Non-resorbable Membranes Research Articles

Immunological Response to Nonresorbable Barrier Membranes Used for Guided Bone Regeneration and Formation of Pseudo Periosteum: a Narrative Review.

Here we review the knowledge on the local biological immunological response (formation of "pseudo periosteum" of the host) to two types of nonresorbable membranes used in the horizontal and vertical alveolar ridge augmentation: the titanium-reinforced polytetrafluoroethylene membrane and the titanium mesh membrane. A literature search was conducted including available in vitro, in vivo, and clinical studies on cellular and molecular immunological response to these two types of nonresorbable membranes, in particular the formation of "pseudo periosteum".

Histological Evaluation of Guided Bone Regeneration in Osseous Defects Using A Novel Non-Resorbable Membrane

BACKGROUND: Guided bone regeneration and guided tissue regeneration procedures have been performed using barrier membranes in clinical dentistry to enhance bone formation in osseous defects, ridge preservation and reconstruction. Despite the considerable number of new biomaterials that develop with more advantages and fewer disadvantages for bone regeneration, the cost and surgical approach difficulties are still the main obstacles that we tried to overcome using the novel membrane. AIM: Our research aimed to assess histologically the bone formation using the novel membrane in experimental bone defects. MATERIAL AND METHODS: Our study was conducted on ten mongrel dogs. Each animal presented two groups. The first group was at the left side of the animal mandible which received Bio-Oss only while the right side received Bio-Oss and was covered by the novel non-resorbable membrane. These dogs were sacrificed (3, 6, 9 and 12 weeks) postoperatively for histological assessment of healing and bone formation of osseous defects. RESULTS: The histological evaluation showed that the formation of new bone in group I (Bio-OSS only) was less in amount as compared with group II (Bio-Oss with the novel non-resorbable membrane). CONCLUSION: The present clinical findings revealed that the novel non-resorbable membrane was inert and induced no inflammatory reaction or graft rejection. The study provided histological evidence of new bone formation in close contact with host bone due to osteoconductivity of Bio-Oss and cell occlussiveness of the membrane.

Classification Based on Extraction Socket Buccal Bone Morphology and Related Treatment Decision Tree.

Background: Alveolar ridge preservation (ARP) can successfully reduce volumetric ridge changes. However, there is still no consensus on what technique is the most advantageous for each specific clinical scenario. Hence, the aim of the present paper was to provide a treatment decision tree to guide the choice of predictable ARP procedures based on extraction socket buccal bone morphology and integrity. Material and Methods: Three socket types (ST) are proposed and discussed based on buccal bone morphology (intact, dehiscence or fenestration). Results: A decision tree for ARP was developed in order to merge ST classification with suitable treatment modalities. In the decision tree, the issue of when to allow unassisted healing or ARP was discussed. Described methods included bone grafting and collagen plug, and absorbable membrane or non-resorbable membrane, with or without flap elevation. Conclusion: A decision tree for ARP procedures was provided to guide clinicians towards the most conservative and predictable treatment approach based on remaining socket anatomical structures after extraction.

The efficiency of PRF, PTFE, and titanium mesh with collagen membranes for vertical alveolar bone addition in dental implant therapy: A narrative review

