Clinical Efficacy of GBR Technique Combined with Temporary Bridgework-Guided Gingival Contouring in Treating Upper Anterior Tooth Loss with Labial Bone Defects

Objective:To investigate the clinical effect of the guided bone regeneration(GBR)technique combined with temporary bridgework-guided gingival contouring in treating upper anterior tooth loss with labial bone defects.Methods:From July 2023 to April 2024,80 patients with upper anterior tooth loss and labial bone defects were admitted to the hospital and selected as evaluation samples.They were divided into an observation group(n=40)and a control group(n=40)using a numerical table lottery scheme.The control group received treatment with the GBR technique,while the observation group received treatment with the GBR technique combined with temporary bridges to guide gingival contouring.The two groups were compared in terms of clinical red aesthetic scores(PES),labial alveolar bone density,labial bone wall thickness,gingival papillae,gingival margin levels,and patient satisfaction.Results:The PES scores of patients in the observation group were higher than those in the control group after surgery(P<0.05).The bone density of the labial alveolar bone and the thickness of the labial bone wall in the observation group were higher than those in the control group.The levels of gingival papillae and gingival margins were lower in the observation group after surgery(P<0.05).Additionally,patient satisfaction in the observation group was higher than in the control group(P<0.05).Conclusion:The GBR technique combined with temporary bridge-guided gingival contouring for treating upper anterior tooth loss with labial bone defects can improve the aesthetic effect of gingival soft tissue,increase alveolar bone density and the thickness of the labial bone wall,and enhance patient satisfaction.This approach is suitable for widespread application in healthcare institutions.

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.

Preparation and Characterization of Chitosan/β-GP Membranes for Guided Bone Regeneration

Bioabsorbable chitosan/β-glycerol phosphate （CS/β-GP） composite membranes were fabricated through a relatively PH neutral and mild sol-gel process for guided bone regeneration （GBR）.Their structural properties,morphology,and tensile strength were investigated.FTIR and XRD analyses indicated that there were chemical bonds between the CS andβ-GP.SEM analysis revealed that the CS/β-GP composite membranes had a porous structure both at the surface and in sublayers.Even though the incorporation ofβ-GP in the CS matrix decreased the initial tensile strength of the membrane,the CS/β-GP membranes were still fit for GBR application with their tensile strength of roughly 1MPa.The concentration ofβ-GP was proportional to the pore size and thickness but was inversely proportional to the tensile strength of the CS/β-GP membrane.The present findings indicate that,based on its characteristics,the CS/β-GP composite membrane is a potential bioresorbable membrane for use in guided bone regeneration.

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.

Improved guided bone regeneration by combined application of unmodified, fresh autologous adipose derived regenerative cells and plasma rich in growth factors:A first-in-human case report and literature review

BACKGROUND Novel strategies are needed for improving guided bone regeneration(GBR) in oral surgery prior to implant placement, particularly in maxillary sinus augmentation(GBR-MSA) and in lateral alveolar ridge augmentation(LRA). This study tested the hypothesis that the combination of freshly isolated, unmodified autologous adipose-derived regenerative cells(UA-ADRCs), fraction 2 of plasma rich in growth factors(PRGF-2) and an osteoinductive scaffold(OIS)(UAADRC/PRGF-2/OIS) is superior to the combination of PRGF-2 and the same OIS alone(PRGF-2/OIS) in GBR-MSA/LRA.CASE SUMMARY A 79-year-old patient was treated with a bilateral external sinus lift procedure as well as a bilateral lateral alveolar ridge augmentation. GBR-MSA/LRA was performed with UA-ADRC/PRGF-2/OIS on the right side, and with PRGF-2/OIS on the left side. Biopsies were collected at 6 wk and 34 wk after GBRMSA/LRA. At the latter time point implants were placed. Radiographs(32 mo follow-up time) demonstrated excellent bone healing. No radiological or histological signs of inflammation were observed. Detailed histologic,histomorphometric, and immunohistochemical analysis of the biopsies evidenced that UA-ADRC/PRGF-2/OIS resulted in better and faster bone regeneration than PRGF-2/OIS.CONCLUSION GBR-MSA with UA-ADRCs, PRGF-2, and an OIS shows effectiveness without adverse effects.

