果松质骨受挤压后,在一定时期内骨小梁数增多,骨小梁间距减小,骨小梁厚度基本不变。前两者改变在2周内的愈合期比较明显,从第4周开始,经过12周的愈合,各参数与对照组之间趋于一致。结论骨挤压技术在一定时期内能够提高种植窝周骨小梁的致密度,可能有益于提高种植体的初期稳定性。     

颅面骨生长发育及正畸治疗中的3种骨调控机制及其概念

骨生长（bone growth）、骨塑建（bone modeling）和骨重建（bone remodeling）是出生后骨组织生长发育的3种调控机制。长期以来,在口腔正畸学领域中,由于一些历史原因,骨塑建与骨重建（或称骨改建）的概念被混淆,真正的骨重建机制却被忽略。本文从历史的角度回顾了这个语义学错误在口腔正畸学领域产生的原因,进一步阐明了骨塑建与骨重建机制的区别,以及出生后颅面骨骼生长发育与正畸治疗中的骨调控机制。建议尽快在口腔正畸学领域宣传、推广正确使用骨塑建和骨重建这2个专业名词的中英文拼写,停止使用骨改建这一中文名词,以避免在与其他学科（如骨科学）或国内外同行交流时发生误解和交流障碍。     

冷冻/冷冻干燥处理对犬下颌骨生物力学性能的影响

目的:探讨深低温冷冻/冷冻干燥处理对下颌骨生物力学性能的影响。方法:将12具新鲜比格犬下颌骨随机分成2组,第1组分为新鲜组和冷冻组、第2组分为新鲜组和冷冻干燥组,分别进行抗压和抗弯曲实验。结果:抗弯曲实验中冷冻骨和冻干骨的最大载荷与新鲜骨没有显著差别,抗弯曲实验中冷冻骨和冻干骨的最大载荷显著低于新鲜骨,分别降低了24%和30%,刚度显著高于新鲜骨。结论:经过冷冻或者冷冻干燥处理的同种异体下颌骨保持着较好的抗压能力,尽管抗弯曲能力下降较多,仍可以在移植后提供足够的支持力。     

高压蒸气骨移植的组织形态学研究

作者用SD系大白鼠28只,分为实验组(16只)和对照组(12只),实验组将大白鼠头顶骨部分切除,用高压蒸气处理后再植回原位;对照组将切除的骨不作任何其他处理再植回原位.术后用光学显微镜和扫描电镜进行组织形态学观察,结果显示;实验组自术后1周开始有新骨形成,和对照组相同.4周时新骨形成最旺盛,移植骨大部被新生骨取代.8周时宿主骨和移植骨完全是骨性连接.结果表明:高压蒸气骨是一种具有良好生物相容性和骨传导能,并有一定机械强度的骨移植材料.     

两种自体骨粉末修复种植体周围骨缺损的临床研究

目的：评价自体骨夹层法修复种植体周围骨缺损的近期临床效果。方法：48例患者共82颗种植体,植入的种植体唇侧骨壁缺损,其余三个骨壁都存在,随机分为两组：一组为混合法,22例患者39颗种植体,自体骨粉与Bio-Oss骨粉按1：1比例混合修复骨缺损部位。另一组为夹层法,26例患者43颗种植体,局部微量刮取自体骨粉涂于暴露的种植体表面,再覆盖Bio-Oss骨粉,再覆盖生物膜。植入6个月后行上部修复。修复后追踪时间平均24个月。根据临床、X线检查和患者主诉评价修复效果。结果：两组均无种植体脱落,存留率100%,二者差异无统计学意义。其龈袋深度、出血指数、年累计骨吸收量及X线检查均无明显不同。结论：对于骨缺损的病例,采用自体骨夹层法可以应用于临床。近期效果良好,长期效果有待追踪。     

牙种植手术中自体骨的收集和应用

目的：研究牙种植过程中，收集自体骨即刻移植修复种植体周围小型骨缺损的临床疗效。方法：2003年10月至2005年10月，选择14例牙种植患者，植入25颗种植体时发生17处骨缺损，其中开窗式骨缺损9处，烦（舌）侧种植体颈部暴露8处。在牙种植窝制备过程中，应用自制的集骨器收集随冷却水流出的骨屑，并将其即刻移植或与Bio—oss混合后移植修复骨缺损。结果：牙种植术后3-6个月，原缺损处局部形态饱满，X线片示种植体与周围牙槽骨形成良好的骨结合，二期手术时见缺损处巳覆盖成熟骨质，移植骨成活良好。结论：应用自制集骨器获得的收集骨修复种植体周围小型骨缺损，方法简单实用。     

A novel bone scraper for intraoral harvesting: a device for filling small bone defects

