Vertical-guided bone regeneration with a titanium-reinforced d-PTFE membrane utilizing a novel split-thickness flap design: a prospective case series

Advances in Synthetic Polymer Membranes for Guided Bone Regeneration in Dental Implants: A Scoping Review

BACKGROUND

Different approaches are proposed for bone volume gain in the case of atrophic alveolar ridges, with guided bone regeneration (GBR) and guided tissue regeneration (GTR) being the most used techniques. These techniques require the placement of barrier membranes, which is the main element of the bone growth strategy, among which there is a wide range depending on their origin or degradation. This literature review aims to provide an update on the latest advances in polymeric membranes of synthetic origin currently used in bone regeneration.

MATERIALS AND METHODS

Two bibliographic searches were carried out in the PubMed (MEDLINE) and Scopus databases using a search strategy in which inclusion and exclusion criteria were applied.

RESULTS

For the selection of articles, the PRISMA guide flow chart was followed, and after a selection process, 11 articles were analyzed based on the characteristics of the marketed membranes and the results obtained after their use.

CONCLUSIONS

It can be concluded that polymeric membranes play a fundamental role in guided bone regeneration, providing an effective barrier that facilitates bone growth and improves the success of dental implantology treatments.

Autogenous solid dentin for horizontal ridge augmentation with simultaneous implantation in a severe bone defect: A 3.5-year follow-up clinical report

Autogenous dental root placement is an available approach for horizontal alveolar ridge augmentation in patients with severe bony defects. However, in previous reports, bone augmentation has been done before the implant placement. This clinical report describes the use of dentin grafting for alveolar ridge augmentation and simultaneous implant placement in the maxillary left central incisor region with a severe horizontal bone defect. Under strict adherence to the recommended indications, dentin grafting and simultaneous implantation could be clinically feasible protocols.

Regenerative approaches in alveolar bone augmentation for dental implant placement: Techniques, biomaterials, and clinical decision-making: A comprehensive review

OBJECTIVES

This review aimed to evaluate the outcomes of ridge augmentation techniques and bio-materials for alveolar bone regeneration, addressing inconsistencies across studies. A decision tree is provided to guide clinicians in selecting optimal approaches for diverse clinical scenarios.

DATA AND SOURCES

An extensive search was conducted across electronic databases, including PubMed, Scopus, and Embase, alongside dental implant and prosthodontics journal portals. Reference lists of relevant articles were also manually reviewed up to October 2024.

STUDY SELECTION

Inclusion criteria were established to emphasize English-language human clinical trials investigating regenerative techniques and materials utilized for ridge augmentation prior to implant placement.

CONCLUSIONS

Selecting defect-specific regenerative approaches is crucial for successful outcomes in alveolar bone augmentation. While autografts remain the gold standard, advancements in allografts, xenografts, synthetics, and biological enhancers are transforming the field. Distraction osteogenesis is also gaining prominence as a promising technique. Clinicians should leverage these innovations to tailor treatments to individual patient needs for optimal results. The decision tree developed categorizes alveolar bone defects and suggests tailored approaches based on anticipated resorption patterns.

CLINICAL SIGNIFICANCE

Careful patient evaluation and tailored technique selection, combined with advancements in biomaterials and tissue engineering, are essential for achieving optimal outcomes in ridge augmentation, particularly for challenging vertical defects.

Polymers for Osmotic Self-Inflating Expanders in Oral Surgical Procedures: A Comprehensive Review

Soft-tissue expansion is a critical challenge in regenerative oral surgeries. This scoping review maps the research on polymers used in osmotic self-inflating expanders, assessing their applications, characteristics, and potential in oral surgical procedures. The study analyzed 19 articles from the PubMed, Scopus, Web of Science, and Embase databases, primarily focusing on in vivo research (78.9%) investigating polymeric tissue expanders. The review examined polymer compositions, methodologies, and tissue responses across various animal models. Osmed® hydrogel was the most studied material, with research exploring its expansion capabilities in rabbits, goats, pigs, rats, and beagle dogs. The findings showed diverse tissue expansion ranges and minimal inflammatory responses, indicating the potential for oral surgical applications. Despite promising results, gaps such as inconsistent expansion measurements and the lack of standardized protocols were identified. These findings highlight the need for further research to develop new polymer formulations and optimize device design to enhance safety, efficacy, and clinical predictability. This review provides a foundation for advancing polymeric tissue expander technologies, offering the potential for safer and more effective minimally invasive regenerative oral surgeries.