Aim: In prosthodontics, adequate bone volume is required to place a dental implant. Augmentation treatment can increase bone volume if it is insufficient. The guided bone regeneration (GBR) approach can be applied for either horizontal or vertical alveolar ridge augmentation. The GBR approach requires material in the form of a membrane to prevent non-osteogenic cells from accessing the wound, thus preventing any disruption of the process of new bone creation. Typically, non-resorbable membranes like titanium mesh are used in the GBR procedure to augment bone vertical dimension volume. In order to improve healing and bone regeneration, titanium mesh can be coupled with several membranes, including collagen membranes, platelet-rich fibrin (PRF), and polytetrafluoroethylene (PTFE). This review sought to ascertain the effects of adding vertical bone to titanium mesh following GBR with a collagen membrane, PRF, and PTFE for dental implant treatment. Materials and Methods: In this review, the medical literature on membrane titanium mesh used for implant therapy with the GBR technique was gathered from journals and publications published in the PubMed and Google Scholar databases between 2015 and 2020. Experimental research, case reports, and randomized clinical trials (RCTs) were included. The keywords used were “titanium mesh membrane, titanium mesh guided bone regeneration, titanium mesh with collagen membranes, titanium mesh with PRF, and PTFE. Results: Thirteen publications were found and chosen which discuss the usage of titanium mesh in conjunction with collagen membranes, PRF, and PTFE as barrier membranes for GBR. Conclusion: The GBR technique, which combines titanium mesh with PTFE and collagen membranes, can improve alveolar bone vertical addition, and the combination of titanium mesh with PRF can help the healing process move faster.

Biodegradable magnesium barrier membrane used for guided bone regeneration in dental surgery

Barrier membranes are commonly used as part of the dental surgical technique guided bone regeneration (GBR) and are often made of resorbable collagen or non-resorbable materials such as PTFE. While collagen membranes do not provide sufficient mechanical protection of the covered bone defect, titanium reinforced membranes and non-resorbable membranes need to be removed in a second surgery. Thus, biodegradable GBR membranes made of pure magnesium might be an alternative. In this study a biodegradable pure magnesium (99.95%) membrane has been proven to have all of the necessary requirements for an optimal regenerative outcome from both a mechanical and biological perspective. After implantation, the magnesium membrane separates the regenerating bone from the overlying, faster proliferating soft tissue. During the initial healing period, the membrane maintained a barrier function and space provision, whilst retaining the positioning of the bone graft material within the defect space. As the magnesium metal corroded, it formed a salty corrosion layer and local gas cavities, both of which extended the functional lifespan of the membrane barrier capabilities. During the resorption of the magnesium metal and magnesium salts, it was observed that the membrane became surrounded and then replaced by new bone. After the membrane had completely resorbed, only healthy tissue remained. The in vivo performance study demonstrated that the magnesium membrane has a comparable healing response and tissue regeneration to that of a resorbable collagen membrane. Overall, the magnesium membrane demonstrated all of the ideal qualities for a barrier membrane used in GBR treatment.

Hard tissue stability after guided bone regeneration: a comparison between digital titanium mesh and resorbable membrane

Guided bone regeneration (GBR) uses resorbable and non-resorbable membranes as biological barriers. This study compared the differences in hard tissue stability between GBR using evidence-based digital titanium mesh and resorbable collagen membranes during implant placement. A total of 40 patients (65 implant sites) were enrolled and divided into two groups: resorbable membrane and digital titanium mesh groups. The alveolar bone was analyzed at two- and three-dimensional levels using cone-beam computed tomography and by reconstructing and superimposing the hard tissues at four time points: preoperatively, postoperatively, before second-stage surgery, and 1 year after loading. The use of digital titanium mesh showed less alveolar bone resorption in vertical and horizontal directions two-dimensionally before the second-stage surgery and 1 year after loading. Regarding volumetric stability, the percentage of resorption after 6 months of healing with resorbable membrane coverage reached 37.5%. However, it was only 23.4% with titanium mesh. Although postoperative bone volume was greater at all labial sites with resorbable membrane than with digital titanium mesh, after substantial bone resorption within 1 year of loading, the labial bone thickness at the upper part of implants was thinner with resorbable membrane than with digital titanium mesh. Furthermore, digital titanium meshes made according to ideal bone arch contour reduced soft tissue irritation, and the exposure rate was only 10%. Therefore, although both resorbable membrane and digital titanium mesh in GBR were able to successfully reconstruct the bone defect, digital titanium meshes were better at maintaining the hard tissue volume in the osteogenic space.

