Evaluation of complication rates and vertical bone gain after guided bone regeneration with non-resorbable membranes versus titanium meshes and resorbable membranes. A randomized clinical trial

Biocompatible Materials for Orbital Wall Reconstruction-An Overview

The reconstruction of an orbit after complex craniofacial fractures can be extremely demanding. For satisfactory functional and aesthetic results, it is necessary to restore the orbital walls and the craniofacial skeleton using various types of materials. The reconstruction materials can be divided into autografts (bone or cartilage tissue) or allografts (metals, ceramics, or plastic materials, and combinations of these materials). Over time, different types of materials have been used, considering characteristics such as their stability, biocompatibility, cost, safety, and intraoperative flexibility. Although the ideal material for orbital reconstruction could not be unanimously identified, much progress has been achieved in recent years. In this article, we summarise the advantages and disadvantages of each category of reconstruction materials. We also provide an update on improvements in material properties through various modern processing techniques. Good results in reconstructive surgery of the orbit require both material and technological innovations.

A collagen membrane for periosteal expansion osteogenesis using a timed-release system in rabbit calvaria

Background

The purpose of this study was to evaluate the effects of resorbable membranes, combined with a shape memory alloy (SMA) mesh device, on bone formation using a timed-release system for periosteal expansion osteogenesis (TIME-PEO).

Materials and methods

Twelve Japanese white rabbits were used in this study. An SMA device was inserted under the forehead periosteum, pushed and bent for attachment to the bone surface, and then fixed using resorbable thread. The rabbits were divided into four groups: C1 (5 weeks postoperatively without membrane), C2 (8 weeks postoperatively without membrane), E1 (5 weeks postoperatively with membrane), and E2 (8 weeks postoperatively with membrane). The rabbits were killed 5 or 8 weeks after the operation and the newly formed bone was assessed histologically and radiographically.

Results

SMA devices, concealed under soft tissue until the time of euthanasia, did not cause active inflammation. The mean activation height, from the original bone surface to the midpoint of the mesh, was 3.1 ± 0.6 mm. Newly formed bone was observed, and most of the subperiosteal space underneath the device was occupied by fibrous tissue. Immature bone was present at the outer surface of the original skull bone in all groups. On histomorphometric analysis, there was no significant difference in the volume of the new bone between C1 and E1 (p = 0.885), and C2 and E2 (p = 0.545).

Conclusions

PEO using an SMA mesh device, which is based on guided bone regeneration (in atrophic alveolar bone), shows promise as an alternative for bone augmentation, irrespective of whether a resorbable membrane is used.

Complications in bone-grafting procedures: Classification and management

Bone-regenerative interventions aiming to restore deficient alveolar ridges, such as the use of block grafts or through the application of guided bone-regeneration principles, have reported positive outcomes in the published scientific literature. These interventions, however, are invasive, and hence, intraoperative and/or postoperative complications may occur. The types of complications and their severity may vary from the exposure of the biomaterial (membrane or graft) to postsurgical infections, neurosensorial disturbances, occurrence of hemorrhage, and pain, etc. The aim of the present narrative review was to search the available scientific evidence concerning the incidence of these complications, their effect on treatment outcomes, their clinical management and, finally, strategies aimed at prevention. Exposure of the barrier membrane or the block graft is the most common complication associated with oral regenerative interventions. To manage these complications, depending on the extent of the exposure and the presence or absence of concomitant infections, therapeutic measures may vary, from the topical application of antiseptics to the removal of the barrier membrane or the block graft. Regardless of their treatment, the occurrence of these complications has been associated with patient selection, with compliant patients (eg, nonsmokers) having a lower reported incidence of complications. Similarly, surgical factors such as correct flap elevation and a tensionless closure are of obvious importance. Finally, to prevent the incidence of complications, it appears prudent to utilize whenever possible less invasive surgical interventions.

3D-based buccal augmentation for ideal prosthetic implant alignment—an optimized method and report on 7 cases with pronounced buccal concavities

Objectives

Screw-retained restoration of implants is advantageous for biological and esthetic reasons. Due to buccal concavities, however, this preferred type of restoration can only be used in about half of the anterior indications. Based on case series, an optimized method for the treatment of such indications is to be described; the clinical reliability is to be ascertained by means of measurements (before and after augmentation) and assigned to the current literature.

Material and methods

A case series of seven cases with buccal concavities of the anterior alveolar ridge were treated with optimized method, which is presented step-by-step until the prosthetic restoration. The depths of the bone concavities were measured and related to the bone gain after augmentation procedure respectively after implantation.

Results

Linear measurements of the buccal concavities showed an average undercut of 4 mm [SD ± 1.13]. After healing period of six months, the buccal concavities could be compensated bony to such an extent that implants could be inserted in correct position and angulation. On average, there was a horizontal bone gain of 3.7 mm [SD ± 0.59]. Even after implantation and another six months of healing, stable bone dimensions could be assumed with an average of 4.3 [SD ± 0.83] mm of bone gain compared to baseline. In six of the seven cases, the favorite screw-retained, one-piece full-ceramic restoration could be fixed on the implants. Due to the implant axis, one case had to be treated with a cemented two-part full-ceramic system.

Conclusions

With the described optimized method the most favorable screw-retained restoration can also be used in situations with unfavorable concavities of buccal bone. Especially for this indication, a special form of the horizontal deficit, the customized bone regeneration with titanium meshes is highly reliable in terms of healing and extent of augmentation. However, long-term results and a study/control group are required to evaluate the effectiveness of the presented protocol.

Clinical relevance.

Since these situations require an augmentation that is up to 5 mm thick and a procedure that is as minimally invasive as possible appears to be necessary in the visible area, an optimized method is described in this publication.

Healing complications and their detrimental effects on bone gain in vertical-guided bone regeneration: A systematic review and meta-analysis

PURPOSE

Guided bone regeneration (GBR) utilizes a barrier membrane to allow osteogenic cells to populate a space by excluding epithelial and connective tissue cells. The purpose of this systematic review was to investigate the ratio of means (RoM) of vertical bone gained (Outcome) in vertical GBR procedures with healing complications (Intervention) and in vertical GBR procedures without healing complications (Comparison) in patients with vertically resorbed edentulous ridges that require dental implant placement (Population). A further aim was to investigate the incidence of complications after vertical GBR, and the influence of the timing of implant placement and regenerative devices on complications.

