冷冻异体骨膜引导骨组织再生的实验研究

目的：探讨用冷冻异体骨膜作为引导骨组织再生膜的可能性;方法：取兔颅骨顶部骨膜经冷冻处理,在３１只日本大耳白兔的下颌骨造成两处骨缺失,采取同体对照,一处表面覆盖冷冻异体骨膜,另一处不覆盖。分别在第４、８、１２、１６周处死动物,行Ｘ线及组织学观察。结果：冷冻异体骨膜不产生排斥反应,可在体内维持８￣１２周,具有良好的阻挡纤维组织长入骨创面、分隔不同细胞及引导组织再生的功效。结论：冷冻异体骨膜是一种理想的     

血小板富集凝胶与骨组织再生

血小板富集凝胶合有多种浓缩的生长因子。早期以一种生物凝胶和屏障膜的作用应用于临床。近来发现其能促进软组织的愈合和骨组织的再生。本文对血小板富集凝胶的发展概况、临床应用及其研究进展作一综述。     

膜引导骨组织再生术在上颌前牙区种植中的应用

目的:探讨膜引导骨组织再生(membrane guided bone regeneration,MGBR)技术中,生物胶原膜在上颌前牙区种植骨增量中的作用.方法:选取我院2008年1月至2009年12月间上前牙区唇腭向骨量不足种植病例55例,随机分为2组,29例使用MGBR,同期植入种植体40颗(有膜组);另26例不应用MGBR,植入种植体40颗(无膜组),作为对照.观察2组患者种植前及修复前种植区牙槽骨的情况.用卡尺测量牙槽骨唇腭向厚度,用X线骨密度分析法评估平均密度的变化.采用X线片图像分析测量软件(Sidexis)和SPSS16.0软件包进行比较分析.结果:单因素分析显示,有膜组种植术前与永久修复前牙槽骨唇腭向的厚度及密度差别有统计学意义(P<0.05);种植术前与永久修复前,有膜组与无膜组牙槽骨唇腭向厚度及骨密度变化的差别有统计学意义(P<0.05).结论:使用生物膜的患者,唇腭向骨厚度及密度的增加均优于未使用生物膜的患者.在上前牙区骨量不足患者的种植术中,可推荐使用MGBR技术.     

骨膜细胞促进骨缺损修复的研究进展

创伤、肿瘤等疾病导致的骨缺损在临床上十分常见,如何有效促进骨缺损修复仍是一大挑战.目前,越来越多的临床证据显示骨膜在促进骨缺损修复中起到了重要作用;一系列研究表明,缺损发生后,骨膜中的细胞可以动员迁移到骨缺损处,直接参与缺损修复.本文将对骨膜的发育来源、骨膜细胞在缺损修复中的生物学作用以及骨膜细胞群体的异质性加以综述,...     

骨髓单个核细胞在骨组织工程研究中的应用

骨髓单个核细胞是骨髓经过简单的密度梯度离心而得到的含多种原始多潜能细胞的混合细胞群,在适当条件下能分化成骨、软骨、脂肪等,可分泌各种促进组织再生修复的生长因子。不经过体外培养过程而直接植入或与支架材料复合植入骨缺损,可增强缺损区的血管新生和骨再生,在骨组织工程领域有广阔的临床应用前景。     

可吸收膜在引导骨再生中的应用研究

引导骨再生（Guided Bone Regeneration,GBR）是指利用屏障膜引导骨组织再生防止周围纤维结缔组织过早长入骨缺损区,改变骨创愈合环境,从而促进骨组织再生修复。本文对临床常见的可吸收膜做一综述,研究其在引导骨再生中的作用。     

引导骨组织再生膜的研究进展

引导骨组织再生术(guided bone regeneration, GBR)是目前促进骨组织再生的有效手段,而GBR膜是决定其临床效果的主要因素之一,也是该领域的重点关注内容。GBR膜在骨组织再生中不仅具着物理性屏障膜的作用,同时还能起到保护局部血块、聚集骨诱导因子、进行骨传导等作用。本文将对膜引导骨组织再生的机理、GBR膜的制备技术及分类、GBR膜的发展趋势等方面进行论述。     

骨引导再生技术在牙槽骨骨量不足牙种植术中的应用

目的:评价骨引导再生技术在牙槽骨骨量不足患者牙种植术的应用效果.方法:对23例31颗牙槽骨骨量不足患者,种植体周围骨缺损处用人工骨粉植入及胶原生物膜覆盖.随访6-12个月,通过临床检查及x线曲面断层片,观察其临床效果.结果:随访6-12个月,种植牙形态及功能良好,x线检查未见明显骨吸收.种植牙100％成功.结论:对牙槽骨骨量不足患者,同期行GBR和种植体植入术后,可以重建缺损的骨组织,临床效果满意.     