Photocrosslinkable Col/PCL/Mg composite membrane providing spatiotemporal maintenance and positive osteogenetic effects during guided bone regeneration

Guided bone regeneration membranes have been effectively applied in oral implantology to repair bone defects. However, typical resorbable membranes composed of collagen (Col) have insufficient mechanical properties and high degradation rate, while non-resorbable membranes need secondary surgery. Herein, we designed a photocrosslinkable collagen/polycaprolactone methacryloyl/magnesium (Col/PCLMA/Mg) composite membrane that provided spatiotemporal support effect after photocrosslinking. Magnesium particles were added to the PCLMA solution and Col/PCLMA and Col/PCLMA/Mg membranes were developed; Col membranes and PCL membranes were used as controls. After photocrosslinking, an interpenetrating polymer network was observed by scanning electron microscopy (SEM) in Col/PCL and Col/PCL/Mg membranes. The elastic modulus, swelling behavior, cytotoxicity, cell attachment, and cell proliferation of the membranes were evaluated. Degradation behavior in vivo and in vitro was monitored according to mass change and by SEM. The membranes were implanted into calvarial bone defects of rats for 8 weeks. The Col/PCL and Col/PCL/Mg membranes displayed much higher elastic modulus (p < 0.05), and a lower swelling rate (p < 0.05), than Col membranes, and there were no differences in cell biocompatibility among groups (p > 0.05). The Col/PCL and Col/PCL/Mg membranes had lower degradation rates than the Col membranes, both in vivo and in vitro (p < 0.05). The Col/PCL/Mg groups showed enhanced osteogenic capability compared with the Col groups at week 8 (p < 0.05). The Col/PCL/Mg composite membrane represents a new strategy to display space maintenance and enhance osteogenic potential, which meets clinical needs.

Rehabilitation of Atrophic Posterior Mandible with Vertical Ridge Augmentation with Resorbable Membrane: Case Report with 3-Year Follow-up

Background: The placement of implants in the posterior mandible with the vertical bone defect can be associated with inadequate crown height space. Therefore, the vertical bone reconstruction of these defects is often necessary, although this procedure is technically challenging. Methods: A 49-year-old patient attended a private dental office for rehabilitation of an atrophic posterior mandible. The clinical and tomographic findings show absence of teeth #36, #37, #46, #47, and #48 with severe atrophy. Vertical bone augmentation was performed by using the guided bone regeneration technique with pericardium resorbable membrane followed by placement of short implants. The free gingival graft was performed, and after three months, screw-retained lithium disilicate single ceramic crowns were manufactured. Results: After a 3-years follow-up, bone loss around the implants or presence of gingival inflammation was not observed, and the prosthesis adaptation was found to have no alteration either. Therefore, aesthetics, as well as masticatory and speech functions, were preserved. Conclusion: There was no bone loss around the implants. The association between vertically guided bone regeneration using pericardium resorbable membrane is an alternative technique, and it avoids complications related to non-resorbable membrane exposure. It was shown to be viable after a 3-year follow-up.

Alveolar ridge augmentation with the Bone Into Bone technique: a histological and histomorphometric analysis

Aim Barriers made of cortical bone of heterologous origin are now used as a possible substitute of non-resorbable membranes and bone blocks for the regeneration of bone defects. This report analyzes the efficacy of these barriers, when they are inserted in a surgical slot, vestibular to the defect, using the new Bone into Bone (BiB) technique. Methods A group of 20 patients were treated with the BiB technique, and 32 implants were placed. Bone samples were collected with trephine burs 8 months after surgery and submitted to histological and histomorphometric analysis. The linear horizontal and vertical changes between pre-operative and post-operative radiographs were measured on the CT Scan. Results A mean width gain of 2.36 ± 0. 0.69 mm and a mean height gain of 3.13 ± 0.90 mm was recorded. The biomaterial was almost completely resorbed, and it accounted for 7.39% ± 7.70 of the samples. Conclusion Comparing the current results with those of other investigations, the BiB technique is an efficient alternative to other regenerative approaches, as it provides several advantages, both in terms of reduced morbidity and ease of the procedure. More reports are needed to evaluate the stability of the regenerated bone and to directly compare this technique to other, more commonly used, regenerative procedures.

