Comparative study of chitosan/fibroin–hydroxyapatite and collagen membranes for guided bone regeneration in rat calvarial defects: micro-computed tomography analysis

This study aimed to utilize micro-computed tomography （micro-CT） analysis to compare new bone formation in rat calvarial defects using chitosan/fibroin-hydroxyapatite （CFB-HAP） or collagen （Bio-Gide） membranes. Fifty-four （54） rats were studied. A circular bony defect （8 mm diameter） was formed in the centre of the calvaria using a trephine bur. The CFB-HAP membrane was prepared by thermally induced phase separation. In the experimental group （n= 18）, the CFB-HAP membrane was used to cover the bony defect, and in the control group （n= 18）, a resorbable collagen membrane （Bio-Gide） was used. In the negative control group （n= 18）, no membrane was used. In each group, six animals were euthanized at 2, 4 and 8 weeks after surgery. The specimens were then analysed using micro-CT. There were significant differences in bone volume （BV） and bone mineral density （BMD） （P〈O.05） between the negative control group and the membrane groups. However, there were no significant differences between the CFB-HAP group and the collagen group. We concluded that the CFB-HAP membrane has significant potential as a guided bone regeneration （GBR） membrane.

Real-time-guided bone regeneration around standardized critical size calvarial defects using bone marrow-derived mesenchymal stem cells and collagen membrane with and without using tricalcium phosphate: an in vivo microcomputed tomographic and histologic e

The aim of the present real time in vivo micro-computed tomography （pCT） and histologic experiment was to assess the efficacy of guided bone regeneration （GBR） around standardized calvarial critical size defects （CSD） using bone marrow-derived mesenchymal stem cells （BMSCs）, and collagen membrane （CM） with and without tricalcium phosphate （TCP） graft material. In the calvaria of nine female Sprague-Dawley rats, full-thickness CSD （diameter 4.6 mm） were created under general anesthesia. Treatment-wise, rats were divided into three groups. In group 1, CSD was covered with a resorbable CM; in group 2, BMSCs were filled in CSD and covered with CM; and in group 3, TCP soaked in BMSCs was placed in CSD and covered with CM. All defects were closed using resorbable sutures. Bone volume and bone mineral density of newly formed bone （NFB） and remaining TCP particles and rate of new bone formation was determined at baseline, 2, 4, 6, and 10 weeks using in vivo pCT. At the lOth week, the rats were killed and calvarial segments were assessed histologically. The results showed that the hardness of NFB was similar to that of the native bone in groups I and 2 as compared to the NFB in group 3. Likewise, values for the modulus of elasticity were also significantly higher in group 3 compared to groups 1 and 2. This suggests that TCP when used in combination with BMSCs and without CM was unable to form bone of significant strength that could possibly provide mechanical ＂lock＂ between the natural bone and NFB. The use of BMSCs as adjuncts to conventional GBR initiated new bone formation as early as 2 weeks of treatment compared to when GBR is attempted without adiunct BMSC therapy.

In vitro and in vivo evaluations of Mg-Zn-Gd alloy membrane on guided bone regeneration for rabbit calvarial defect

To develop a biodegradable membrane with guided bone regeneration(GBR),a Mg-2.0Zn-1.0Gd alloy(wt.%,MZG)membrane with Ca-P coating was designed and fabricated in this study.The microstructure,hydrophilicity,in vitro degradation,cytotoxicity,antibacterial effect and in vivo regenerative performance for the membrane with and without Ca-P coating were evaluated.After coating,the membrane exhibited an enhance hydrophilicity and corrosion resistance,showed good in vitro cytocompatibility upon MC3T3E-1 cells,and exhibited excellent antibacterial effect against E.coli,Staphylococcus epidermis and Staphylococcus aureus,simultaneously.In vivo experiment using the rabbit calvarial defect model confirmed that Ca-P coated MZG membrane underwent progressive degradation without inflammatory reaction and significantly improved the new bone formation at both 1.5 and 3 months after the surgery.All the results strongly indicate that MZG with Ca-P coating have great potential for clinical application as GBR membranes.

