应用细胞-支架构建方式的组织工程方法促进牙周组织再生的实验研究

目的:观察评价细胞 -支架构建方式的组织工程方法对牙周组织再生修复的影响和意义,探讨自体牙周膜细胞(PDLCs)和纳米羟基磷灰石材料 -纳米羟晶 -胶原仿生骨材料 (nHAC)分别用作牙周组织工程种子细胞和支架材料的可行性。方法:改良组织块法体外培养动物自体PDLCs,传代扩增后接种到nHAC三维支架上,再植入动物人工牙周组织缺损,表面覆盖聚四氟乙烯 (e-PTFE)膜,以单纯翻瓣组和单纯GTR组作为对照。术后 8周进行组织学观察和测量,分析评价其牙周组织的再生情况。结果:自体PDLCs-nHAC-膜复合植入组较单纯翻瓣组和单纯GTR组有更多的新生牙槽骨、新生牙周膜和新生牙骨质生成,且未见上皮长入。结论:应用细胞-支架构建方式的牙周组织工程方法能更有效地促进牙周组织再生和重建,而自体PDLCs可作为牙周组织工程的种子细胞,nHAC可作为牙周组织工程的支架材料。     

细胞-支架构建方式的牙周组织工程实验研究

目的　观察评价细胞 支架构建方式的组织工程方法对牙周组织再生修复的影响和意义。方法　体外培养动物自体牙周膜细胞 (PDLCs) ,传代扩增后接种到纳米羟基磷灰石材料 (nHAC)三维支架上 ,扫描电镜观察PDLCs在nHAC支架上的附着及生长情况 ;同时 ,将PDLCs nHAC复合物植入动物牙周组织缺损中 ,术后 8周观察 ,评价其牙周组织的再生情况。结果　扫描电镜显示 ,nHAC具有良好的多孔网状结构 ,PDLCs在nHAC上贴附牢固 ,生长旺盛。动物实验可见 ,PDLCs nHAC植入组较对照组有更多的新生牙槽骨、新生牙周膜和新生牙骨质生成 ,缺损处牙周组织几乎完全再生 ,且未见上皮长入。结论　应用细胞 支架构建方式的牙周组织工程方法能获得理想的牙周组织再生和重建。     

骨形成蛋白促进牙周组织再生的动物实验研究

目的将骨形成蛋白（ｂｏｎｅｍｏｒｐｈｏｇｅｎｅｔｉｃｐｒｏｔｅｉｎ，ＢＭＰ）联合应用于牙周引导组织再生（ｇｕｉｄｅｄｔｉｓｓｕｅｒｅｇｅｎｅｒａｔｉｏｎ，ＧＴＲ）技术中，观察和比较其对牙周组织再生修复的影响和意义。方法制备狗下颌后牙区人工骨缺损，于清创后分组置入引导膜材料和ＢＭＰ，以常规翻瓣术为对照；分不同时期取材做组织学观察和评价。结果实验组较对照组新生组织量多，而以复合ＢＭＰ组效果最为显著；膜材料在早期有一定抑制结合上皮根向迁移的作用。结论利用外源性ＢＭＰ的主动生物诱导活性，可望应用于临床促进牙周硬组织成分的新生修复。     

胶原-羟基磷灰石人工骨与胶原膜引导牙周组织再生的动物实验研究

目的：将胶原-羟基磷灰石人工骨与胶原膜联合应用于修复牙周缺损的动物实验,探讨其用于引导牙周组织再生的可行性。方法：人工构建4只成年Beagle犬下颌后牙区牙周缺损模型,分别随机采用：胶原-羟基磷灰石人工骨/胶原膜、胶原-羟基磷灰石人工骨、空白对照治疗,每组8颗牙,12周后处死动物,进行组织学观察并测量新生组织高度。结果：与单纯植入胶原-羟基磷灰石人工骨组相比,胶原-羟基磷灰石人工骨/胶原膜组获得了更多的新附着,表现为有较多的新生牙槽骨、新生牙周膜和新生牙骨质样组织生长,2组之间新生组织差异有显著性（P〈0.05）。结论：胶原-羟基磷灰石人工骨与胶原膜联合运用修复牙周牙槽骨缺损引导牙周组织再生的效果优于单纯植入人工骨。     