Comparative In Vivo Analysis of the Integration Behavior and Immune Response of Collagen-Based Dental Barrier Membranes for Guided Bone Regeneration (GBR).

Collagen-based resorbable barrier membranes have been increasingly utilized for Guided Bone Regeneration (GBR), as an alternative to non-resorbable synthetic membranes that require a second surgical intervention for removal. One of the most important characteristics of a resorbable barrier membrane is its mechanical integrity that is required for space maintenance and its tissue integration that plays a crucial role in wound healing and bone augmentation. This study compares a commercially available porcine-derived sugar-crosslinked collagen membrane with two non-crosslinked collagen barrier membranes. The material analysis provides an insight into the influence of manufacturing on the microstructure. In vivo subcutaneous implantation model provides further information on the host tissue reaction of the barrier membranes, as well as their tissue integration patterns that involve cellular infiltration, vascularization, and degradation. The obtained histochemical and immunohistochemical results over three time points (10, 30, and 60 days) showed that the tissue response to the sugar crosslinked collagen membrane involves inflammatory macrophages in a comparable manner to the macrophages observed in the surrounding tissue of the control collagen-based membranes, which were proven as biocompatible. The tissue reactions to the barrier membranes were additionally compared to wounds from a sham operation. Results suggest wound healing properties of all the investigated barrier membranes. However, the sugar-crosslinked membrane lacked in cellular infiltration and transmembraneous vascularization, providing an exclusive barrier function in GBR. Moreover, this membrane maintained a similar swelling ratio over examined timepoints, which suggests a very slow degradation pattern and supports its barrier function. Based on the study results, which showed biocompatibility of the sugar crosslinked membrane and its stability up to 60 days post-implantation, it can be concluded that this membrane may be suitable for application in GBR as a biomaterial with exclusive barrier functionality, similar to non-resorbable options.

Esthetic treatment of anterior implants: A case report

Aesthetic implant treatment in the maxillary anterior area can be challenging, especially in case of insufficient bone volume. In this clinical report, a guided bone regeneration procedure using the combination of xenograft and allograft with non-resorbable membrane was applied in the atrophic edentulous alveolar crest to reconstruct a proper implant bed. Moreover, Prosthetic tissue molding was performed to improve success and optimize aesthetics. This article provides information rele- vant to treatment plans, surgical procedures, and prosthetic management in aesthetically important areas.

Surgical reconstructive treatment for infraosseous peri-implantitis defects with a submerged healing approach: A prospective controlled study.

The aim of this study was to assess the reconstructive potential of a submerged healing approach for the treatment of infraosseous peri-implantitis defects. Patients with a diagnosis of peri-implantitis were recruited. Implant suprastructures were removed before the surgical treatment, which included implant surface and defect detoxification using implantoplasty, air-power driven devices, and locally delivered antibiotics. The augmentation procedure included a composite bone graft and a non-resorbable membrane followed by primary wound coverage and a submerged healing of 8 months, at which point membranes were removed, and peri-implant defect measurements were obtained as the primary outcome. Secondary endpoints included assessment of cone-beam computed tomography (CBCT) and probing depth (PD) reductions. Thirty implants in 22 patients were treated. A significant clinical bone gain of 3.22 ± 0.41mm was observed at 8 months. Radiographic analysis also showed an average gain of 3.47 ± 0.41mm. Three months after installment of new crowns, final PD measures showed a significant reduction compared to initial examinations and a significant reduction in bleeding on probing compared to examinations at the pre-surgical visit. Reconstruction of infraosseous peri-implantitis defects is feasible with thorough detoxification of implant sites, and a submerged regenerative healing approach.

Implants sites with concomitant bone regeneration using a resorbable or non-resorbable membrane result in stable marginal bone levels and similar profilometric outcomes over 5years.