Evaluation of Bone Regeneration of Simvastatin Loaded Chitosan Nanofiber Membranes in Rodent Calvarial Defects

Chitosan nanofiber membranes have been known to have a high degree of biocompatibility and support new bone formation with controllable biodegradation. The surface area of these membranes may allow them to serve as local delivery carriers for different biologic mediators. Simvastatin, a drug commonly used for lowering cholesterol, has demonstrated promising bone regenerative capability. The aim of this study was to evaluate simvastatin loaded chitosan nanofiber membranes for guided bone regeneration (GBR) applications and their ability to enhance bone formation in rat calvarial defects. Nanofibrous chitosan membranes with random fiber orientation were fabricated by electrospinning technique and loaded with 0.25 mg of simvastatin under sterile conditions. One membrane was implanted subperiosteally to cover an 8 mm diameter critical size calvarial defect. Two groups: 1) Control: non-loaded chitosan membranes;2) Experimental: chitosan membranes loaded with 0.25 mg of simvastatin were evaluated histologically and via micro-computed tomography (micro-CT) for bone formation at 4 and 8 weeks time points (n = 5/group per time point). Both groups exhibited good biocompatibility with only mild or moderate inflammatory response during the healing process. Histologic and micro-CT evaluations confirmed bone formation in calvarial defects as early as 4 weeks using control and experimental membranes. In addition, newly-formed bony bridges consolidating calvarial defects histologically along with partial radiographic defect coverage were observed at 8 weeks in both groups. Although control and experimental groups demonstrated no significant statistical differences in results of bone formation, biodegradable chitosan nanofiber membranes loaded with simvastatin showed a promising regenerative potential as a barrier material for guided bone regeneration applications.

Systematic evaluation of three porcine-derived collagen membranes for guided bone regeneration

Guided bone regeneration is one of the most common surgical treatment modalities performed when an additional alveolar bone is required to stabilize dental implants in partially and fully edentulous patients.The addition of a barrier membrane prevents non-osteogenic tissue invasion into the bone cavity,which is key to the success of guided bone regeneration.Barrier membranes can be broadly classified as non-resorbable or resorbable.In contrast to non-resorbable membranes,resorbable barrier membranes do not require a second surgical procedure for membrane removal.Commercially available resorbable barrier membranes are either synthetically manufactured or derived from xenogeneic collagen.Although collagen barrier membranes have become increasingly popular amongst clinicians,largely due to their superior handling qualities compared to other commercially available barrier membranes,there have been no studies to date that have compared commercially available porcine-derived collagen membranes with respect to surface topography,collagen fibril structure,physical barrier property,and immunogenic composition.This study evaluated three commercially available non-crosslinked porcine-derived collagen membranes(Striate+TM,Bio-Gide®and CreosTM Xenoprotect).Scanning electron microscopy revealed similar collagen fibril distribution on both the rough and smooth sides of the membranes as well as the similar diameters of collagen fibrils.However,D-periodicity of the fibrillar collagen is significantly different among the membranes,with Striate+TM membrane having the closest D-periodicity to native collagen I.This suggests that there is less deformation of collagen during manufacturing process.All collagen membranes showed superior barrier property evidenced by blocking 0.2–16.4µm beads passing through the membranes.To examine the immunogenic agents in these membranes,we examined the membranes for the presence of DNA and alpha-gal by immunohistochemistry.No alpha-gal or DNA was detected in any membranes.However,using a more sensitive detection method(real-time polymerase chain reaction),a relatively strong DNA signal was detected in Bio-Gide®membrane,but not Striate+TM and CreosTM Xenoprotect membranes.Our study concluded that these membranes are similar but not identical,probably due to the different ages and sources of porcine tissues,as well as different manufacturing processes.We recommend further studies to understand the clinical implications of these findings.

Appropriately adapted properties of hot-extruded Zn-0.5Cu-xFe alloys aimed for biodegradable guided bone regeneration membrane application