MATERIALS AND METHODS

MEDLINE (through PubMed), EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched in duplicate up to, and including, November 2020 for randomized and controlled clinical trials and prospective and retrospective case series. Outcomes included patient-level and site-level RoM of vertical bone gain between healing complications and uneventful healing, and incidences of complications that occurred after vertical GBR. Random-effects and fixed-effects meta-analyses were performed where appropriate. This study was registered on PROSPERO (CRD42021226432).

RESULTS

A total of 31 publications were selected for the qualitative and quantitative analyses. The RoM of vertical bone gained was 0.65 [95% CI = 0.47, 0.91] and 0.62 [95% CI = 0.45, 0.85] when membrane exposure without suppuration and abscess formation without membrane exposure occurred respectively, in comparison to uneventful healing. The overall incidence proportion of healing complications occurring at the augmented site at a site- and patient-level was 11.0% [95% CI = 7.0, 15.6] and 10.8% [95% CI = 6.6, 15.7]. At a patient-level, there were no significant differences between a simultaneous or staged approach, or with the regenerative device used. The site-level incidence proportion of membrane exposure without suppuration, membrane exposure with suppuration, and with abscess formation without membrane exposure was 8.7% [95% CI = 4.2, 14.2], 0.7% [95% CI = 0.0, 2.9], and 0.5% [95% CI = 0.0, 1.7], respectively. The site-level weighted mean incidence proportion of neurologic complications occurring at the donor site was 0.8% [95% CI = 0.0, 5.3].

CONCLUSIONS

There is a significant reduction in bone gain when healing complications occur. However, healing complications are relatively uncommon surgical complications after vertical GBR.

Safety and feasibility assessment of biodegradable poly (l-lactic acid/ε-caprolactone) membrane for guided bone regeneration: A case series of first-in-human pilot study

Background/purpose

Guided bone regeneration (GBR) is the most popular technique for alveolar ridge augmentation in implant dentistry, and resorbable cell barrier membrane, made of collagen, is widely used. We tried to develop a new resorbable cell barrier membrane from an animal-free product. This study aimed to investigate the safety and feasibility for clinical application of poly (l-lactic acid/ε-caprolactone) [P (LA/CL)] membrane, a novel biodegradable synthetic material used for GBR.

Materials and methods

Patients who required horizontal bone augmentation (≥3 mm implant exposure) for implant treatment were included in the study. P (LA/CL) membrane was used simultaneously with implant placement to achieve bone augmentation by GBR. The occurrence of adverse events was assessed until the follow-up period of a second surgical procedure. The amount of bone augmentation was assessed by means of cone-beam computed tomography, and implant stability was assessed by measuring the implant stability quotient (ISQ). Student's t-test was used and the level of significance was set at p < 0.05.

Results

This first-in-human study comprised five participants. Adverse events were observed in three of five patients, and a cause-and-effect relationship of the membrane could not be denied in one of them. Good bone formation was observed in the GBR region of all five patients. The ISQ during the second surgical procedure indicated good osseointegration in all the patients.

Conclusion

The application of P (LA/CL) membrane for bone augmentation with GBR made it possible to maintain the augmented bone volume without causing any irreversible adverse events. However, further investigations on humans are required to confirm the safety of this biomaterial.

The Role of Blood Clot in Guided Bone Regeneration: Biological Considerations and Clinical Applications with Titanium Foil

In Guided Bone Regeneration (GBR) materials and techniques are essential to achieve the expected results. Thanks to their properties, blood clots induce bone healing, maturation, differentiation and organization. The preferred material to protect the clot in Guided Bone Regeneration is the titanium foil, as it can be shaped according to the bone defect. Furthermore, its exposition in the oral cavity does not impair the procedure. We report on five clinical cases in order to explain the management of blood clots in combination with titanium foil barriers in different clinical settings. Besides being the best choice to protect the clot, the titanium foil represents an excellent barrier that is useful in GBR due to its biocompatibility, handling, and mechanical strength properties. The clot alone is the best natural scaffold to obtain the ideal bone quality and avoid the persistence of not-resorbed granules of filler materials in the newly regenerated bone. Even though clot contraction still needs to be improved, as it impacts the volume of the regenerated bone, future studies in GBR should be inspired by the clot and its fundamental properties.

Vertical and horizontal ridge augmentation using customized CAD/CAM titanium mesh with versus without resorbable membranes. A randomized clinical trial

Objectives

The aim was to evaluate the role of resorbable membranes applied over customized titanium meshes related to soft tissue healing and bone regeneration after vertical/horizontal bone augmentation.

Materials and Methods

Thirty patients with partial edentulism of the maxilla/mandible, with vertical/horizontal reabsorption of the alveolar bone, and needing implant‐supported restorations, were randomly divided into two groups: Group A was treated using only custom‐made meshes (Mesh‐) and Group B using custom‐made meshes with cross‐linked collagen membranes (Mesh+). Data collection included surgical/technical and healing complications, “pseudo‐periosteum” thickness, bone density, planned bone volume (PBV), regenerated bone volume (RBV), regeneration rate (RR), vertical bone gain (VBG), and implant survival in regenerated areas. Statistical analysis was performed between the two study groups using a significance level of α = .05.

Results

Regarding the healing complications, the noninferiority analysis proved to be inconclusive, despite the better results of group Mesh+ (13%) compared to group Mesh‐ (33%): estimated value −1.13 CI‐95% from −0.44 to 0.17. Superiority approach confirmed the absence of significant differences (p = .39). RBV was 803.27 mm³ and 843.13 mm³, respectively, and higher RR was observed in group Mesh+ (82.3%) compared to Mesh‐ (74.3%), although this value did not reach a statistical significance (p = .44). All 30 patients completed the study, receiving 71 implants; 68 out of them were clinically stable and in function.

Conclusion

The results showed that customized meshes alone do not appear to be inferior to customized meshes covered by cross‐linked collagen membranes in terms of healing complication rates and regeneration rates, although superior results were observed in group Mesh+compared to group Mesh‐ for all variables.

Exposure management of a titanium-reinforced dense polytetrafluoroethylene mesh used in a vertical ridge augmentation: a case report with 1-year follow-up

INTRODUCTION

A new titanium-reinforced dense polytetrafluoroethylene mesh (TR-dPTFEM) has recently been introduced for vertical ridge augmentation (VRA). Since primary closure is required, the literature lacks information on its behavior in case of premature exposure. To the author's knowledge, this is the first report about TR-dPTFEM complication management.