贝壳多孔羟基磷灰石基骨修复材料和骨形成蛋白-2联合应用引导犬牙周组织再生效果初步评估

目的初步评估贝壳多孔羟基磷灰石基骨修复材料及该材料和骨形成蛋白-2联合应用引导比格犬牙周组织再生的效果。方法选取18月龄比格犬6只,牙周基础治疗后1周,在下颌第二、三、四前磨牙,建立急性牙周骨缺损模型,依照分组情况进行不同治疗。实验组（T组）植入骨修复材料和骨形成蛋白-2;阴性对照组（NC组）植入骨修复材料;空白对照组（BC组）不植入任何材料。实验设计采取同颌同名牙对照,同一只比格犬的3对同颌同名牙分别为：空白对照组和阴性对照组,阴性对照组和实验组,空白对照组和实验组。术后12周,处死动物,Micro-CT检查并对数据进行统计学分析。结果材料植入后,未见材料溢出,植入局部和全身都未见明显不良反应。3组缺损都有一定程度骨再生,以T组再生组织量最多,BC组最少。Micro-CT结果显示：T组、NC组和BC组的骨再生平均高度为（4.50±0.47）mm（、1.75±0.42）mm和（0.87±0.31）mm。NC组和BC组相比,差异有统计学意义（P〈0.05）。T组与NC组和BC组相比,差异均有统计学意义（P〈0.05）,且有临床意义。结论贝壳多孔羟基磷灰石基骨修复材料和骨形成蛋白-2联合应用于比格犬,可以获得更好的引导组织再生效果。     

纳米羟基磷灰石材料复合碱性成纤维细胞因子促进牙周组织再生的实验研究

目的:探讨新型纳米羟基磷灰石材料—纳米羟晶/胶原仿生骨材料(nHAC)作为生长因子载体和牙周组织工程支架材料应用的可行性,观察评价其对牙周组织再生修复的影响和意义。方法:将人牙周膜细胞(HPDLCs)接种于nHAC三维支架上复合培养,体外扫描电镜观察HPDLCs在nHAC支架上的附着、生长情况,并将碱性成纤维细胞生长因子(bFGF)与nHAC复合植入动物人工牙周组织缺损,表面覆盖聚四氟乙烯(e-PTFE)膜,以空白对照组和单纯置膜组作为对照。术后8周进行组织学观察和测量,分析评价其牙周组织的再生情况。结果:扫描电镜可见nHAC具有良好的多孔网状结构,PDLCs在nHAC支架上贴附紧密,生长旺盛,伸展充分,动物实验结果显示nHAC/bFGF/膜复合植入组较空白对照组和单纯置膜组有更多新生的牙槽骨、牙周膜和牙骨质生成,结果具有显著性差异。结论:nHAC具有良好的三维空间结构和细胞相容性,与bFGF复合植入牙周缺损后可显著促进牙周组织再生,提示nHAC有望成为理想的生长因子载体和牙周组织工程支架材料。     

骨髓基质细胞-乌贼骨转化羟基磷灰石复合物促进牙周组织再生的研究

目的：评价乌贼骨转化羟基磷灰石材料(CBHA)复合骨髓基质细胞(BMSC)修复牙周缺损、促进牙周再生治疗的可行性。方法：体外培养犬BMSC，复合CBHA后移植到犬下颌后牙的根分叉骨缺损中，8周后进行组织学观察。结果：BMSC—CBHA组新生牙周组织量明显高于CBHA组、对照组。结论：BMSC—CBHA复合物可加快牙周组织的再生，有望成为牙周再生细胞的来源。     

骨形成蛋白-2与其他生长因子联合应用对骨再生的影响

随着组织工程的发展,越来越多的生长因子被应用到组织工程中参与骨组织的改建与修复再生,骨形成蛋白-2(bone morphogenetic protein 2,BMP-2)是最为常用的促进成骨分化及骨组织再生的生长因子,并且BMP-2与其他因子的联合应用成为目前研究的热点,该文主要阐述BMP-2与其他因子联合应用时所产生的促成骨效应及其作用机制。     