AIM: To evaluate histologically the morphology and characteristics of bone chips harvested intraorally by Safescraper, a specially designed cortical bone collector. MATERIAL AND METHODS: Bone chips harvested near a bone defect or in other intraoral sites were grafted into a post-extractive socket or applied in procedures for maxillary sinus floor augmentation or guided bone regeneration. Core biopsies were performed at implant insertion. Undecalcified specimens embedded in PMMA were studied by histology, histochemistry and SEM. RESULTS: Intraoral harvesting by Safescraper provided a simple, clinically effective regenerative procedure with low morbidity for collecting cortical bone chips (0.9-1.7 mm in length, roughly 100 microm thick). Chips had an oblong or quadrangular shape and contained live osteocytes (mean viability: 45-72%). Bone chip grafting produced newly formed bone tissue suitable for implant insertion. Trabecular bone volume measured on biopsies decreased with time (from 45-55% to 23%). Grafted chips made up 50% or less of the calcified tissue in biopsies. Biopsies presented remodeling activities, new bone formation by apposition and live osteocytes (35% or higher). DISCUSSION AND CONCLUSIONS: In conclusion, Safescraper is capable of collecting adequate amounts of cortical bone chips from different intraoral sites. The procedure is effective for treating alveolar defects for endosseous implant insertion and provides good healing of small bone defects after grafting with bone chips. The study indicates that Safescraper is a very useful device for in-office bone harvesting procedures in routine peri-implant bone regeneration.     

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.     

胶原膜与骨形成蛋白复合物的成骨作用研究

目的：评价rhBMP-2／胶原复合膜对大鼠颅内缺损修复的作用。方法：将rhBMP-2与胶原膜复合,在大鼠颅骨制备直径5mm的骨缺损,分别予双侧覆盖复合膜、外侧覆盖复合膜,外侧覆盖胶原膜作为空白对照,于术后2、4、6周,取标本进行X线检查、荧光显微镜检查及常规组织学观察。结果：在各组内、覆盖复合膜的缺损成骨面各百分比及新生骨面积均明显高于覆盖胶原的缺损组（P＜0．01）,术后6周,双侧覆盖复合膜的缺损已达骨性愈合。结：胶原膜与BMP的复合物不但具有机械性的阻挡作用,而且具有骨诱导性,可加速骨愈合。     

The Influence of PRP on Early Bone Formation in Membrane Protected Defects. A Histological and Histomorphometric Study in the Rabbit Calvaria

Background: Platelet rich plasma (PRP) has been proposed to be a useful adjunct to bone grafting. Purpose: The aim of the present study was to assess new bone formation in bone regeneration procedures using platelet rich plasma (PRP) alone or in combination with autogenous bone. Materials and Methods: Four surgically created, monocortical defects 5 mm in diameter in the calvariae of 15 New Zealand rabbits were grafted with a coagulum‐filled control, PRP, particulated autogenous bone alone (A), or combined with PRP (A‐PRP). Results: Mean platelet concentration of 1,761,930 ± 680,200/µl was achieved (5.30 ± 2.63 × fold of baseline). Animals were sacrificed 1, 2, and 4 weeks later. Histomorphometric analysis showed no statistical difference for total new bone formation at any time point, however, a detailed analysis revealed a statistically significant higher percentage of lamellar bone than woven bone for the autogenous bone group at 2 weeks; all other groups demonstrated equal percentages of either bone type. At 4 weeks, all groups revealed a statistically greater component of lamellar bone over woven bone. Graft resorption rate was similar for both A and A‐PRP. PRP platelet concentration was significantly positively correlated with TGF‐beta1 but not with PDGF‐AB. Conclusions: Within the limits of the chosen animal model, this study demonstrated that PRP during early healing, whether alone or mixed with autogenous bone, did not lead to greater bone remodelling, as compared to coagulum. In contrast, autogenous bone alone demonstrated accelerated bone remodelling at 2 weeks.     

实验犬磨牙根分叉骨缺损应用组织工程骨修复的效果分析

目的观察以组织工程方法修复大面积根分叉骨缺损的效果。方法以成骨条件培养液培养实验犬骨髓基质细胞(BMSCs)至第3代并以1×106/cm2的密度与猪的脱矿冻干骨(fdDBM)复合培养后回植于犬磨牙根分叉骨缺损区(2.0cm×1.0cm×0.8cm)。术后3个月与6个月取实验开窗区骨制作组织切片或2mm厚的骨磨片,观察新生骨组织形态及骨钙素与Ⅰ型胶原表达情况并作骨磨片的骨密度分析。所得数据用SAS6.12软件作t检验。结果6个月及3个月实验侧骨缺损完全修复。骨切片显示实验侧开窗区新生骨与正常骨无明显区别且Ⅰ型胶原和骨钙素表达亦同正常。X线骨密度数据显示回植后6个月实验组的骨密度高于对照组及回植3个月者。结论以组织工程骨修复大面积根分叉骨缺损是可行的。