To assess clinical and radiographic outcomes as well as the profilometric contour alterations of peri-implant hard and soft tissues around single implants treated with simultaneous guided bone regeneration (GBR) at 5years. Twenty-seven patients presenting with a single tooth gap in the esthetic zone received a two-piece implant. GBR was randomly performed using a resorbable (RES) or a non-resorbable membrane (N-RES) combined with a bone substitute material. Follow-up examinations were performed at baseline (BL=crown insertion), 1year (FU-1), 3years (FU-3), and at 5years (FU-5) including clinical and radiographic parameters as well as profilometric changes. Statistics were performed by means of parametric and nonparametric tests. At 5years, 20 out of 27 patients (9 RES, 11N-RES) were re-examined. Median values for probing depth changed insignificantly between BL and FU-5 in both groups. The median marginal bone levels were located 0.23mm (0.06; 0.46; RES) and 0.17mm (0.13;0.28; N-RES) below the implant shoulder at FU-5 (changes over time p<.05). The calculated median profilometric change between BL and FU-5 was -0.28mm (-0.53;-0.20; RES; p=.016) and -0.24mm (-0.43;0.08; N-RES; p=.102; intergroup p=.380). The horizontal bone thickness decreased significantly between re-entry and FU-5 for group RES at all measured levels (p<.05) measuring 0.87mm (0.0; 2.05) at the implant shoulder, whereas the decrease for group N-RES was insignificant (p=.031) with 0mm (0; 0.84) at the implant shoulder at 5years. Implants sites with concomitant GBR using a resorbable or non-resorbable membrane revealed stable marginal bone levels and clinical outcomes. Profilometric changes were clinically negligible over 5years. The observed change in hard tissue thickness was partially compensated by an increase in soft tissue thickness.

Clinical evaluation of 3D printed nano-porous hydroxyapatite bone graft for alveolar ridge preservation: A randomized controlled trial

Background/purposeRidge resorption after tooth extraction may result in inadequate bone volume and unfavorable ridge architecture for ideal implant placement. The use of bone substitutes has been advocated to fill extraction sites and to enhance primary implant stability. This study was made to evaluate the clinical efficacy of novel 3D printed nano-porous hydroxyapatite (3DP HA, test group) in comparison to nano-crystalline bone graft (NanoBone®, control group) in alveolar ridge preservation prior to implant placement.Materials and methodsThirty patients were randomized into two groups following tooth extraction. All extracted sockets were filled with 3DP HA or NanoBone® and covered with a non-resorbable membrane. After four months, cone-beam computed tomography (CBCT) and intraoral scanner were used to measure dimensional changes of bone and soft tissue surface. Bone core specimens were harvested for histological analysis during implant osteotomy. Implant stability was assessed using a modified damping capacity analysis.ResultsAt four months postoperatively, dimensional changes in soft tissue surface resorption were less in the test group than in the control group; however, alveolar bone resorption was the same in both groups. Histological analysis revealed new bone formation, residual graft and fibrous connective tissue in both groups. The average primary implant stability (IST) value for both groups was approximately 70. There was no statistically significant difference in all parameters between two groups (p > 0.05).Conclusion3DP HA could potentially be used as an alternative bone graft material for alveolar ridge preservation.

Osseointegration of Dental Implants in Ridges with Insufficient Bones Using Different Membranes for Guided Bone Regeneration