CASE PRESENTATION

A TR-dPTFEM was used for the VRA in the molar region of the upper right maxilla. The defect was filled with a mix of particulate autogenous bone and porcine xenograft in a 1:1 ratio. A collagen membrane covered the hole pattern of the TR-dPTFEM to prevent soft tissue growth within the grafted material during the first weeks. After a 4-month uneventful healing period, a 4-mm exposure occurred without infection. Patient was prescribed 0.2% chlorhexidine mouth rinse three times a day and manual cleansing with gauze soaked in 3% hydrogen peroxide, and was recalled for weekly follow-up. One month later, the clinical situation was unchanged and the site was re-entered. After TR-dPTFEM removal, the regenerated tissue appeared to be covered with a thin layer of connective tissue. The favorable bone quality made it possible to obtain the primary stability of two implants. At implant uncovering, a gingival graft augmented the keratinized mucosa width. Two screw-retained crowns were delivered 4 months after implant insertion and the 1-year follow-up showed perfectly maintained hard and soft tissues.

CONCLUSION

A late TR-dPTFEM exposure, managed under strict hygiene control, did not affect this VRA. The augmented bone remained stable 1 year after prosthetic loading.

KEY POINTS

Why is this case new information? A novel titanium reinforced PTFE mesh has been recently introduced for vertical ridge augmentation. This case report adds new information to the literature about the management and clinical outcome in a case of exposure. What are the keys to successful management of this case? Weekly check-up of the patient by the clinician Patient's ability to keep the wound clean and disinfected What are the primary limitations to success in this case? Impossibility of being able to check the patient at least once a week Acute infection.

In Vivo Biological Evaluation of Biodegradable Nanofibrous Membranes Incorporated with Antibiofilm Compounds

Guided bone regeneration involves excluding non-osteogenic cells from the surrounding soft tissues and allowing osteogenic cells originating from native bone to inhabit the defect. The aim of this work was to fabricate, analyze antibiofilm activity and evaluate in vivo biological response of poly (lactic-co-glycolic acid) (PLGA) electrospun membranes incorporated with tea tree oil and furan-2(5H)-one. Samples were exposed to Streptococcus mutans culture and after 48 h incubation, biofilm was evaluated by colony forming units (CFU/mL) followed by scanning electron microscopy. Additionally, seventy-five Balb-C mice were divided into five experimental groups for subcutaneous implantation: tea tree oil loaded PLGA electrospun fiber membrane, furanone loaded PLGA electrospun fiber membrane, neat PLGA electrospun fiber membrane, a commercially available PLGA membrane –Pratix^® and Sham (no-membrane implantation). Post implantation period of each experimental group (1, 3 and 9 weeks), samples were collected and processed for by histological descriptive and semiquantitative evaluation. Results showed a significant reduction of bacterial attachment on tea tree oil and furan-2(5H)-one incorporated membranes. Macrophage counts were significant found in all the materials implanted, although giant cells were predominantly associated with electrospun fiber membranes. The incorporation of antibiofilm compounds in nanofibers membranes did not incite inflammatory response significantly different in comparison with pure PLGA electrospun membranes, indicating its potential for development of novel functionalized membranes targeting the inhibition of bacterial biofilms on membrane-grafting materials.

Addition of autogenous bone chips to deproteinized bovine bone mineral does not have additional benefit in lateral ridge augmentation-A preclinical in vivo experimental study

OBJECTIVE

To compare the outcome after extensive lateral guided bone regeneration using deproteinized bovine bone mineral (DBBM) with or without autogenous bone chips in a canine model of chronic horizontal alveolar ridge defect.

MATERIALS AND METHODS

The second, third and fourth lower premolars of both sides were extracted, and the buccal bone walls were completely removed in five beagle dogs. After 4 weeks, DBBM particles mixed with autogenous bone chips at a ratio of 1:1 were grafted at one side (DBBM/Auto group), while DBBM particles alone were grafted at the contralateral side (DBBM group). The graft materials on both sides were covered by a resorbable collagen membrane and fixation pins. Microcomputed tomographic volume and histomorphometric analyses were performed at 16 weeks post-surgery.

RESULTS

The ridges of both groups were recovered horizontally, but new bone formation beyond the original ridge contour at the defect site was not found. The DBBM group exhibited a larger total radiographic augmented volume and new bone volume compared with the DBBM/Auto group, but the differences were minimal (p > .05). Histologically, the regenerated area and new bone area were also slightly larger without any statistical significance in the DBBM group than in the DBBM/Auto group (p > .05).

CONCLUSION

The addition of autogenous bone chips to DBBM for lateral ridge augmentation may confer no advantage over grafting DBBM alone with respect to both space maintenance and de novo bone formation in dogs.

Guided bone regeneration simultaneous with implant placement using bovine-derived xenograft with and without liquid platelet-rich fibrin: a randomized controlled clinical trial

OBJECTIVE

To assess augmentation success after guided bone regeneration (GBR) carried out simultaneously with implant placement using bovine-derived xenograft alone and in combination with liquid platelet-rich fibrin (liquid-PRF).

METHODS

This randomized controlled clinical trial was conducted on patients with horizontal bone deficiency in the posterior regions of the mandible. After implant placement, GBR procedures were randomly performed using liquid-PRF-enriched bovine-derived xenograft (for the test group) and with bovine-derived xenograft alone (for the control group). To assess the change in augmentation thickness, the primary outcome of the study, cone beam computed tomography was carried out at the implant sites on completion and 6 months after surgery. The secondary outcomes were marginal bone level and implant survival rate at prosthetic delivery and at 6 months, 1 year, and 2 years follow-up after loading. The significance level was set at p<0.05 for all analysis.

RESULTS

Twenty patients with 50 implants were analyzed for the test group and 20 patients with 48 implants for the control group. At 6 months postoperatively, the mean values of augmentation thickness were 1.63 ± 0.21 mm, 2.59 ± 0.34 mm, and 3.11 ± 0.36 mm for the test group and 1.34 ± 0.14 mm, 2.49 ± 0.24 mm, and 2.97 ± 0.24 mm for the control group at 2 mm, 4 mm, and 6 mm below to the implant shoulder (p < 0.001, p = 0.007, and p = 0.036, respectively). The mean marginal bone loss was found to be less than 1 mm for both study groups during the 2 years of follow-up after prosthetic loading. Implant survival rate was 100% for both study groups.