牙周膜细胞松质骨基质支架复合移植促进牙周组织再生的研究

目的观察牙周膜细胞（PDLCs）接种松质骨基质（CBM）支架复合移植对牙周组织再生修复的影响和意义。方法将体外培养的狗自体PDLCs接种到CBM三维支架上,体外进行细胞计数和扫描电镜观察,并植人狗人工牙周组织缺损处,表面覆盖聚四氟乙烯膜（e-PTFE）,以单纯翻瓣组和只覆盖e-PTFE组作为对照。术后8周对动物组织标本进行组织学观察和测量,分析比较各组牙周组织的再生情况。结果PDLCs在CBM支架材料上形成良好的贴附并增殖,扫描电镜可见CBM具有良好的多孔网状结构,细胞在CBM上生长旺盛,伸展充分。自体PDLCs／CBM／e-PTFE膜复合植入组较单纯翻瓣组和e—PTFE组有更多的新生牙槽骨、新生牙周膜和新生牙骨质生成,且未见上皮长入。结论PDLCs接种松质骨基质支架复合移植能更有效地促进牙周组织再生和重建,CBM有望用作牙周组织工程的支架材料。     

多孔β-0TCP/BMP复合人工骨引导牙周组织再生的实验研究

目的　将骨形成蛋白 (bonemorphogeneticprotein ,BMP)和多孔 β磷酸三钙 (β tricalciumphosphate ,β TCP)复合人工骨联合应用于引导组织再生 (guidedtissueregeneration ,GTR)技术中 ,评价其对Ⅱ度根分叉病变牙周组织再生修复的影响和意义。方法　用健康成年杂种狗 4只 ,制备下颌后牙区人工骨缺损。实验牙位随机分为 3组 :①骨形成蛋白 /引导组织再生 (BMP/GTR)组 :缺损处植入引导膜材料和复合人工骨 ;②GTR组 :单纯放置引导膜材料 ;③以常规翻瓣术为对照组。术后 12周取材做组织学观察和评价。结果　两实验组均有明显新附着形成 ,其中BMP/GTR组有大量新生牙槽骨、牙骨质、牙周韧带生长。对照组新生组织量很少。结论　β TCP/BMP是一种具有较强骨诱导能力 ,生物相容性较好的复合人工骨 ,在引导牙周组织再生术中有良好的应用前景     

引导组织和骨组织再生术及其生长因子在牙周骨缺损治疗中的应用

引导组织再生术和引导骨再生术广泛用于牙周骨缺损的治疗中,给牙周组织再生开辟了广泛的空间,但二者单独使用却存在一定的局限性。因此,目前的研究多趋向于将骨移植材料和膜材料与多肽生长因子联合应用于牙周骨缺损的修复。下面就引导组织再生膜材料、引导骨再生支架材料和碱性成纤维细胞生长因子的理化性质、生物学功能,以及三者联合应用于牙周骨缺损治疗中的作用作一综述。     

Periodontal tissue engineering and regeneration: Consensus Report of the Sixth European Workshop on Periodontology

Aim: To review the scientific preclinical background and clinical studies of current methods of periodontal regeneration in the treatment of infrabony defects and soft tissue deficiencies
Method: Five commissioned review papers including two systematic reviews were scrutinized by a group of experts in order to derive consensus conclusions, clinical relevance/implications and to propose future research requirements.
Results: The following five papers were assessed:
  1. Biological mediators and periodontal regeneration: a review of enamel matrix proteins at the cellular and molecular levels.
  2. Regeneration of periodontal tissues: combination of barrier membranes and grafting materials – Biological foundation and preclinical evidence.
  3. Clinical outcomes with bioactive agents alone or in combination with grafting or GTR
  4. Treatment of gingival recession with coronally advanced flap procedures. A systematic review.
  5. Soft tissue management at implant sites     

Maintenance of new attachment 1 and 4 years following guided tissue regeneration (GTR)

