Barrier Membranes for Guided Bone Regeneration (GBR): A Focus on Recent Advances in Collagen Membranes.

Guided bone regeneration (GBR) has become a clinically standard modality for the treatment of localized jawbone defects. Barrier membranes play an important role in this process by preventing soft tissue invasion outgoing from the mucosa and creating an underlying space to support bone growth. Different membrane types provide different biological mechanisms due to their different origins, preparation methods and structures. Among them, collagen membranes have attracted great interest due to their excellent biological properties and desired bone regeneration results to non-absorbable membranes even without a second surgery for removal. This work provides a comparative summary of common barrier membranes used in GBR, focusing on recent advances in collagen membranes and their biological mechanisms. In conclusion, the review article highlights the biological and regenerative properties of currently available barrier membranes with a particular focus on bioresorbable collagen-based materials. In addition, the advantages and disadvantages of these biomaterials are highlighted, and possible improvements for future material developments are summarized.

Guided bone regeneration with extracellular matrix scaffold of small intestinal submucosa membrane.

Guided bone regeneration (GBR) is a promising strategy for repairing bone defects using bioactive membranes. In this study, a new type of GBR membrane based on the small intestinal submucosa (SIS) was created, and its surface structure, cytological characteristics, and bone defect repair ability were compared with commonly used membranes. Our results show that compared to the Heal-all and Dentium membranes, the SIS membrane has an asymmetric structure that does not affect the proliferation of bone marrow mesenchymal stem cells (BMSCs). Instead, it increased their formation of calcium nodules and expression of bone morphogenetic protein-2 (BMP-2), alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2), and osteopontin (OPN). Six weeks after their insertion into a rat calvarial defect model, increased bone growth was observed in the SIS membrane group. Our results indicate that the SIS membrane has good biocompatibility and is more effective in promoting early bone formation than existing membranes. Given the wide range of source materials and simple preparation processes available, SIS membrane is a promising candidate for guided bone regeneration.

A bio-degradable synthetic membrane to treat superficial and deep second degree burn wounds in adults and children - 4 year experience.

INTRODUCTION: A new bio-degradable synthetic membrane was recently introduced to treat second degree burns in adults and pediatric patients. OBJECTIVE: To assess complications and outcomes using this absorbable synthetic membrane to treat second degree burns. METHODS: 229 burn patients, 138 pediatric, with superficial and deep second -degree wounds, treated with the absorbable synthetic membrane (Suprathel®, Polymedics, Denkendorf, Germany) were included in this study. Patients were treated under anesthesia or moderate sedation. The wound bed was prepared by using either rough debridement or dermabrasion excision. After hemostasis, the membrane was applied to the wound with an outer layer dressing of fatty gauze, bridal veil, absorptive gauze and an ACE® wrap. The outer dressing was removed every one to four days, depending on exudate, in order to closely follow the wound through the translucent membrane and fatty gauze layers. After complete epithelialization, the dressing separated and could be removed. The study focused on the need for subsequent grafting, healing time, patient pain level, hypertrophic scarring and rate of infection. RESULTS: All wounds in this study that were treated with Suprathel® healed without grafting. The average TBSA (Total Body Surface Area) was 8.9% (1%-60%). Average time to healing was 13.7 days for ≥ 90% epithelialization with 11.9 days for pediatric patients versus 14.7 days for adults. Throughout the treatment period, the average pain level was 1.9 on a 10-point scale. 27 patients developed hypertrophic scarring in some areas (11.7%). Average Length of stay (LOS) was 6.9 days. The rate of infection was 3.8% (8/229). Failure or progression to full thickness in part of the wounds was 5.2% (12/229). CONCLUSION: In treating second degree burn wounds, this membrane provides a simple, effective solution alternative with good outcomes and less pain than conventional and previously studied treatment options in the same institution. Fewer dressing changes and easier overall management of the wounds contribute to its favorable profile.

The Use of a Non-Absorbable Membrane as an Occlusive Barrier for Alveolar Ridge Preservation: A One Year Follow-Up Prospective Cohort Study.

：The aims of this study were to obtain preliminary data and test the clinical efficacy of a novel nonporous dense-polytetrafluoroethylene (d-PTFE) membrane (permamem®, botiss) in alveolar ridge preservation (ARP) procedures with a flapless approach. A traumatic extraction was performed in the premolar maxillary area, and a d-PTFE membrane was used to seal the alveolar cavity: no biomaterial was used to graft the socket and the membrane was left intentionally exposed and stabilized with sutures. The membrane was removed after four weeks and dental implants were placed four months after the procedure. The primary outcome variables were defined as the dimensional changes in the ridge width and height after four months. A total of 15 patients were enrolled in this study. The mean width of the alveolar cavity was 8.9 ± 1.1 mm immediately after tooth extraction, while four months later a mean reduction of 1.75 mm was experienced. A mean vertical reduction of 0.9 ± 0.42 mm on the buccal aspect and 0.6 ± 0.23 mm on the palatal aspect were recorded at implant placement. Within the limitations of this study, the d-PTFE membrane proved to be effective in alveolar ridge preservation, with the outcomes of the regeneration not affected by the complete exposure of this biomaterial.