CONCLUSION

Bovine-derived xenograft alone and in combination with liquid-PRF are both successful in achieving bone augmentation around the implants and produce a small change in marginal bone level and a high implant survival rate after loading.

CLINICAL RELEVANCE

There is a lack of evidence in the literature regarding the augmentation success of liquid-PRF used in combination with bone graft substitutes. This study indicates that liquid-PRF could be used as a supportive material with bovine-derived xenograft in GBR procedures carried out simultaneously with implant placement.

Vertical bone augmentation utilizing a titanium-reinforced PTFE mesh: A multi-variate analysis of influencing factors

OBJECTIVE

To clinically evaluate the use of a titanium-reinforced PTFE mesh for vertical bone augmentation (VBA) of deficient alveolar ridges.

MATERIALS AND METHODS

This case series documented consecutive patients treated for VBA with a newly developed PTFE mesh. VBA was performed in anterior and posterior, maxillary and mandibular arches using anorganic bovine bone combined with autogenous graft in a 1:1 ratio. Healing time from initial surgery to re-opening was recorded. Baseline vertical deficiency, absolute bone gain (gross height gained), and relative gain (percentage of defect fill with respect to the baseline deficiency) were registered.

RESULTS

Fifty-seven patients (65 defects) were included in the analysis. The mean baseline vertical deficiency was 5.5 ± 2.6 mm. The mean absolute bone gain was 5.2 ± 2.4 mm. A relative gain of 96.5 ± 13.9% was achieved. Overall, 89.2% of cases showed complete regeneration, which occurred in all sites with baseline deficiencies of <5 mm, in 95.6% of sites with 5-8 mm deficiencies, and in 89.4% of sites with >8 mm deficiencies. Each 1-mm addition to the baseline height deficiency increased the likelihood of incomplete bone regeneration by 2.5 times. Defect location had a statistically significant but a limited clinical impact on the bone height gained (<0.5 mm). Complications were observed in three cases (3%).

CONCLUSIONS

Vertical bone augmentation with titanium-reinforced PTFE mesh and a mixture of autologous bone and xenograft is a safe and predictable procedure. The extent of the baseline vertical deficiency influences the percentage of bone gained.

The Role of Custom-made Subperiosteal Implants for Rehabilitation of Atrophic Jaws - A Case Report

Rehabilitation of atrophic jaws with conventional endosseous implant-supported overdentures and immediate loading protocols still presents a challenge nowadays. Custom-made implants with immediate loading overdenture are emerging as a solution for atrophic jaws rehabilitation. The authors describe the case of a 44-year-old male with a history of congenital dental agenesis. A previous oral rehabilitation with an all-on-6 type, implant-fixed mandibular overdenture, had failed due to peri-implantitis. The patient was successfully treated with bimaxillary custom-made subperiosteal implants with an innovative design, combining subperiosteal and endosseous support. The authors consider custom-made subperiosteal implants, in selected patients, present several advantages over classic bone-grafting plus endosseous implant-placement techniques such as (1) possibility of a single-stage procedure with immediate loading in atrophic jaws; (2) possible primary option to approach atrophic jaws as a simpler and less time-consuming technique; and (3) a valid rescue option for failed endosseous implants. More long-term studies with large samples of patients will be necessary to confirm previous assumptions.

Titanium Meshes in Guided Bone Regeneration: A Systematic Review

The presence of satisfactory bone volume is fundamental for the achievement of osseointegration. This systematic review aims to analyse the use of titanium meshes in guided bone regeneration in terms of bone gain, survival and success rates of implants, and percentages of exposure. An electronic search was conducted Articles were selected from databases in MEDLINE (PubMed), SCOPUS, Scielo, and Cochrane Library databases to identify studies in which bone regeneration was performed through particulate bone and the use of titanium meshes. Twenty-one studies were included in the review. In total, 382 patients, 416 titanium meshes, and 709 implants were evaluated. The average bone gain was 4.3 mm in horizontal width and 4.11 mm in vertical height. The mesh exposure was highly prevalent (28%). The survival rate of 145 simultaneous implants was 99.5%; the survival rate of 507 delayed implants was 99%. The success rate of 105 simultaneous implants was 97%; the success rate of 285 delayed implants was 95.1%. The clinical studies currently available in the literature have shown the predictability of this technique. It has a high risk of soft tissue dehiscence and membrane exposure although the optimal management of membrane exposition permits obtaining a sufficient bone regeneration volume and prevents compromising the final treatment outcome.

Customized CAD/CAM titanium meshes for the guided bone regeneration of severe alveolar ridge defects: Preliminary results of a retrospective clinical study in humans

OBJECTIVES

To present the results of guided bone regeneration (GBR) of atrophic edentulous ridges with customized CAD/CAM titanium meshes.

MATERIAL AND METHODS

Forty-one patients, presenting with 53 atrophic sites, were enrolled between 2018 and 2019. GBR was obtained with titanium meshes filled with autogenous bone chips and bovine bone mineral (BBM). After a mean of 7 months (range: 5-12 months), meshes were removed and 106 implants placed. After a mean of 3.5 months (range: 2-5 months), implants were uncovered and prosthetic restorations started. The outcomes were vertical and horizontal bone augmentation changes, biological complications and implant survival.

RESULTS

Out of 53 sites, 11 underwent mesh exposure: eight of them were followed by uneventful integration of the graft, while three by partial bone loss. The mean vertical and horizontal bone gain after reconstruction was 4.78 ± 1.88 mm (range 1.00-8.90 mm) and 6.35 ± 2.10 mm (range 2.14-11.48 mm), respectively. At the time of implant placement, mean changes of initial bone gain were -0.39 ± 0.64 mm (range -3.1 to + 0.80 mm) and -0.49 ± 0.83 mm (range -3.7 to +0.4 mm), in the vertical and horizontal dimensions, respectively. Reduction of bone volume was significantly higher (p < .001 for both dimensions) in the exposed sites. The mean follow-up of implants after loading was 10.6 ± 6.5 months (range: 2-26 months). The survival rate of implants was 100%.