Abstract. The aim of the present study was to evaluate periodontal tissue alterations during the maintenance phase following GTR therapy. 18 patients (average age 54 years, range 39–79 years) with 19 local periodontal defects were monitored longitudinally using clinical periodontal parameters and radiographic assessments of bone level changes. 6 out of originally 24 patients were not available at the 4-year examination (2 patients were unwilling to participate and in 4 patients root amputations or tooth extractions had to be performed). Evaluations were perfomed at baseline. 3 months, 1 year and 4 years following GTR therapy (using non-resorbable Gore-Tex® Periodontal Material). The changes observed at the deepest site of each tooth treated by GTR were compared to those encountered in the entire dentition. Supportive periodontal therapy was performed according to the patient's individual needs between 3 and 12 times between the 1 and 4 years examination. The plaque index and the gingival index at the 4 years examination were assessed and had increased to almost double the value of baseline, although the BOP remained lower compared to baseline data. Between the 1 and 4 years examinations, 1.27 mm of clinical attachment was lost as a mean. Regarding the site of each tooth treated with GTR with the initially deepest probing pocket depth, 1.42 mm of clinical attachment was lost during the maintenace phase. However, compared to baseline data, 1.37 mm of new attachment could be maintained. The clinical attachment level was maintained within ±1 mm in 12 out of 19 sites during the 4 years of maintenance. At 7 sites, a loss between 2 and 5 mm occurred during the maintenance phase. Compared to the baseline values, 4 sites had lost ≥2 mm of clinical attachment resulting in a net loss. Between the 1 and 4 years observation, no significant change in bone height was observed. Multiple regression analyses showed correlations between the maintenance of the new attachment (expressed as change in probing attachment level) and a combination of factors such as number of recall visits during maintenance phase, age of the patient and % of loser sites in the corresponding dentitions. It was concluded that a low incidence of gingival inflammation was a. prerequisite for the maintenance of attachment levels gained by the GTR technique.     

生长因子智能控释与牙周组织再生

牙周骨移植、引导组织再生术（guided tissue regeneration，GTR）为牙周病的治疗和牙周缺损的修复带来了新的希望，但在恢复牙周组织的结构和功能方面还远不能达到理想的目标。组织工程和基因技术才刚刚起步，离临床应用还有较远的距离；药物控释技术的迅猛发展和活性牙周生物材料的研制与开发，为损害牙周组织结构功能的修复重建开辟了新的研究空间。     

Evaluation of a cell-permeable barrier for guided tissue regeneration combined with demineralized bone matrix

AIM: To evaluate whether bone formation by guided tissue regeneration (GTR) and demineralized bone matrix (DBM) can be enhanced by the use of a cell-permeable Teflon barrier allowing the penetration of undifferentiated mesenchymal cells from the surrounding soft tissues. MATERIAL AND METHODS: DBM was produced from the long bones of rats, and its bone-inductive properties were tested in three rats prior to the study by intramuscular implantation. Thirty, 4-month-old, male albino rats of the Wistar strain were used. Following surgical exposure of the mandibular ramus, a cell-permeable Teflon capsule, loosely packed with DBM, was placed with its opening facing the lateral surface of the ramus (test side). At the contralateral side, serving as control, a non-perforated (cell-occlusive) Teflon capsule, loosely packed with the same amount of DBM, was placed. After healing periods of 30, 60, and 120 days, groups of 10 animals were killed, and 40-70 microm thick undecalcified sections of the capsules were produced. RESULTS: Computer-assisted planimetric measurements on the histological sections disclosed similar amounts of newly formed bone in both test and control capsules. After 4 months, the new bone in the control capsules occupied 45.0% of the cross-sectional area of the capsule, while it was 50.5% in the test capsules. This difference was not statistically significant (P<0.05). CONCLUSION: Similar amounts of bone formed in cell-permeable and cell-occlusive capsules grafted with DBM, suggesting that invasion of undifferentiated mesenchymal cells from the surrounding soft tissues into the barrier-protected area is unnecessary for bone formation with GTR.     