Background:The use of membrane with the guided bone regeneration (GBR) has been a controversial aspect of the implant placement, which helps achieve the primary graft stabilization and inhibit early graft loss.Objectives:The present clinical trial was aimed to determine the results of GBR with nonresorbable (expanded polytetrafluoroethylene [e-PTFE]) and resorbable (collagen) membrane both clinically and radiographically for 2 years with dental implant placement.Materials and Methods:16 subjects having 32 sites for implant placement in a split-mouth pattern were included in the study. The sites for implant was prepared and grafted with the autogenous graft procured from the mandibular ramus area followed by graft coverage with either e-PTFE or collagen membrane. Various radiographic and clinical parameters were assessed for 2 years at an interval of 6 months each. The collected data were recorded for each study subject for all the implant sites and were statistically analyzed.Results:The mean values for periodontal probing depth at 6 months, 12 months, 18 months, and 24 months were 2.25 ± 0.17, 2.67 ± 1.84, 2.64 ± 1.21, and 3.01 ± 0.52, respectively, for the e-PTFE group. For the collagen group, the probing depth mean values at 6 months, 12 months, 18 months, and 24 months were 2.30 ± 0.14, 2.59 ± 1.76, 2.62 ± 1.30, and 2.98 ± 0.81, respectively. The corresponding clinical and radiographic parameters at all time intervals were nonsignificant on the intergroup comparison.Conclusion:Dental implants placed with simultaneous GBR have an acceptable survival rate at the end of 2 years irrespective of the resorbable or non-resorbable membrane used.

A Retrospective Analysis of Treatment Outcomes Following Guided Bone Regeneration at Sites Exhibiting Severe Alveolar Ridge Atrophy.

Severely atrophic alveolar ridges represent a great challenge for implant-prosthetic rehabilitations. The aim of this study was to clinically and histologically evaluate horizontal and vertical bone gain, as well as implant survival/success rate after guided bone regeneration (GBR) for the reconstruction of large bone defects. Fourteen subjects (7 males and 7 females; mean age: 48.9 ± 14.1) were enrolled in the study. They were selected according to specific inclusion criteria and all patients required GBR procedures for placing implants in severe atrophic jaws (bone height ≤6 mm). Guided bone regeneration was performed using dense polytetrafluoroethylene nonresorbable titanium-reinforced membranes associated with particulate heterologous bone grafts. Implant placement was performed 6 months after surgery at the same time as the removal of the membrane. Furthermore, a biopsy sample from the grafted sites was collected to conduct a histological analysis of the regenerated bone. Forty-seven dental implants were placed and followed up after prosthetic loading. Seventeen sites, 8 in the maxilla and 9 in the mandible, were suitable for the GBR procedure. The healing period was uneventful in 13 sites. The average value of vertical bone regeneration was 5.88 ± 1.17 mm. Postloading follow-up ranged from 24 to 59 months. During the follow-up, clinical and radiographic exams showed no significant bone resorption and, in each case, the criteria for implants' survival were respected with no signs of any complications. Histological analysis of the bone biopsy samples revealed residual graft particulate in close contact with newly formed bone. Guided bone regeneration is a reliable technique for reconstruction of severe atrophic ridges. Larger long-term follow-up studies are needed to evaluate the condition of the bone grafted over time and its ability to support functional loading of the implants.

Alveolar Ridge Preservation on Maxillary Molars Using Solvent Dehydrated Bone Allograft and d-PTFE Membrane: A CBCT and Histologic Human Pilot Study.

The purpose of this study was to evaluate vertical and horizontal alveolar resorption after the extraction of eight single maxillary molars using solvent-dehydrated bone allograft (Puros) covered with a nonresorbable membrane for ridge preservation. At implant placement 4 months later, ridge dimensions were measured clinically and radiographically and compared to baseline, and a histologic analysis was performed. The mean buccal height decreased by 1.51 mm at midpoint, 0.88 mm mesially, and 1.16 mm distally. The implants were placed without additional ridge augmentation, and six of eight required an internal sinus elevation. Within the limits of this study, this technique succeeded in preserving the alveolar bone.