Appropriately adapted comprehensive mechanical properties,degradation behavior and biocompatibility are prerequisites for the application of Zn-based biodegradable implants.In this study,hot-extruded Zn-0.5Cu-xFe(x=0.1,0.2 and 0.4 wt%)alloys were fabricated as candidates for biodegradable materials for guided bone regeneration(GBR)membranes.The hot-extrusion process and Cu alloying were expected mostly to enhance the mechanical properties,and the Fe alloying was added mainly for regulating the degradation.The microstructure,mechanical properties and in vitro degradation behavior were systematically investigated.The ZnCuFe alloys were composed of a Zn matrix and FeZn13 phase.With increasing Fe content,a higher FeZn13 phase precipitation with larger particles was observed.Since elongation declined significantly until fracture with increasing Fe content up to 0.4 wt%,the ZnCuFe(0.2 wt%)alloy achieved a good balance between mechanical strength and ductility,with an ultimate tensile strength of 202.3 MPa and elongation at fracture of 41.2%.Moreover,the addition of Fe successfully accelerated the degradation of ZnCuFe alloys.The ZnCuFe(0.2 wt%)alloy showed relatively uniform corrosion in the long-term degradation test.Furthermore,extracts of the ZnCuFe(0.2 wt%)alloy showed no apparent cytotoxic effects against L929 fibroblasts,Saos-2 osteoblasts or TAg periosteal cells.The ZnCuFe(0.2 wt%)alloy exhibited the potential to inhibit bacterial adhesion of Streptococcus gordonii and mixed oral bacteria.Our study provides evidence that the ZnCuFe(0.2 wt%)alloy can represent a promising material for the application as a suitable GBR membrane.

作为GBR屏障膜的新型胶原膜的体内植入效果分析

目的探讨Ⅰ型胶原和矿化Ⅰ型胶原合成的胶原膜作为GBR屏障膜在动物体内植入后,诱导早期膜下成骨的能力。方法实验于2013年10月—2014年3月在沈阳军区总医院动物实验中心完成。选取小型巴马猪双侧下颌骨,分别于下颌骨骨体处用牙科裂钻制备8 mm×8 mm全层骨缺损3个,分别应用实验胶原膜覆盖、Bio-gide@覆盖、无覆盖膜骨缺损区。术后1个月处死动物,在处死前1、2周分别肌肉注射四环素溶液与二甲酚橙溶液。固定样本后,制备硬组织切片。分别在荧光显微镜及光学显微镜下(甲苯胺蓝、亚甲基蓝-酸性品红染色)观测膜的降解程度及膜下新骨生成能力,评价材料膜下骨形成量和骨成熟程度。结果实验组胶原膜具备良好的屏障作用,膜下新生骨矿化程度良好;骨小梁排列整齐,但新生骨量少于Bio-gide@覆盖组;无覆盖膜骨缺损区新生骨组织骨小梁排列混乱,新生骨量少。结论新型胶原膜在1个月时体内无明显降解,具备良好的膜下成骨能力,下一步需进行实验组胶原膜的改性,以增加胶原膜膜下成骨量。

新型GBR胶原膜的早期动物体内植入实验研究

目的：探讨新型国产GBR胶原膜体内植入后,诱导早期膜下成骨的能力。方法：实验于2013年10月~2014年3月在沈阳军区总医院动物实验中心完成。选取小型巴马猪,于双侧下颌骨骨体处用牙科裂钻制备8mm×8mm全层骨缺损3个,分别应用实验胶原膜、Bio-gide@、无覆盖膜覆盖骨缺损。术后1个月处死动物,分别在处死前1、2周分别肌肉注射四环素溶液与二甲酚橙溶液。固定样本后,制备硬组织切片。分别在荧光显微镜及光学显微镜下（甲苯胺蓝、亚甲基蓝-酸性品红染色）观测膜的降解程度及膜下新骨生成能力,评价材料膜下骨形成量和骨成熟程度。结果：实验组胶原膜具备良好的屏障作用,膜下新生骨矿化程度良好;骨小梁排列整齐,但新生骨量少于对照组。结论：新型国产胶原膜在1个月时无明显降解,具备良好的膜下成骨能力,需进行实验组胶原膜的改性,以增加膜下成骨量。

摩尔比对三元共聚物和GBR膜的性能影响

本研究合成了一系列不同摩尔比的丙交酯/乙交酯/三亚甲基碳酸酯(DLLA/GA/TMC)三元共聚物(PLGTMC),并用于制备引导骨再生(GBR)可吸收膜。通过凝胶渗透色谱和核磁氢谱对共聚物进行表征,并进行差示扫描量热、X-射线衍射和拉伸测试,研究了摩尔比对共聚物和GBR膜热性能、结晶性能和力学性能的影响。结果表明共聚物和GBR膜玻璃化转变温度和拉伸强度随TMC含量增加呈现降低趋势,结晶性和断裂伸长率随TMC含量增加呈现增加趋势,其中TMC含量为25%的GBR膜有望用于下一步的动物及临床试验。