CONCLUSION

Customized titanium meshes can represent a reliable tool for GBR of severely atrophic sites, with simplification of the surgical phases.

In vitro degradation, biocompatibility and antibacterial properties of pure zinc: assessing the potential of Zn as a guided bone regeneration membrane

Membrane exposure is a common complication after the guided bone regeneration (GBR) procedure and has a detrimental influence on the bone regeneration outcomes, while the commercially available GBR membranes show limited exposure tolerance. Recently, zinc (Zn) has been suggested as a promising material to be used as a barrier membrane in GBR therapy for bone augmentation. In this study, the degradation behavior in artificial saliva solution, cytotoxicity and antibacterial activity of pure Zn were investigated to explore its degradation and associated biocompatibility in the case of premature membrane exposure. The results indicated that the degradation rate of Zn in artificial saliva solution was about 31.42 μm year-1 after 28 days of immersion. The corrosion products on the Zn surface were mainly composed of Zn3(PO4)2, Ca3(PO4)2, CaHPO4, Zn5(CO3)2(OH)6 and ZnO. Besides, Zn presented an acceptable in vitro HGF cytocompatibility and a high antibacterial activity against Porphyromonas gingivalis. The preliminary results demonstrate that pure Zn exhibits appropriate degradation behavior, adequate cell compatibility and favorable antibacterial properties in the oral environment and is thus believed to sustain profitable function when membrane exposure occurs. The results provided new insights for understanding the exposure tolerance of Zn based membranes and are beneficial to their clinical applications.

Mineralized Plasmatic Matrix for Horizontal Ridge Augmentation in Anterior Maxilla with and without a Covering Collagen Membrane

Background:

Mineralized Plasmatic Matrix [MPM] is a unique form of platelet rich fibrin that contains mineralized bone graft particles within a fibrin network.

Aim:

This study was conducted to evaluate horizontal ridge augmentation using MPM with and without a coverage membrane.

Materials and Methods:

Sixteen edentulous spaces were randomly divided into 2 equal groups. MPM was used for horizontal ridge augmentation with and without a covering collagen membrane (group 1 and 2, respectively). Cone Beam CT images were obtained preoperatively as well as 1 week and 4 months postoperatively to evaluate alveolar ridge and the resorption of the grafting material at 3 predetermined points along with the site where the future dental implant will be placed.

Student’s t-test (Unpaired) was used for comparing two different groups with quantitative parametric data and student’s t-test (Paired) was used for comparing two related groups with quantitative parametric data while repeated measures ANOVA (Analysis of variance) followed by post-hoc Bonferroni was used for comparing more than two related groups with quantitative parametric data.

Student’s t-test (Unpaired) was used for comparing two different groups with quantitative parametric data and student’s t-test (Paired) was used for comparing two related groups with quantitative parametric data while repeated measures ANOVA (Analysis of variance) followed by post-hoc Bonferroni was used for comparing more than two related groups with quantitative parametric data.

Results:

There was no statistically significant difference between the gained bone width in both groups. More but not statistically significant resorption was recorded in group 2.

Conclusion:

MPM can be successfully used for horizontal ridge augmentation without a barrier membrane.

Titanium mesh for bone augmentation in oral implantology: current application and progress

Guided bone regeneration (GBR) is an effective and simple method for bone augmentation, which is often used to reconstruct the alveolar ridge when the bone defect occurs in the implant area. Titanium mesh has expanded the indications of GBR technology due to its excellent mechanical properties and biocompatibility, so that the GBR technology can be used to repair alveolar ridges with larger bone defects, and can obtain excellent and stable bone augmentation results. Currently, GBR with titanium mesh has various clinical applications, including different clinical procedures. Bone graft materials, titanium mesh covering methods, and titanium mesh fixing methods are also optional. Moreover, the research of GBR with titanium mesh has led to multifarious progresses in digitalization and material modification. This article reviews the properties of titanium mesh and the difference of titanium mesh with other barrier membranes; the current clinical application of titanium mesh in bone augmentation; common complications and management and prevention methods in the application of titanium mesh; and research progress of titanium mesh in digitization and material modification. Hoping to provide a reference for further improvement of titanium mesh in clinical application and related research of titanium mesh.

Internal oblique line implants in severe mandibular atrophies

Background

Maxillary atrophy may be related to mechanical, inflammatory or systemic factors, being a consequence of a reduction in the amount and quality of available bone. Several surgical techniques have been developed for the restoration of bone volume needed for placing dental implants; guided bone regeneration or three-dimensional reconstructions with autologous bone, inter alia, are techniques described in the literature which demonstrate this, all of which preceded by a proper prosthetic surgical assessment. Even when the majority of authors recommend the use of these techniques prior to placing implants, it has been shown that implants with a smaller diameter and length may be placed in severely atrophied jaws without the need for performing any surgery, offering excellent results.

Material and Methods

Twenty-four (24) implants were placed in six patients with severe mandibular atrophy. The implants were placed in the anterior sector and on an internal oblique line. Patients were rehabilitated with a total implant-supported prosthesis, with monitoring over a 10-year period.

Results

After a 12-month monitoring period, all the patients presented successful rehabilitation. Marginal bone loss in general (n=24 implants) was +0.11 mm ± 0.53. In the implants in zones 1 and 4 (posterior) it was +0.06 mm ± 0.48 and in implants in zones 2 and 3 (anterior), +0.14 mm ± 0.57.

Conclusions

Implants can be placed in the anterior zone and on an internal oblique line in patients with severe mandibular atrophy, using a diameter and length adapted to bone availability, for later prosthetic rehabilitation, offering satisfactory results since phonetic and masticatory function can be restored, as well as facial and buccal aesthetics, in a single surgical operation, with minimum morbidity. Key words:Severe atrophy, implants, bone grafts, ridge atrophy, internal oblique line.

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.

Vertical Bone Gain after Sinus Lift Procedures with Beta-Tricalcium Phosphate and Simultaneous Implant Placement-A Cross-Sectional Study

OBJECTIVES

The objective of this cross-sectional study was to evaluate the vertical bone gain achieved after the sinus lift procedure with beta-tricalcium phosphate (β-TCP) used as a bone substitute and simultaneous implant placement.