Silk Fibroin/Poly-L-lactide Lactone Bi-layered Membranes for Guided Bone Regeneration

After removal of the caries or diseased teeth,the alveolar ridge will undergo absorption and atrophy.When the amount of alveolar bone is insufficient,it will cause an inability to perform effective dental implant restoration.In order to control the absorption and promote the repair and regeneration of alveolar ridge,a method of implanting guided bone regeneration(GBR)membranes at the extraction site is often used.In this study,silk fibroin(SF)and poly-L-lactide lactone(PLCL)were used to prepare bilayered guided bone regeneration membranes,and its morphology,hydrophilicity,surface roughness and mechanical properties were studied.At the same time,the drug release behaviors and cell compatibility of the bilayered membranes were studied.The results showed that SF/PLCL bi-layered membranes had good mechanical properties and surface hydrophilicity,and the drug-loaded bi-layered membranes had good cell compatibility.The bilayered membranes fabricated in this study are of potential for applying in the oral health field to promote bone regeneration.

Enucleation combined with guided bone regeneration in small and medium-sized odontogenic jaw cysts

BACKGROUND The odontogenic jaw cyst is a cavity containing liquid,semifluid or gaseous components,with the development of the disease.In recent years,with the rapid development of oral materials and the transformation of treatment of jaw cysts,more options are available for treatment of postoperative bone defect of jaw cysts.Guided bone regeneration(GBR)places biomaterials in the bone defect,and then uses biofilm to separate the proliferative soft tissue and the slow-growing bone tissue to maintain the space for bone regeneration,which is widely used in the field of implantology.AIM To observe the clinical effect of GBR in repairing bone defect after enucleation of small and medium-sized odontogenic jaw cysts.METHODS From June 2018 to September 2020,13 patients(7 male,6 female)with odontogenic jaw cysts were treated in the Department of Oral Surgery,Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine.Adults without hypertension,heart disease,diabetes or other systemic diseases were selected.The diagnosis was based on the final pathological results:11 cases were diagnosed as apical cysts,one as primordial cyst,and one as dentigerous cyst.The lesions were located in the maxilla in seven cases,and in the mandible in six cases.All cases were treated with the same method of enucleation combined with GBR.RESULTS Three to four months after the operation,the boundary between the implant site and the surrounding normal stroma was not obvious in patients with small-sized odontogenic jaw cysts.The patients with tooth defects were treated with implant after 6 mo.For the patients with medium-sized odontogenic jaw cysts,the density of the center of the implant area was close to the normal mass at 6 mo after surgery,and there was a clear boundary between the periphery of the implant area and the normal mass.The boundary between the periphery of the implant area and the normal mass was blurred at 8-9 mo after surgery.Patients with tooth defects were treated with implants at>6 mo after the operation.CONCLUSION Enucleation combined with guided bone regeneration in small and medium-sized odontogenic jaw cysts can shorten the time of osteogenesis,increase the amount of new bone formation,reduce complications,and improve quality of life.

A Novel Guided Bone Regeneration Membrane Composed of Nano-hydroxyapatite and Aliphatic Polyester-amide

Hydrothermally synthesized nano-hydroxyapatite（n-HA ） varmg m wetght Jrom 10% to 30% was used us filler to make guided bone regeneration （ GBR ） composite membranes with navel aliphatic polyesteramide （ PEA ）. The structare and properties of PEA and its n- HA composites were investigated through TEM, IR, XRD, SEM and EDX. The shape and size of the n- HA crystals are similar to the apatite crystals in nataral bone. Molecule interactions are present between the n- HA and PEA in the compasite, which allows the uniform dispersion of n- HA in PEA matrix. This contributes enhanced mechanical property and bioactivhy to the compasite. The cytacompatibilhy of the composites has been investigated by culturing osteoblasts on the membranes. Good cell attachment and proliferation manner were observed on the membranes after 1 week. These results suggest that the PEA/ n-HA compasite membrane prepared in this study may serve us barrier membranes for guided bone regeneration and potential candidate scaffold for tissue engineering.