可吸收胶原膜在颊侧袋形瓣引导性骨再生手术中的作用:一项回顾性影像学队列研究

目的:在颊侧袋形瓣引导性骨再生手术基础上,探讨放置可吸收胶原膜是否有利于维持术后牙槽嵴轮廓稳定。方法:收集2019年6月至2023年6月因单颗后牙缺失采用种植体植入同期进行颊侧袋形瓣引导性骨再生手术患者,根据骨粉表面是否覆盖胶原膜分为胶原膜覆盖组和无覆盖组。术前(T0)、术后即刻(T1)和术后3~7个月(T2)拍摄锥形束CT,利用Mimics软件测量种植体光滑-粗糙交界面下不同水平(0、2、4和6 mm)处颊侧骨板厚度(thickness of the buccal bone plate,BBT,分别表示为BBT-0、-2、-4、-6)。结果:收集胶原膜覆盖组15例,无胶原膜覆盖组14例,共计29例患者进行统计分析。在T0、T1和T2三个时间点,不同水平的BBT在两组间差异均无统计学意义(P>0.05)。T2时,BBT-0在胶原膜覆盖组和无覆盖组分别为(1.22±0.55)mm和(1.70±0.97)mm,相应的BBT-2分别为(2.32±0.94)mm和(2.57±1.26)mm。T1~T2愈合阶段不同水平处颊侧骨板吸收的绝对值[(0.47±0.54)~(1.33±0.75)mm]和百分数[(10.04%±24.81%)~(48.43%±18.32%)],以及T0~T2阶段颊侧骨板新骨形成厚度[(1.27±1.09)~(2.75±2.15)mm]在两组间差异均无统计学意义。结论:颊侧袋形瓣引导骨再生手术无论是否使用胶原膜均可有效修复种植体颈部颊侧骨缺损。与无胶原膜覆盖相比,胶原膜覆盖植骨材料不能提高术后牙槽嵴轮廓的稳定性。

交联型可吸收胶原膜应用于拔牙同期引导骨再生的临床研究

目的 评价戊二醛交联型胶原膜(glutaraldehyde cross-linked collagen membrane, GCM)应用于拔牙同期引导骨再生术的临床效果,并与非交联天然胶原膜(natural collagen membrane, NCM)进行比较。方法 采用前瞻性、随机、盲态评价、阳性对照、非劣效检验临床试验。在拔牙同期引导骨再生术后即刻(基线)和12周后通过CBCT测量牙槽嵴高度和宽度。通过基线的视觉模拟量表评分对膜的可操作性和稳定性进行临床评价。术后16周组织学观察牙龈及骨组织中膜的降解。结果 GCM组与NCM组分别有44例和38例受试者完成试验,两组牙槽嵴高度变化量分别为(0.88±0.62)mm和(0.82±0.81)mm;牙槽嵴宽度变化量分别为(0.71±0.72)mm和(0.95±0.86)mm,两组的影像学评价组间差异无统计学意义(P> 0.05)。操作性及稳定性的VAS评分两组之间存在显著性差异(P<0.05)。仅在GCM组中观察到部分结构完整的胶原膜。结论 戊二醛交联型胶原膜应用于拔牙同期引导骨再生的成骨效果与非交联天然胶原膜无差异,其临床操作性、稳定性及降解速率优于非交联天然胶原膜。

胶原膜在引导骨再生技术中的应用和改良研究进展

胶原蛋白是哺乳动物体内最丰富的蛋白质,将其作为主要材料制成的生物膜具有良好的理化性质和生物学功能,被广泛用于骨组织工程等医学领域。在引导骨再生技术中,以胶原膜作为可吸收屏障膜被广泛应用,但仍存在降解不可控、机械强度低等缺陷。为了改进这些不足,通过交联、矿化、表面修饰等方法,新型胶原膜的不断开发和应用成为该领域未来的发展趋势。本文就胶原膜在引导骨再生技术中的应用和改良进行综述,以期为新型胶原膜的研发提供新的思路。