膜引导骨组织再生技术应用于即刻种植的实验研究

目的:探讨膜引导骨组织再生技术(membrane guided bone regeneration,mGBR)在即刻种植中的应用。方法:16颗钛75种植体种植于犬下颌第3、4前磨牙新鲜拔牙创,左侧(实验侧)置胶原膜,右侧无膜对照,术后4周、12周通过形态学和定量组织学分析研究种植体骨界面。结果:全部实验动物伤口愈合良好,术后4周和12周实验侧新骨形成均多于对照侧;实验测种植体直接骨接合率(DCLF,%)分别为32.93±2.66和65.95±7.00,对照侧为21.71±3.20和45.72±3.51。组间比较P<0.01。结论:mGBR可提高即刻种植成功率。     

Contribution of the periosteum to bone formation in guided bone regeneration. A study in monkeys

The periosteum has been referred to as a protective barrier in the regeneration of bone defects. The objective of this study was to determine the contribution of periosteum as a natural barrier to bone formation in guided bone regeneration. Mucoperiosteal flaps were elevated bilaterally on the buccal aspect of the mandibular angle in 5 cynomolgus monkeys. Bleeding was induced by perforating the cortical bone. A hemispherical titanium mesh was fixed over the areas thus creating a void 5 mm in height between the mesh and the bone surface. One one side the mesh was covered with an ePTFE membrane (test side). The contralateral side did not receive further treatment (control side). After 4 month healing, histomorphometric analyses were used to determine the percentage of new bone in the void underneath the mesh, and the ratio between mineralized tissue and marrow spaces in new and old bone. The mean percentage of new bone tissue was 77.2 +/- 7.5% for the test sides and 68.6 +/- 8.4% for the control sides (P = 0.018, t-test). This new bone contained 80.0 +/- 3.6% mineralized tissue in the test group and 82.5 +/- 5.0% in the control group (P > 0.05, t-test). In both groups the newly formed bone exhibited significantly less mineralized tissue than the old bone (P < 0.05, t-test). It is concluded from this study that new bone formation was enhanced by the additional use of an ePTFE membrane under a periosteum-lined mucoperiosteal flap when space maintenance was excluded as a critical factor.     

Role of periosteum in the formation of jaw bone

Abstract The aim of the present investigation was to evaluate the bone-forming capacity of the outer (fibrous) and inner (cambium) layer of the mandibular periosteum in skeletally mature rats. The experiment was carried out in 25 rats. The mandibular ramus was exposed on one side (experimental side) after elevation of a muscle-periosteal flap. A teflon capsule was placed with its opening facing the periosteum at the subsurface of the raised muscle-periosteal flap after suturing. In the contralateral side serving as control, the periosteum of the lateral aspect of the mandibular ramus was left intact. This time the teflon capsule was placed with its opening facing the periosteum left behind at the ramus. The histological analysis demonstrated that in all experimental and control specimens, some bone was produced at 7 days after operation. In the experimental specimens, however, both the incidence and the amount of newly-formed bone in the teflon capsules gradually decreased from 7 to 120 days, while increasing in the control capsules placed over the periosteum. At 120 days, the mean amount of new bone produced in the experimental capsules was 3% (range 0–15%) of the total space created by the capsule, while it was 68% (range 41–85%) for the control capsules. The results demonstrated that substantial amounts of bone can be produced predictably by the placement of an occlusive teflon capsule facing mandibular covered with periosteum. Bone produced from the periosteum and without continuity with existing bone becomes resorbed with time.     

冷冻异体骨膜引导即刻种植体周围骨缺损修复的临床研究

目的：观察机体对冷冻异体骨膜的反应及其引导骨组织再生的效果，方法：在实验研究成功的基础上，将冷冻异体骨膜作为引导组织再生膜性材料应用于引导即刻种植义齿植体周围骨缺损的修复。结果：临床观察证实机体对冷冻异体骨膜无排斥反应，膜无脱出，无感染，骨缺损修复率达到92．12％，结论：冷冻异体骨膜是一种理想的引导组织再生膜性材料。     

Enhancement of bone volume in guided bone augmentation by cell transplants derived from periosteum: an experimental study in rabbit calvarium bone

Bone morphology is genetically encoded and it is usually difficult to change its structure without invasive surgery. We have tried to stimulate bone augmentation by a combination of guided bone regeneration techniques and cell transplants with collagen scaffolds for the suitable skeletal framework. In vitro-expanded tibia periosteum cells were used to promote osteogenesis with collagen scaffolds and titanium (Ti) or poly-L-lactic acid (PLLA) caps as barriers to create a space facing connective tissue under calvarium skin. This approach was assessed in the defective skull bone of a rabbit model. After a 12-week healing period, histomorphometric analyses were performed to determine the percentage of newly formed mineralized tissue in the cap. The mean percentage of newly formed mineralized tissue within the cap was 15.4%+/-3.99 for the Ti cap group, 15.5%+/-4 for the PLLA cap group, 6.19%+/-4.94 for the PLLA cap+collagen carrier group and 23.1%+/-23.1 for the PLLA+collagen carrier+cell transplants group. The cell transplant group showed a significantly higher value than other groups (P<0.05, Wilcoxon signed rank test, Mann-Whitney U-test). This approach of guided bone augmentation and cultured cell transplants with collagen carrier exhibited significantly greater morphogenesis of mineralized tissue than the control over a 12-week experimental period.     