A Case Report of Immediate Implant Placement Combined with Flap Surgery,Guided Bone Regeneration and Non-submerged Healing with a Labial Bone Wall Defect in the Esthetic Zone

[Basckground]This case report presented a methodology for immediate implantation in the esthetic zone with a facial bone defect along with flap surgery,guided bone regeneration,and non-submerged healing.[Case presentation]A 27-year-old female patient was complaining of the aesthetic complication that was caused via metallic staining of the neck of ceramic crowns in the maxillary right anterior region for one year.She has experienced immediate implantation along with flap surgery,guided bone regeneration(GBR),and non-submerged healing.The torque of the implant reached to the 35 N·cm to confirm primary stability.Six months after surgery,the healing abutment and the implant were fixed,the gingiva was healthy in the surgical area,and the nearby teeth and the opposite teeth were normal.[Results]The results of cone-beam computer tomography(CBCT)revealed that bone defects were filled with the newly formed bone.At the same time,the final impressions accomplished,and an all-ceramic crown was fit-placed.As a whole,the patient satisfaction rate was high.[Conclusions]Immediate implant placement with flap surgery,GBR,and non-submerged healing with a facial bone wall defect in the esthetic zone is an achievable process.

Effect of concentrated growth factor combined with guided bone regeneration on cell proliferation and bone resorption in patients with severe periodontitis

Objective: To study the effect of concentrated growth factor (CGF) combined with guided bone regeneration on cell proliferation and bone resorption in patients with severe periodontitis. Methods: Patients with severe periodontitis who were treated in Stomatology Department of Shenmu Hospital between May 2014 and February 2017 were selected as the research subjects and randomly divided into two groups, surgery + CGF group received concentrated growth factor combined with guided bone regeneration, and pure surgery group received guided bone regeneration. The contents of inflammatory response, cell proliferation and bone resorption markers in gingival crevicular fluid were determined 1 week after treatment. Results: 1 week after treatment, HMGB1, ICAM1, E-selectin, Smac, FasL, Caspase-8, Caspase-9, Caspase-3, RANKL and NTX contents in gingival crevicular fluid of surgery + CGF group were significantly lower than those of pure surgery group while PD-L1, hBD-3, Wnt3a, BGP and OPG contents were significantly higher than those of pure surgery group. Conclusion:Concentrated growth factor combined with guided bone regeneration for severe periodontitis can inhibit inflammatory response, apoptosis and bone resorption, which is beneficial to the reconstruction of periodontal tissue.

Guided bone regeneration in long-bone defect with a bilayer mineralized collagen membrane

Bone regeneration for large,critical-sized bone defects remains a clinical challenge nowadays.Guided bone regeneration(GBR)is a promising technique for the repair of multiple bone defects,which is widely used in oral and maxillofacial bone defects but is still unsatisfied in the treatment of long bone defects.Here,we successfully fabricated a bilayer mineralized collagen/collagen(MC/Col)-GBR membrane with excellent osteoinductive and barrier function by coating the MC particles prepared via in situ biomimetic mineralization process on one side of a sheet-like pure collagen layer.The aim of the present study was to investigate the physicochemical properties and biological functions of the MC/Col film,and to further evaluate its bone regeneration efficiency in large bone defect repair.Fouriertransform infrared spectra and X-ray diffraction patterns confirmed the presence of both hydroxyapatite and collagen phase in the MC/Col film,as well as the chemical interaction between them.stereo microscope,scanning electron microscopy and atomic force microscope showed the uniform distribution of MC particles in the MC/Col film,resulting in a rougher surface compared to the pure Col film.The quantitative analysis of surface contact angle,light transmittance and tensile strength demonstrated that the MC/Col film have better hydrophilicity,mechanical properties,light-barrier properties,respectively.In vitro macrophage co-culture experiments showed that the MC/Col film can effectively inhibit macrophage proliferation and fusion,reducing fibrous capsule formation.In vivo bone repair assessment of a rabbit critical segmental radial defect proved that the MC/Col film performed better than other groups in promoting bone repair and regeneration due to their unique dual osteoinductive/barrier function.These findings provided evidence that MC/Col film has a great clinical potential for effective bone defect repair.