可吸收性胶原膜结合无机牛骨修复种植牙骨缺损的临床研究

目的 :应用可吸收性生物膜Bio -gide结合无机牛骨Bio -oss修复临床牙种植中的骨缺损 ,解决种植区的骨量不足问题。方法 :在牙种植外科中将Bio -oss充填在暴露的种植体周围 ,表面覆盖可吸收性胶原膜Bio -gide ,6个月后进行二期手术 ,暴露骨缺损区 ,观察并测量骨缺损的修复情况 ,并通过临床检查及X线曲面断层片 ,评价其在临床种植体周围骨缺损中引导骨组织再生的效果。结果 :二期手术发现骨缺损区都获得了高水平的新骨形成 ,骨缺损重建百分率达 90 %。术后及承载 6～ 3 6个月的跟踪随访 ,结果显示 88个植入骨缺损区的ITI种植体 ,有 2颗脱落 ,种植体存活率达 97%。结论 :Bio -oss与Bio -gide联合应用于临床ITI种植体周围骨缺损 ,可以成功的引导骨组织再生 ,重建缺损的骨组织 。

Bio-oss结合Bio-gide修复牙种植体周围骨缺损的组织学研究

目的:通过制作带有种植体的硬组织磨片,评价无机牛骨(deproteinizednaturalbovinemineral,Bio-oss)结 合可吸收性胶原膜(bioresorbablecollagenmambrane,Bio-gide)在牙种植体周围骨缺损中的引导骨再生作用及效 果。方法:在兔股骨植入羟基磷灰石涂层BLB种植体,并在其外侧壁制造标准骨缺损,A组在骨缺损处植入Bio- oss颗粒并在其表面覆盖Bio-gide膜,B组作为空白对照,分别于术后1、2、4、6个月取样品,通过带种植体的硬组 织切片进行骨组织形态学分析。结果:术后1个月Bio-oss颗粒表面有新骨形成,随时间延长Bio-oss发生降解 吸收,新生骨量增加,并与种植体表面形成骨性结合。结论:可吸收性胶原膜Bio-gide结合Bio-oss应用于牙种 植体周围骨缺损中,可以引导骨组织再生,重建缺损的骨组织,新生骨与种植体形成骨性结合。

胶原膜联合自体骨髓基质细胞及富血小板血浆修复牙槽骨缺损的实验研究

目的初步探讨胶原膜与骨髓基质细胞(bone marrow stromal cells,BMSCs)、富血小板血浆(plateletrich plasma,PRP)复合后修复牙槽骨缺损的应用潜能。方法将犬BMSCs与BME-10X胶原膜复合培养。取3只雄性杂种犬,拔除双侧上下颌第1、2前磨牙,保留唇舌侧牙槽嵴,制备一近远中向15mm×5mm,冠根向8mm的骨内缺损,随机分为四组。A组(空白对照组):直接缝合牙龈;B组:缺损区上覆盖Bio-Gide胶原膜;C组:缺损区植入BMSCs胶原膜复合物后覆盖Bio-Gide胶原膜;D组:缺损区注入PRP,覆盖Bio-Gide胶原膜。分别于术后4、8、12周进行大体、X线片和组织学观察。结果BMSCs与胶原膜复合培养1d,细胞近似圆形或短梭形,3d左右可见多数细胞有突起,呈多边形及长梭形。大体观察:术后4周A组见骨缺损中央有明显凹陷,骨缺损区内见明显血肿机化物;B、C及D组骨缺损区主要为新生骨样组织充填,间杂少量血肿机化物。8周A组见骨缺损区凹陷基本长平,骨缺损顶部为纤维组织,血肿机化物被新生骨组织所取代;B、C及D组膜边缘破裂,与深面组织稍粘连,针头均不能刺入骨缺损表面。12周各组骨缺损区凹陷完全长平,A组牙槽嵴顶部纤维组织较其他组厚。X线片观察:各组骨质均长满骨缺损区;A、B、C及D组灰度值,4周分别为68、50、56及49,8周时为46、30、24及30,12周时为24、17、15及20。组织学观察:术后4周,A组缺损区可见大量纤维结缔组织及及新生血管形成的肉芽组织,未见明显新骨生成;B、C及D组膜的胶原结构均存在,其内侧面有新骨生成。8周A组缺损区新生骨小梁呈团灶状、网状;B、C及D组膜的胶原结构不完整,多个骨岛和少量纤维结缔组织连接整个骨缺损区。12周各组骨缺损区均被新生骨充填。结论使用胶原膜引导骨再生(guided boneregeneration,GBR)技术可促进牙槽骨缺损区成骨,将骨修复时间缩短为8周,但单独应用GBR的成骨作用与胶原膜复合BMSCs或PRP的成骨作用差异不明显,提示二者与GBR的联合应用还有待进一步研究。