Clinical study of guided bone regeneration with resorbable polylactide-co-glycolide acid membrane.

The guided bone regeneration (GBR) technique is often applied to provide sufficient bone for ideal implant placement. The objective of this study was to evaluate whether GC membrane®, which has already been used for guided tissue regeneration (GTR), can also be available for GBR. Twenty-three implants in 18 patients were evaluated in the study. All patients underwent implant placement with GBR using GC membrane®. Cone-beam computed tomography was performed at 13-30 weeks after surgery and the amount of augmented bone was assessed. The implant stability quotient (ISQ) was measured at the second operation to evaluate implant stability. Although wound dehiscence was observed at 4 of 23 regions (17.4%), all wounds closed quickly without any events by additional antibiotic administration. GBR-induced bone augmentation of 0.70-2.56 mm horizontally and 0-6.82 mm vertically. Only 0.18 mm of bone recession was observed at 16-24 months after implant placement. GBR with GC membrane® induced sufficient bone augmentation, leading to successful implant treatment. The present results suggest that GC membrane® is available not only for GTR, but also for GBR.

Effect of platelet-rich plasma on healing of class III furcation defects treated with autogenous bone grafting and guided tissue regeneration: a histomorphometric study in dogs / Efeito do plasma rico em plaquetas na reparação de lesões de furca classe III tratadas com enxerto ósseo autógeno e regeneração tecidual guiada: estudo histomorfométrico em cães

Objetivo: O objetivo deste estudo foi avaliar histologicamente os efeitos do plasma rico em plaquetas (PRP), quando usado em combinação com enxerto ósseo autógeno e membrana bioabsorvível (Resolut®) no tratamento de defeitos de furca Classe III em cães. Material e método: Cinco cães foram usados neste estudo. Defeitos de furca classe III (5 mm de altura e de profundidade) foram criados cirurgicamente no terceiro pré-molar inferior de ambos os lados. Nove semanas após a primeira cirurgia, os terceiros pré-molares foram tratados com raspagem e alisamento radicular e cada defeito recebeu um dos seguintes tratamentos: Enxerto ósseo autógeno + membrana (grupo C) ou PRP + enxerto ósseo autógeno + membrana (grupo T). Após um período de cicatrização de 90 dias, os animais foram sacrificados. Processamento histológico de rotina e coloração com hematoxilina e eosina e tricrômico de Masson foram realizados para determinar o efeito dos tratamentos na regeneração dos tecidos periodontais. Os dados foram analisados pelo teste T2 de Hotelling (p < 0,05). Resultado: A análise histomorfométrica da área de furca não mostrou nenhuma diferença estatisticamente significativa entre os grupos C e T. Os dois grupos de tratamento demonstraram resultados regenerativos semelhantes, com os defeitos de furca parcialmente preenchidos e a regeneração periodontal foi limitada à marca experimental apical das lesões. (p > 0,05). Conclusão: Dentro dos limites deste estudo, concluiu-se que o uso de PRP não melhorou a regeneração periodontal em defeitos de furca classe III tratados com enxerto ósseo autógeno e membrana bioabsorvível.

Objective: The purpose of this study was to evaluate the effects of the platelet-rich plasma (PRP) when used in combination with autogenous bone graft and bioabsorbable membrane (Resolut®) in the treatment of Class III furcation defects in dogs. Material and method: Class III furcation defects (5 mm in height and in depth) were surgically created in the mandibular third premolars of five mongrel dogs. After nine weeks, the lesions were treated with scaling and root planning and each defect received one of the following treatments: autogenous bone graft + membrane (group C) or PRP + autogenous bone graft + membrane (group T). After a healing period of 90 days, the animals were sacrificed. Routine histological processing and staining with hematoxilyn and eosin and Masson trichrome were performed and a histomorphometric analysis determined the effect of the treatments on periodontal tissue regereneration. Data were analyzed by Hotelling's T-squared (p < 0.05). Result: No statistically significant difference between C and T groups was observed by the histomorphometric analysis of the furcation area. Both treatment groups demonstrated similar regenerative results with the furcation defects partially filled and periodontal regeneration limited to the experimental notches of the lesions. (p > 0.05). Conclusion: According to the present results, PRP does not enhance the periodontal regeneration in class III furcation defects treated with autogenous bone graft and bioabsorbable membrane.