METHODS

One hundred and twenty-eight sinus lift procedures (utilizing a synthetic ceramic containing 99.9% tricalcium phosphate as a bone substitute) and simultaneous implant placements were performed on 119 patients. The lateral window approach surgical protocol for maxillary sinus lift was performed on the patients. The implants were evaluated using cone-beam computed tomography (CBCT) at 6 months following placement. The vertical bone gain was considered a primary variable, while implant length, diameter, and location were considered secondary variables.

RESULTS

The ANOVA results showed no statistical difference in vertical bone gain with implant parameters like implant length, width, and position. Pearsons correlation revealed a statistically significant positive correlation with vertical bone gain and implant length and diameter. A further multivariate linear regression analysis was performed and it observed statistically significant associations between the variables in the study after adjusting for confounding factors.

CONCLUSIONS

This study concluded that there was vertical bone gain with the usage of β-TCP in maxillary sinus lift surgical procedure with immediate implant placement and that implant variables like length and diameter had a significant influence on the average bone gain values. The implant position did not have a statistically significant influence but there was considerable variation in the bone gain between first, second premolar, and molar regions.

Guided bone regeneration

Guided bone regeneration (GBR) is a surgical procedure that utilizes bone grafts with barrier membranes to reconstruct small defects around dental implants. This procedure is commonly deployed on dehiscence or fenestration defects ≥2 mm, and mixing with autogenous bone is recommended on larger defects. Tension-free primary closure is a critical factor to prevent wound dehiscence, which is critical cause of GBR failure. A barrier membrane should be rigidly fixed without mobility. If the barrier is exposed, closed monitoring should be utilized to prevent secondary infection.

Vertical ridge augmentation (VRA) with Ti-reinforced d-PTFE membranes or Ti meshes and collagen membranes: 1-year results of a randomized clinical trial

OBJECTIVES

The aim of this study was to evaluate hard and soft tissues around implants placed in posterior mandible 1 year after vertical ridge augmentation (VRA).

MATERIALS AND METHODS

40 patients with vertical defects were enrolled and treated according to the study protocol. Patients were randomly divided into two study groups: reinforced PTFE membranes (group A) and titanium meshes plus collagen membranes (group B). All patients received simultaneous implants which were evaluated after prosthetic restoration at baseline and after 1 year, using the following parameters: peri-implant bone levels (PBLs), interproximal bone peaks (IBPs), pocket probing depth (PPD), bleeding on probing (BoP), plaque index (mPI), gingival index (mGI), keratinized tissue thickness/width (tKT and wKT), and fornix depth (FD). Statistical analysis was performed to investigate any statistically significant differences and/or correlations (p = .05).

RESULTS

30 patients were completely followed up according to the study protocol. After 1 year, implants showed a change in PBL from 0.12 to 0.76 mm, with marginal bone loss of 0.67 and 0.61 mm for group A and group B, respectively, without significant differences (p > .9337). The estimated difference between treatments for the change from baseline in PBL was -0.05 (95% CI -0.27 to 0.16). Statistical analysis revealed strong correlations between PBL and IBP (p < .0001). However, no significant differences were observed for PPD, mPI, mGI, tKT, wKT, and FD (p > .05).

CONCLUSION

The results indicate that GBR treatment with titanium meshes plus collagen membranes (Group B) compared to reinforced PTFE membranes does not appear to be inferior or superior in terms of PBL change. In both groups, hard and soft tissues were stable after 1 year of follow-up, with a peri-implant bone loss less than 1.0 mm in the first year (study registered at ClinicalTrials.gov NCT04332679).

Multilayered Connective Tissue Grafting Technique to Improve Aesthetics after Failed GBR: A Clinical Case Report of 16 Months Follow-Up

Objective

This case report describes soft-tissue management after a failed GBR procedure to enhance the soft-tissue quality, quantity, and aesthetic outcomes. Case Presentation. A 38-year-old patient visited the Dental Clinic of the Ospedale Maggiore Policlinico, University of Milan, Milan, Italy, for a chief complaint of unsatisfactory aesthetics of the anterior maxillary area. Dental history disclosed failed preimplant vertical bone augmentation with GBR procedure in the area of the left maxillary central incisor resulting in a severe gingival recession of adjacent teeth and compromised soft-tissue quantity and quality and severe ridge atrophy (class III). Multilayered connective tissue grafting technique, in a two-step mucogingival surgery, was used to cover the gingival recessions, reach even gingival margin, and reconstruct the defect. Frenectomy was done after the second mucogingival surgery to relieve the muscle attachment. A definitive cantilever bridge was placed to restore the left and right maxillary central incisors, and a satisfactory aesthetic outcome was reached.

Conclusions

Multilayered connective tissue grafting technique might be successful in correcting soft-tissue quantity and quality in class III ridge defects.

Clinical and volumetric outcomes after vertical ridge augmentation using computer-aided-design/computer-aided manufacturing (CAD/CAM) customized titanium meshes: a pilot study

Background

One of the most recent innovations in bone augmentation surgery is represented by computer-aided-design/computer-aided-manufacturing (CAD/CAM) customized titanium meshes, which can be used to restore vertical bone defects before implant-prosthetic rehabilitations. The aim of this study was to evaluate the effectiveness/reliability of this technique in a consecutive series of cases.

Methods

Ten patients in need of bone augmentation before implant therapy were treated using CAD/CAM customized titanium meshes. A digital workflow was adopted to design virtual meshes on 3D bone models. Then, Direct Metal Laser Sintering (DMLS) technology was used to produce the titanium meshes, and vertical ridge augmentation was performed according to an established surgical protocol. Surgical complications, healing complications, vertical bone gain (VBG), planned bone volume (PBV), lacking bone volume (LBV), regenerated bone volume (RBV), average regeneration rate (RR) and implant success rate were evaluated.

Results

All augmented sites were successfully restored with definitive implant-supported fixed partial dentures. Measurements showed an average VBG of 4.5 ± 1.8 mm at surgical re-entry. Surgical and healing complications occurred in 30% and 10% of cases, respectively. Mean values of PBV, LBV, and RBV were 984, 92, and 892 mm³, respectively. The average RR achieved was 89%. All 26 implants were successfully in function after 1 year of follow-up.

Conclusions

The results of this study suggest that the bone augmentation by means of DMLS custom-made titanium meshes can be considered a reliable and effective technique in restoring vertical bone defects.