可吸收性胶原膜引导即刻植入种植体周围骨组织再生的实验研究

目的探讨可吸收性胶原膜引导即刻植入种植体周围骨组织再生的效果。方法在12只成年杂种狗下颌第3、4前磨牙新鲜拔牙创即刻植入种植体的近中形成3mm×3mm×5mm骨缺损区,按自身同期对照研究设计,右侧为实验侧,骨缺损区上覆盖Co膜;左侧为空白对照侧,骨缺损区不覆盖Co膜。术后1、2、4、6个月分别处死一组动物,摘取下颌骨,采用大体观察、X线摄片、组织学观察、扫描电镜及生物力学(拔出实验)测定等方法检测缺损区骨组织再生的情况。结果实验侧种植体周围骨缺损区较空白对照侧新骨形成量多、外形好、骨成熟时间早,加速了骨组织的再生过程。结论可吸收性胶原膜具有良好的生物相容性和可降解性,可用作骨组织引导再生膜,以期促进骨缺损的再生修复,其促进作用主要表现在骨组织愈合的早期。

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。

钛膜和胶原膜联合应用引导种植体周骨缺损骨再生的临床研究

目的:评价钛膜与胶原膜联合应用引导种植体骨缺损骨再生的临床效果。方法:将34颗种植体植入30例患者的狭窄形牙槽嵴或唇颊骨壁缺损拔牙窝,所有种植体的唇、颊侧面部分暴露,种植体周骨缺损空间维持能力较差。测量种植暴露部分的最大长度,将羟基磷灰石珊瑚骨粉置于骨缺损处,采用钛膜覆盖稳定骨移植材料,然后将胶原膜覆盖于钛膜表面,无张力缝合伤口,术后6个月行Ⅱ期手术,取下钛膜,检查骨缺损骨再生的状况,再次测量种植暴露部分的最大长度。结果:2例患者于手术3个月左右因钛膜局部暴露,将钛膜取出。钛膜暴露率为6.6%。术后6个月Ⅱ期手术时见,所有种植体暴露部分完全被再生骨覆盖,种植体暴露部分长度为0。结论:在空间维持能力较差的骨缺损处,钛膜和胶原膜联合应用引导骨再生可获得理想结果。钛膜和胶原膜联合应用可显著降低钛膜的暴露率,延迟发生膜暴露的时间,从而使引导骨再生的结果更加具有可预测性。

膜引导骨再生技术在上前牙美学区牙种植手术中的临床应用研究

目的:评价膜引导骨再生技术在上前牙美学区牙种植中的临床应用效果。方法:选择16例上颌前牙缺失伴骨缺损患者,植入Ankyl os种植体22颗(其中即刻种植5颗),在骨缺损区植入珊瑚羟基磷灰石骨粉,应用可吸收胶原膜18块、钛膜4块,进行引导骨再生,重建牙槽骨的形态,术后4～6个月暴露种植体,最终完成烤瓷冠修复,二期手术时根据成骨情况评估成骨效果。结果:所有病例术后均随访6个月以上,除2颗失败外,其余20颗种植体均获得良好的骨修复效果,种植修复完成后取得较好的美学效果。结论:膜引导骨再生技术可以保存和重建上前牙牙槽嵴区软硬组织的外形,获得良好的美学效果。

纳米羟基磷灰石／壳聚糖复合膜的制备和表征

以壳聚糖(chitosan,CS)为高分子相,纳米羟基磷灰石(nano-hydroxyapatite,n-HA)为无机相,采用溶液共混和真空下溶剂挥发的方法制备了n-HA/CS复合膜,通过SEM、XRD、FTIR、接触角及力学性能等测试对此复合膜进行分析和表征。结果表明,复合膜具有非对称结构,上表面组分主要是CS,下表面组分是n-HA和CS复合体,并在底部形成了一层致密层,中间是疏松层;复合膜中CS与HA之间存在一定的化学键合并复合均匀,没有明显的相分离,且复合膜中的HA为类似于自然骨矿物相的弱结晶结构。复合膜的非对称结构对其接触角也有一定的影响,反映了膜表面亲、疏水性的不同,为细胞的粘附和旺长提供了一定的微环境。复合膜干态下的拉伸强度和断裂伸长率较纯CS膜的低,而在湿态时却较纯CS膜高。