The Effect of beta-Tricalcium Phosphate and Deproteinized Bovine Bone on Bone Formation in the Defects of Rat Calvaria

An experimental study of absorbable membrane in prevention of tendon adhesion in chicken / 中华创伤骨科杂志

Objective To investigate the effect of absorbable membrane on prevention of tendon adhesion after the ruptured tendon is repaired. Methods In our experiment, 30 12-weeks-old Leghorn cocks were divided into 2 groups randomly. Group A was the blank group, and Group B was the absorbable membrane group. Each group had 15 cocks. The flexor tendon of third phalanx was made ruptured. After repairing, histological observation, failure mode test and functional recovery test were performed regularly. Results In Group B, there was little adhesion between tendon and normal tissue under gross observation. There was no significant tissue necrosis or scar tissue under microscope. There was no difference in the failure mode test between the 2 groups 6 weeks after repairing. The functions of movement of interphalangeal and metacarpophalangeal joints in group B were better than those in group A. Conclusion The absorbable membrane can be a kind of material or method used to prevent tendon adhesion.

A comparative study of the clinical effects of PRP and non-absorbable membrane in the treatment of mandibular class II furcations / 대한치주과학회지

This study was performed to compare the clinical effectiveness of two regenerative techniques for class II furcation involvements in human: a combination of bone grafts with PRP vs. GTR with bone grafts. The e-PTFE group was treated with non-absorbable membrane and bone grafts, the PRP group was treated with PRP and bone grafts Pocket depth, clinical attachment level, and gingival recession were measured at baseline and postoperative 6 months. Vertical and horizontal furcation depth were measured by re-entry surgeries at 6 months post-treatment Both groups were statistically analyzed by Wilcoxon signed Ranks Test & Mann-whitney Test using SPSS program (5% significance level). The results were as follows: 1. The change of pocket depth, clinical attachment level, vertical furcation depth and horizontal furcation depth in both groups was decreased significantly at 6 months than at baseline. (p<0.05) 2. The change of gingival recession in both groups was increased significantly at 6 months than at baseline. (p<0.05) 3. The change of alveolar crest absorption in both groups was increased at 6 months than at baseline but there were no statistically significant differences. 4. The change of pocket depth, clinical attachment level, vertical furcation depth and horizontal furcation depth in both groups was increased significantly at 6 months, but there were no statistically or clinically significant differences with both groups. 5. The change of gingival recession and alveolar crest absorption in both groups was increased at 6 months, but there were no statistically or clinically significant differences with both groups. In conclusion, the use of bone graft with PRP or GTR technique improved clinical index of the soft and hard tissue in mandibular class II furcation involvement but there were no statistically or clinically significant differences between bone graft with PRP and GTR technique.

Study On The Critical Maintenance Period Of Millipore Filter Membrane In Rats

The purpose of this study is to evaluate the critical maintenance period of absorbable membrane for guided bone regeneration. Fortynine Sprague-Dawley rats weighing about 300g were divided into seven groups. An 8 mm circular full-thickness defect in calvarial bone was made and then cellular acetate porous filter (Millipore filter(R)) was placed on the calvarial bone defect. The filter was removed at 2, 3, 4, 5, 6, 8 and 11 weeks after placement. Rats were sacrificed at 12 weeks the placement of cellular acetate porous filter. The specimens were stained with Hematoxylin-Eosin and observed under light microscope. The amount of regenerated bone was measured from both margin of calvarial bone defect (unit : mm). The results were as follows. Bone regeneration of each experimental group was increased gradually and the bond defect was almost completely filled with new bone in 5-, 6-, 8-, and 11-week experimental group. Histologic findings showed mild inflammatory response and granulation tissue formation without apparent adverse effects on the healing process. In 11-week experimental group, the bone defect was completely filled with new bone containing abundant osteoid which was oriented to the dural side and contribute to bony thickening. We suggest that non-absorbable membrane and bioabsorbable membrane presumably should remain intact for longer than 5 weeks to be effective.

Repair of cleft hard palate with absorbable membrane of poly-DL-lactic acid: A clinical report / 实用口腔医学杂志

Objective:To study the effects of poly-DL-lactic acid(PDLLA) biomembrane in the repair of cleft hard palate. Methods:Thirty-two cleft palate patients, age 2.67 to 12.83 years old, were treated. The traditional surgical method was used to close the cleft soft palate, and the PDLLA biomembrane was implanted into the surgical gap between the periosteum and bone at the hard palate and fixed with suture to close the cleft hard palate. Clinical follow-up was conducted for 6 months.Results:Operations on all 32 patients were completed successfully.The average surgical time was not prolonged, and post-operative complication was not increased. Wound healing of soft palate, uvula and hard palate was uneventful with no incidence of fistula or dehiscence. Conclusion: PDLLA absorbable biomembrane can be used to repair cleft hard palate.