Bone regeneration of dental implant dehiscence defects using a cultured periosteum membrane

OBJECTIVES: This study aimed to demonstrate the feasibility of a cultured periosteum (CP) membrane for use in guided bone regeneration at sites of implant dehiscence. MATERIAL AND METHODS: Four healthy beagle dogs were used in this study. Implant dehiscence defects (4 x 4 x 3 mm) were surgically created at mandibular premolar sites where premolars had been extracted 3 months back. Dental implants (3.75 mm in diameter and 7 mm in length) with machined surfaces were placed into the defect sites (14 implants in total). Each dehiscence defective implant was randomly assigned to one of the following two groups: (1) PRP gel without cells (control) or (2) a periosteum membrane cultured on PRP gel (experimental). Dogs were killed 12 weeks after operation and nondecalcified histological sections were made for histomorphometric analyses including percent linear bone fill (LF) and bone-to-implant contact (BIC). RESULTS: Bone regeneration in the treatment group with a CP membrane was significantly greater than that in the control group and was confirmed by LF analysis. LF values in the experimental and the control groups were 72.36+/-3.14% and 37.03+/-4.63%, respectively (P<0.05). The BIC values in both groups were not significantly different from each other. The BIC values in the experimental and the control groups were 40.76+/-10.30% and 30.58+/-9.69%, respectively (P=0.25) and were similar to native bone. CONCLUSION: This study demonstrated the feasibility of a CP membrane to regenerate bone at implant dehiscence defect.     

Guided bone regeneration in dental implant treatment using a bioabsorbable membrane

The aim of this study was to evaluate an osteopromotive technique, using a bioabsorbable membrane, for its ability to restitute bone over buccal fenes-tration and dehiscence defects following fixture installation. 11 patients requiring dental implant treatment and exhibiting sufficient vertical height of the maxilla and compromised bucco-palatal dimensions, as determined clinically and radiographically, were included in the study. 17 Brånemark® titanium fixtures were placed with buccal defects which were augmented by a bioabsorbable membrane, Resolut®. No complications were observed post-operatively. At 6-8 months, abutment connection was performed, and clinical evaluation of the healed defect area was made. The number of exposed buccal threads at fixture installation (median 8; range 2-19), and abutment connection (median 0; range 0-5), respectively, was compared. Out of the 17 fixtures; 14 exhibited complete coverage with bone, whereas 3 showed some remaining threads. A small punch biopsy taken at abutment connection in an area where the membrane had been placed showed a combination of dense connective tissue and bone. Radiographic evaluation of the marginal periimplant bone level is in progress and results to date show a median bone loss of 1.2 mm after a loading period of 4-6 months. Results show that fixture dehiscence and fenestrations, augmented with this bioabsorbable membrane, demonstrate a highly significant amount of new bone formation.     

A comparative study of barrier membranes as graft protectors in the treatment of localized bone defects. An experimental study in a canine model

Guided bone regeneration is a predictable and well-documented surgical approach for the treatment of deficient alveolar ridges prior to endosseous implant placement. The purpose of this study was to compare a new resorbable membrane (GORE RESOLUT ADAPT Regenerative Membrane, i.e. 67% glycolide (PGA) : 33% trimethyline carbonate (TMC)) with Bio-Gide, a resorbable collagen membrane. Five canines were used in the study. Three saddle-type osseous defects were created bilaterally in edentulous areas of the mandible. The defects were filled with assayed, canine demineralized freeze-dried bone (DFDB) in a thermoplastic gelatin matrix. Using a randomized block design, four sites were covered with PGA : TMC membranes of four different porosities, one site was covered with a collagen membrane and one site consisted of DFDB alone (control). At 3 months, the animals were euthanized and the mandibles were removed en bloc for laboratory processing. A total of 30 sites were reviewed microradiographically and underwent histomorphometric analysis for bone regeneration, soft tissue presence and remaining graft material. All sites exhibited uneventful healing. A significantly higher percentage of bone regeneration was seen in the sites protected by the PGA : TMC membrane. A higher component of soft tissue was visible beneath the collagen membrane as compared with the PGA : TMC membrane. The control sites exhibited noticeable deformation of the regenerated bone secondary to collapse of the overlying periosteum. The authors conclude that the PGA : TMC membrane protected the DFDB-filled defect and allowed a greater amount of bone regeneration than the defect protected by the collagen membrane or the control.