Periodontal repair in dogs: effect of recombinant human transfornning growth factor-β1 on guided tissue regeneration

Abstract. This study evaluated alveolar bone and cementum regeneration following surgical implantation of recombinant human transforming growth factor- β₁ (rhTGF-β₁) in conjunction with guided tissue regeneration (GTR). Supraalvcolar, critical size, periodontal defects were surgically created around the 3rd and 4th mandibular premolar teeth in right and left jaw quadrants in 5 beagle dogs. Alternate jaw quadrants in consecutive animals received rhTGF-β₁ in a CaCO₃/ hydroxyethyl starch carrier with GTR, or carrier with GTR alone (control), 20μg of rhTGF-/A in buffer solution was incorporated into approximately 0.8 ml of carrier for each defect scheduled to receive rhTGF-β₁. Animals were sacrificed at week 4 postsurgery and tissue blocks were harvested and processed for histo-metric analysis. Clinical healing was generally uneventful. Minor membrane exposures were observed. Defects with membrane exposure displayed an inflammatory infiltrate underneath the membrane. Bone regeneration of trabecular nature, apparent in all animals, was generally limited to the very apical aspect of the defects. Cementum regeneration was limited without obvious differences between experimental conditions. Comparing rhTGF-β to control defects, statistically significant differences were found for area (1.8±0.4 and 1.3±0.6 mm², respectively: p<0.05) and density (0.3±0.1 and 0.2±0.03. respectively: p<0.05) of alveolar bone regeneration. Observed differences are small and represent a clinically insignificant potential for enhanced regeneration in this preclinieal model. Within the limitations of study, it may be concluded that rhTGF-β₁ has a restricted potential to enhance alveolar bone regeneration in conjunction with GTR.     

Prognostic factors for alveolar regeneration: effect of tissue occlusion on alveolar bone regeneration with guided tissue regeneration

OBJECTIVES: Design criteria for guided tissue regeneration (GTR) devices include biocompatibility, cell occlusion, space-provision, tissue integration, and ease of use. The objective of this study was to evaluate the effect of cell occlusion and space-provision on alveolar bone regeneration in conjunction with GTR. METHODS: Routine, critical-size, 6 mm, supra-alveolar, periodontal defects were created in 6 young adult Beagle dogs. Space-providing ePTFE devices, with or without 300-microm laser-drilled pores were implanted to provide for GTR. Treatments were alternated between left and right jaw quadrants in subsequent animals. The gingival flaps were advanced for primary intention healing. The animals were euthanized at week 8 post surgery. The histometric analysis assessed regeneration of alveolar bone relative to space-provision by the ePTFE device. RESULTS: A significant relationship was observed between bone regeneration and space-provision for defect sites receiving the occlusive (beta = 0.194; p < 0.02) and porous (beta = 0.229; p < 0.0004) GTR devices irrespective of treatment (p = 0.14). The bivariate analysis showed that both space-provision and device occlusivity significantly enhanced bone regeneration. Hence, sites receiving the occlusive GTR device and sites with enhanced space-provision showed significantly greater bone regeneration compared to sites receiving the porous GTR device (p = 0.03) or more limited space-provision (p = 0.0002). CONCLUSIONS: Cell occlusion and space-provision may significantly influence the magnitude of alveolar bone regeneration in conjunction with guided tissue regeneration.     

PGLA牙周引导组织再生片体外降解性能实验研究

目的：研究PGLA牙周引导组织再生片体外的降解周期，并对影响其降解动力学的各种因素作出评价。方法：通过质量损耗率、相对分子质量测定及形态学观察(电镜)等手段分别对PGLA牙周片在体外静态水溶液环境中的降解性能进行研究。结果：PGLA膜在体外的降解周期大约为9～10周。材料在模拟体液中的降解速率比在PBS溶液中快；降解介质pH值越大，材料质量损耗也越快；不同尺寸牙周片在各降解周期的质量损耗率均无显著性差异。结论：PGLA牙周引导组织再生片体外降解主要是化学降解过程，通过酯键的水解来进行。降解介质的不同和pH值的改变都会对材料降解动力学产生影响，而材料尺寸变化对降解过程不产生影响。