牙槽突扩张术联合GBR植骨术同期种植牙在牙齿发育异常患者中的应用效果

目的:探讨牙槽突扩张术联合骨引导再生(GBR)植骨术同期种植牙在牙齿发育异常患者中的应用效果。方法:纳入87例(94牙)牙齿发育异常患者为研究对象,根据治疗方式不同分为常规组(n=37,40牙)和GBR组(n=50,54牙)。常规组行牙槽骨劈开术治疗;GBR组行牙槽突扩张术联合GBR植骨术治疗,术后随访1年。比较两组患者治疗有效率、手术基本情况(手术时间、离院时间及骨愈合时间);术后1个月及6个月种植体稳定性[稳定系数(ISQ)];术后1年种植体周围软组织情况[红色美学标准(PES)评分]、种植体周围牙槽骨吸收值及种植体周围牙整齐度;手术并发症及术后1年修复体并发症发生情况。结果:GBR组患者治疗有效率高于常规组(P<0.05);骨愈合时间短于常规组(P<0.05);两组患者手术时间及离院时间比较,差异无统计学意义(P>0.05)。术后1个月及6个月,GBR组患者种植体ISQ高于常规组(P<0.05)。术后1年,GBR组患者种植体周围软组织PES评分、种植体周围牙槽骨吸收值、牙整齐度高于常规组(P<0.05)。两组患者手术并发症比较,差异无统计学意义(P>0.05);GBR组患者术后1年修复体并发症总发生率低于常规组(P<0.05)。结论:牙槽突扩张术联合GBR植骨术同期种植牙治疗有效率高,且牙齿发育异常患者预后效果更好。

基于Mimics三维重建比较自体块状骨移植和GBR在水平骨增量中的临床效果

目的:比较自体块状骨移植与引导骨再生(guided bone regeneration,GBR)在水平骨增量中的临床效果。方法:选择2019年6月—2021年6月于合肥市口腔医院行种植修复伴水平骨缺损的患者42例,随机分为2组。A组20例,采用自体块状骨移植;B组22例,采用GBR进行水平骨增量。评价2组患者并发症发生率、疼痛度、二次植骨率、骨宽度增量、骨吸收率、修复1年的边缘骨吸收量和种植成功率。采用SPSS 26.0软件包对数据进行统计学分析。结果:2组种植成功率、并发症发生率和二次植骨率无显著差异,疼痛度A组显著高于B组(P<0.05)。术后6个月嵴顶下2 mm骨宽度增量A组显著高于B组(P<0.05),而在嵴顶下6 mm和10 mm处,2组无显著差异;A组在嵴顶下2mm吸收率显著低于B组(P<0.05),在嵴顶下6 mm和10 mm处差异无统计学意义。2组修复1年后的边缘骨吸收量无显著差异。结论:对于水平向骨缺损,自体块状骨移植较GBR在嵴顶处可获得更佳的骨轮廓,修复1年后2组边缘骨吸收量接近。

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.