The effect of macrophages on an atmospheric pressure plasma-treated titanium membrane with bone marrow stem cells in a model of guided bone regeneration

Guided bone regeneration (GBR) is an established treatment. However, the mechanisms of GBR are not fully understood. Recently, a GBR membrane was identified that acts as a passive barrier to regenerate bone via activation and migration of macrophages (Mps) and bone marrow stem cells (BMSCs). Atmospheric pressure plasma treatment of the titanium membrane (APP-Ti) activated macrophages. The purpose of this study was to analyze whether macrophages attached to an APP-Ti membrane affected differentiation of BMSCs in a GBR model. Human THP-1 macrophages (hMps) were cultured on non-treated Ti (N-Ti) and APP-Ti membrane. Macrophage polarization was analyzed by RT-PCR and immunocytochemistry. Secreted proteins from hMps on N-Ti and APP-Ti were detected by LC/MS/MS. hBMSCs were co-cultured with hMps on N-Ti or APP-Ti and analyzed by osteogenic differentiation, Alizarin red S staining, and alkaline phosphatase (ALP) activity. N-Ti and APP-Ti membrane were also implanted into bone defects of rat calvaria. hMps on APP-Ti were polarized M2-like macrophages. hMps on N-Ti secreted plasminogen activator inhibitor-1 and syndecan-2, but hMps on APP-Ti did not. hBMSCs co-cultured with hMps on APP-Ti increased cell migration and gene expression of osteogenic markers, but suppressed mineralization, while ALP activity was similar to that of hMps on N-Ti in vitro. The volume of newly formed bone was not significantly different between N-Ti and APP-Ti membrane in vivo. M2 polarized hMps on APP-Ti suppressed osteogenic induction of hBMSCs in vitro. The indirect role of hMps on APP-Ti in newly formed bone was limited.

A pure zinc membrane with degradability and osteogenesis promotion for guided bone regeneration: In vitro and in vivo studies

Selection of an appropriate membrane material for guided bone regeneration (GBR) is still ongoing among resorbable and nonresorbable membranes with different characteristics. The major problem with nonresorbable membranes is the inevitable secondary surgery, while resorbable polymer membranes have limitations in providing sufficient mechanical support during the bone repair period due to premature loss of mechanical strength. Pure magnesium foil has been evaluated to explore its feasibility as a resorbable GBR membrane. It exhibited better mechanical properties, whereas poor formability and fast degradation rate were noted. In light of this, pure zinc membrane was developed as a pilot research in this paper. We designed three types of pure zinc membranes: pure Zn without pores, pure Zn with 300 µm diameter and 1000 µm diameter pores, and pure titanium without pores as a control. The mechanical property, in vitro immersion tests, and MC3T3-E1 cell viability assays were tested. Moreover, in vivo behaviors of three type zinc membranes were evaluated by using a rat calvarial critical-sized bone defect model. The experimental results indicated that pure Zn membrane with 300 µm pores showed the most favorable osteogenic capability, comparable to that of titanium membrane without pores. Therefore, considering appropriate degradation rate, adequate mechanical maintenance, and profitable osteogenic capacity, metallic pure zinc is believed to be a promising candidate for barrier membranes in GBR therapy for bone regeneration, and its mechanical property can be enhanced with further alloying. STATEMENT OF SIGNIFICANCE: Metallic element zinc plays a pivotal role in the growth and mineralization of bone tissues. As a pilot research, three type of guided bone regeneration (GBR) membranes were developed in the present work: pure Zn without pores, pure Zn with 300 µm-diameter and 1000 µm-diameter pores respectively. The mechanical property, in vitro immersion tests and MC3T3-E1 cell viability assays were tested, with pure titanium without pores as a control, thereafter the in vivo performance were evaluated by using a rat calvarial critical-sized bone defect model. It indicated that pure Zn membrane with 300 µm pores showed the most favorable osteogenic capability, comparable to that of titanium membrane control, and is believed to be a promising material candidate as barrier membrane in GBR therapy for bone regeneration.

Characterization of a Bioresorbable Magnesium-Reinforced PLA-Integrated GTR/GBR Membrane as Dental Applications

Inferior mechanical properties have always been a limitation of the bioresorbable membranes in GBR/GTR. This study is aimed at fabricating a bioresorbable magnesium-reinforced polylactic acid- (PLA-) integrated membrane and investigating its mechanical properties, degradation rate, and biocompatibility. The uncoated and fluoride-coated magnesium alloys, AZ91, were made into strips. Then, magnesium-reinforced PLA-integrated membrane was made through integration. PLA strips were used in the control group instead of magnesium strips. Specimens were cut into rectangular shape and immersed in Hank's Balanced Salt Solution (HBSS) at 37°C for 4, 8, and 12 d. The weight loss of the AZ91 strips was measured. Three-point bending tests were conducted before and after the immersion to determine the maximum load on specimens. Potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) were conducted on coated and uncoated AZ91 plates to examine corrosion resistance. Murine fibroblast and osteoblast cells were cultured on circular specimens and titanium disks for 1, 3, and 5 d. Thereafter, WST test was performed to examine cell proliferation. As a result, the coated and uncoated groups showed higher maximum loads than the control group at all time points. The weight loss of AZ91 strips used in the coated group was lower than that in the uncoated group. PDP, EIS, SEM, and EDS showed that the coated AZ91 had a better corrosion resistance than the uncoated AZ91. The cell proliferation test showed that the addition of AZ91 did not have an adverse effect on osteoblast cells. Conclusively, the magnesium-reinforced PLA-integrated membrane has excellent load capacity, corrosion resistance, cell affinity, and proper degradation rate. Moreover, it has great potential as a bioresorbable membrane in the GBR/GTR application.

A clinical and radiographical comparison of buccolingual crestal bone changes after immediate and delayed implant placement

Aim

The study aims to clinically and radiographically compare the bucco-lingual crestal bone changes after immediate and delayed placement of implants.

Methods

Two groups that consisted of fifty implants were considered for this study. In group A the implants were placed immediately post extraction, whereas, in group B implants placement were delayed by four to six weeks. All the implants were submerged within the alveoli confines. Bone grafts were only placed if the jumping distance was more than 1.5 mm. Barrier membrane was not placed in any of the cases. Bucco-lingual width was measured at the time of implant placement and during abutment placement after four to six weeks. Primary flap closure was ensured in all the cases.