DIODE LASER PHOTOCOAGUALTION AS A NOVEL METHOD FOR SOCKET SEALING DURING ALVEOLAR SOCKET PRESERVATION

Introduction: Socket preservation is a procedure after tooth extraction to limit the post-extraction reduction of the ridge volume. Non-contact laser photocoagulation is a simple and atraumatic method used for socket sealing. Objectives: Compare the effect of diode laser photocoagulation to the non-resorbable dense polytetraflouoroethylene (dPTFE) membrane on the bone dimensional changes. Materials and methods: Thirty-six patients (n =18 for each group) with non-restorable maxillary anterior or premolar teeth were included in this study. After extraction, sites were grafted with deproteinized bovine bone xenograft and sealed either with laser photocoagulation or a non-resorbable dPTFE membrane. Measurements of the alveolar bone width were performed on cone beam computed tomographs, taken at the baseline before extraction and after 4 months. Results: Both groups showed a reduction in bone width. At the crest, the mean amount of reduction was 0.69 (0.33) mm and 0.78 (0.15) mm for the laser and membrane groups, respectively. As for the middle third, less amount of reduction was observed by a mean of 0.56 (0.36) mm and 0.58 (0.18) mm for the laser and membrane groups, respectively. The least amount of reduction was in the apical third with a mean of 0.26 (0.36) mm and 0.41 (0.17) mm for the laser and membrane groups, respectively. However, this reduction in bone dimensions was insignificant between both groups. Conclusion: The laser photocoagulation is as effective as the dPTFE membrane in sealing sockets after grafting.

Biocompatibility and Immune Response of a Newly Developed Volume-Stable Magnesium-Based Barrier Membrane in Combination with a PVD Coating for Guided Bone Regeneration (GBR).

To date, there are no bioresorbable alternatives to non-resorbable and volume-stable membranes in the field of dentistry for guided bone or tissue regeneration (GBR/GTR). Even magnesium (Mg) has been shown to constitute a favorable biomaterial for the development of stabilizing structures. However, it has been described that it is necessary to prevent premature degradation to ensure both the functionality and the biocompatibility of such Mg implants. Different coating strategies have already been developed, but most of them did not provide the desired functionality. The present study analyses a new approach based on ion implantation (II) with PVD coating for the passivation of a newly developed Mg membrane for GBR/GTR procedures. To demonstrate comprehensive biocompatibility and successful passivation of the Mg membranes, untreated Mg (MG) and coated Mg (MG-Co) were investigated in vitro and in vivo. Thereby a collagen membrane with an already shown biocompatibility was used as control material. All investigations were performed according to EN ISO 10993 regulations. The in vitro results showed that both the untreated and PVD-coated membranes were not cytocompatible. However, both membrane types fulfilled the requirements for in vivo biocompatibility. Interestingly, the PVD coating did not have an influence on the gas cavity formation compared to the uncoated membrane, but it induced lower numbers of anti-inflammatory macrophages in comparison to the pure Mg membrane and the collagen membrane. In contrast, the pure Mg membrane provoked an immune response that was fully comparable to the collagen membrane. Altogether, this study shows that pure magnesium membranes represent a promising alternative compared to the nonresorbable volume-stable materials for GBR/GTR therapy.

Evaluation of Bone Gain and Complication Rates after Guided Bone Regeneration with Titanium Foils: A Systematic Review.

Guided bone regeneration techniques are increasingly used to enable the subsequent placement of dental implants. This systematic review aims to analyze the success rate of these techniques in terms of bone gain and complications rate using titanium membranes as a barrier element. Electronic and hand searches were conducted in PubMed/Medline, Scielo, Scopus and Cochrane Library databases for case reports, case series, cohort studies and clinical trials in humans published up to and including 19 September 2020. Thirteen articles were included in the qualitative analysis. Bone gain both horizontally and vertically was comparable to that obtained with other types of membranes more commonly used. The postoperative complication rate was higher that of native collagen membranes and non-resorbable titanium-reinforced membranes, and similar that of crosslinked collagen membranes and titanium meshes. The survival rate of the implants was similar to that of implants placed in native bone. Due to the limited scientific literature published on this issue, more randomized clinical trials comparing occlusive titanium barriers and other types of membranes are necessary to reach more valid conclusions.