高模量高强度丝素蛋白GBR膜的制备及性能评估

目的拟制备一种高模量和高强度的可降解丝素蛋白引导骨再生(GBR)膜,以解决骨缺损修复成骨空间维持问题。方法提纯丝素蛋白后利用蒸发-热压法制备膜材,使用拉伸测试、体外模拟、细胞共培养等方法评估其理化性质与生物性能。结果制得丝素蛋白GBR膜,体外模拟12 h降解率为35.3%,湿态弹性模量达45 MPa,拉伸强度达8.39 MPa,7 d细胞生存率近100%。结论所制得可降解GBR膜具有高模量和高强度,以及优异的生物相容性,有望为解决骨缺损修复成骨空间维持问题提供材料基础。

Gene expression analysis of cytokines and MMPs in melatonin and rhBMP-2 enhanced bone remodeling

BACKGROUND In the medical and dental fields,there is a need for studies of new therapeutic approaches for the treatment of bone defects that cause extensive bone loss.Melatonin may be an important endogenous biological factor for bone remodeling,and growth factors may enhance the repair process.AIM To evaluate the gene expression of cytokines(IL-1β,IL-6,IL-10 and TNF-α),markers of osteoclastogenesis(RANK,RANKL and OPG)and MMPs(MMP-1,MMP-2,MMP-8 and MMP-13)from the treatment of melatonin associated with an osteogenic membrane and rhBMP-2 on the recovery of a bone injury.METHODS Sixty-four rats were used and divided into 9 experimental groups and were formed according to the treatment carried out in the region of the bone lesion,which varied between the combination of 1,10 and 100μmol/L of melatonin.Gene Expression analysis was performed using real time-PCR by reading the concentration of total RNA and reverse transcription.RESULTS There were differences between groups when compared with clot or scaffold control,and improvement with a higher concentration of melatonin or rhBMP-2.The combination melatonin(1μg)with 5μg of rhBMP-2,using the guided bone regeneration technique,demonstrated some effects,albeit mild,on bone repair of critical bone defects.CONCLUSION This indicates that the approach for administering these substances needs to be reassessed,with the goal of ensuring their direct application to the affected area.Therefore,future research must be carried out,seeking to produce materials with these ideal characteristics.

GBR术结合PRF治疗美学区前牙缺损的效果

目的探讨引导骨再生(GBR)术结合富血小板纤维蛋白(PRF)对美学区前牙缺损患者牙槽嵴骨量及牙槽骨骨密度的影响。方法以焦作煤业(集团)有限责任公司中央医院2017年1月至2021年12月诊治的美学区前牙缺损患者68例作为研究对象,按照随机分组原则,将以上患者分为研究组以及对照组,所有患者均接受前牙缺损区种植牙手术联合GBR术进行治疗,研究组患者在此基础上采取PRF进行治疗。比较两组患者的种植区牙槽骨骨壁厚度、术后6个月牙槽骨的吸收量、美学指标、外观美观性、牙槽骨密度之间的差异。结果治疗后,研究组患者的种植区1、7、10 mm处的牙槽骨骨壁厚度均高于对照组(P<0.05);研究组患者的美学指数评分高于对照组(P<0.05)。研究组患者的排列整齐、覆盖完整、咬合正常率高于对照组(P<0.05)。治疗后1、3、6个月,研究组患者的牙槽骨密度高于对照组(P<0.05)。结论美学区前牙缺损患者采取GBR术结合PRF引导骨再生治疗,患者牙槽嵴骨量、牙槽骨骨密度及美学指标显著改善,建议临床推广。

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.

Mg-based absorbable membrane for guided bone regeneration(GBR): a pilot study

A novel calcium-phosphate(Ca–P)-coated magnesium(Mg) membrane used for guided bone regeneration(GBR) was studied.The microstructural characterization, electrochemical test, immersion test,fluorescence labeling analysis and histopathological evaluation were carried out.The results showed that Ca–P coating could obviously improve the corrosion resistance of the pure Mg membrane.The in vivo results showed that Mg membrane coated with Ca–P would take 8 weeks to be completely absorbed.However, Mg membrane was completely absorbed within 1 week.Histopathological evaluation showed that the Ca–P-coated Mg membranes were significantly better than Ti membranes at the early implantation time(4 weeks), and with the time prolonging,the performance of the coated Mg membrane was not as good as pure Ti membranes(but still better than blank group) at 8 and 12 weeks.The coated biodegradable Mg membrane had a good promising application in GBR.But further studies have to be done to further decrease the degradation rate of pure Mg membrane.