Results

Thirty-one implants were placed in the mandible and nineteen were placed in the maxilla. All the implants achieved osseointegration. Immediate implant group showed a mean width of 8.80 mm (SD2.280) at the time of implant placement whereas, 7.60 mm (SD 1.871) after six months. Delayed implant group showed a mean width of 8.40 mm (SD1.673) at the time of implant placement, and 7.40 mm (SD 1.658) after six months. Intragroup showed statistically significant data (P<0.05). When the intergroup comparison of group 1 and group 2 was made at implant placement day and abutment placement day, it was found to be statistically non-significant.

Conclusion

This study suggests that circumferential defect heals on itself without any guided bone regeneration in both the groups. The data suggests that the healing in both the group were equally good. The equally good results suggest placing the implant immediately post extraction. This saves the cost, time and most importantly the need for an extra surgery.

Biomaterial-based bone regeneration and soft tissue management of the individualized 3D-titanium mesh: An alternative concept to autologous transplantation and flap mobilization

Three-dimensional augmentation in severely atrophic bone and after cancer resection is a challenging clinical indication that is mostly solved using autologous bone transplantation. The development of the digital technique along with the additive manufacturing and three-dimensional (3D) printing opened new avenues for reconstructive oral and maxillofacial surgery. Therefore, patient-specific titanium mesh is a novel means of stabilizing the augmentation region using particulate bone substitute materials (BSMs) combined with autologous bone as a minimally invasive concept. However, dehiscence is a frequently reported complication in this field. Therefore, the aim of the present case series was to introduce a biomaterial-based regenerative concept in terms of exposed open healing to overcome the dehiscence related to 3D-titanium meshes. Additionally, this case series presents a novel protocol using a combination of xenogeneic BSMs with an autologous blood concentrate system (platelet-rich fibrin [PRF]) and collagen matrices without any autologous transplantation. Seven patients with alveolar ridge atrophy with different etiologies (cancer resection, severe atrophy after tooth loss, aplasia, trauma, implant infections) were treated using the open-healing concept. Therefore, after 3D augmentation using the described biomaterials, the flap margins were approximated, and the gap between the flap margins was bridged using a collagen matrix loaded with liquid PRF that was then covered by either a PTFE-based membrane or sterile latex. No periosteum splitting was performed at any time point. After a healing period of 4-8 months, all patients received dental implants as virtually planned. Bone biopsies were performed during dental insertion for histological evaluation. The augmentation area displayed a vital and well-vascularized newly formed bone that incorporated the BSM granules to build a hybrid bone. Additionally, open healing resulted in newly formed soft tissue without any signs of scar formation or fibrosis. The regenerated soft tissue was used to build a new flap during implant insertion and showed good functional and aesthetic results after implant insertion. The open-healing concept of the regeneration of the soft tissue along with bone tissue to regenerate a harmonic implantation bed is a minimally invasive intervention without periosteum splitting or large flap mobilization. However, further controlled clinical studies are needed to evaluate this concept in a larger patient cohort to outline the potential clinical benefit.

Tailored Biomaterials for Therapeutic Strategies Applied in Periodontal Tissue Engineering

Several therapeutic strategies are currently in development for severe periodontitis and other associated chronic inflammatory diseases. Guided tissue regeneration of the periodontium is based on surgical implantation of natural or synthetic polymers conditioned as membranes, injectable biomaterials (hydrogels), or three-dimensional (3D) matrices. Combinations of biomaterials with bioactive factors represent the next generation of regenerative strategy. Cell delivery strategy based on scaffold-cell constructs showed potential in periodontitis treatment. Bioengineering of periodontal tissues using cell sheets and genetically modified stem cells is currently proposed to complete existing (pre)clinical procedures for periodontal regeneration. 3D structures can be built using computer-assisted manufacturing technologies to improve the implant architecture effect on new tissue formation. The aim of this review was to summarize the advantages and drawbacks of biomimetic composite matrices used as biomaterials for periodontal tissue engineering. Their conditioning as two-dimensional or 3D scaffolds using conventional or emerging technologies was also discussed. Further biotechnologies are required for developing novel products tailored to stimulate periodontal regeneration. Additional preclinical studies will be useful to closely investigate the mechanisms and identify specific markers involved in cell-implant interactions, envisaging further clinical tests. Future therapeutic protocols will be developed based on these novel procedures and techniques.

Resorbable Versus Nonresorbable Membranes: When and Why?

Guided bone-regeneration techniques use either resorbable or nonresorbable membrane. Ideal membrane material should be biocompatible with tissue integration, be able to create and maintain space, be occlusive with selective permeability, and have good handling properties. Commercially available nonresorbable membranes are Gor-tex (e-PTFE), Cytoplast (d-PTFE), and titanium mesh. Resorbable membranes are available as natural and synthetic. Clinical trials, a systematic review and meta-analysis have shown no statistically significant difference in most clinical indications between both types of membrane. The choice of membrane varies according to the choice of grafting materials and nature of defect.

Evaluation of complication rates and vertical bone gain after guided bone regeneration with non-resorbable membranes versus titanium meshes and resorbable membranes. A randomized clinical trial

Background

The partial edentulous posterior mandible is often a challenge area that requires a bone reconstructive surgery for implants placement.

Purpose

This RCT was aimed to evaluate complications rate and vertical bone gain after Guided Bone Regeneration (GBR) with dense non‐resorbable d‐PTFE titanium‐reinforced membranes (Group A) versus titanium meshes covered by cross‐linked collagen membranes (Group B).

Material and Methods

40 partially edentulous patients with atrophic posterior mandible, were randomly divided into two study group: 20 patients were treated with one stage GBR by means of non‐resorbable d‐PTFE titanium‐reinforced membranes (Group A); and 20 patients, by means of titanium mesh covered by cross‐linked collagen membranes (Group B). All complications were recorded, distinguishing between “surgical” and “healing” and between “minor” or “major.”. Primary implants stability and vertical bone gain were also evaluated.

Results

In the group A, surgical and healing complication rates were 5.0% and 15.0%, respectively. In the group B, surgical and healing complication rates were 15.8% and 21.1%, respectively. No significant differences between two study group were observed regarding complications rate implant stability and vertical bone gain.

Conclusions

Both GBR approaches for the restoration of atrophic posterior mandible achieved similar results regarding complications, vertical bone gain and implant stability.