Vertical Ridge Augmentation Using Deproteinized Bovine Bone Material Without Covering With a Membrane: A Tunnel Pouch Technique-4-Year Follow-up-A Pilot Clinical Study

The present pilot clinical trial was planned to evaluate the effect of particulate deproteinized bovine bone graft mixed with blood used as a vertical ridge augmentation material without covering with any form of collagen membrane in a tunnel pouch technique, resulting in sufficient bone formation to allow placement of dental implants with maintenance of the newly formed bone after final restoration. Eight patients (3 males and 5 females) were selected for this procedure and treated between February 2016 and December 2017. All these patients had a deficient vertical height of the posterior mandibular alveolar bone above the inferior alveolar canal. The particulate deproteinized organic bovine bone graft (Bio-Oss) mixed with blood was placed through the tunnel in the defected area and compacted firmly to form a dense pack. The average gain of alveolar bone in the first implant site immediately postoperative was 13.51 ± 0.85 and in the second implant site was 13.84 ± 0.62. Histomorphometric analysis showed that about 70.31% of the area analyzed was occupied by the vital bone, the newly formed bone, whereas only 29.69% of the residual graft remained. In the present pilot study, the deproteinized bovine bone graft placed to enhance vertical and horizontal bone gain showed positive results in regaining the bone needed to place implants and maintaining the bone around restored implants for 4 years of follow-up.

Long-Term Survival in Grafted Sites of Dental Implants

OBJECTIVE

Vertical and horizontal bone insufficiency in both the maxilla and mandible has long been a contraindication for implants. This review provides an overview of the long-term survival rates of implants in augmented alveolar bone after the guided bone regeneration (GBR) technique.

RESULTS

GBR in a combination of allogeneic or xenogeneic graft material with a barrier membrane and simultaneous or delayed placement of dental implants has proven to be a very effective and feasible treatment option in long-term studies up to 35 years.

CONCLUSION

Bone reconstruction with various materials is a standard therapy in implantology today.

Assessment of hard tissue changes after horizontal guided bone regeneration with the aid of deep learning CBCT segmentation

OBJECTIVES

To investigate the performance of a deep learning (DL) model for segmenting cone-beam computed tomography (CBCT) scans taken before and after mandibular horizontal guided bone regeneration (GBR) to evaluate hard tissue changes.

MATERIALS AND METHODS

The proposed SegResNet-based DL model was trained on 70 CBCT scans. It was tested on 10 pairs of pre- and post-operative CBCT scans of patients who underwent mandibular horizontal GBR. DL segmentations were compared to semi-automated (SA) segmentations of the same scans. Augmented hard tissue segmentation performance was evaluated by spatially aligning pre- and post-operative CBCT scans and subtracting preoperative segmentations obtained by DL and SA segmentations from the respective postoperative segmentations. The performance of DL compared to SA segmentation was evaluated based on the Dice similarity coefficient (DSC), intersection over the union (IoU), Hausdorff distance (HD95), and volume comparison.

RESULTS

The mean DSC and IoU between DL and SA segmentations were 0.96 ± 0.01 and 0.92 ± 0.02 in both pre- and post-operative CBCT scans. While HD95 values between DL and SA segmentations were 0.62 mm ± 0.16 mm and 0.77 mm ± 0.31 mm for pre- and post-operative CBCTs respectively. The DSC, IoU and HD95 averaged 0.85 ± 0.08; 0.78 ± 0.07 and 0.91 ± 0.92 mm for augmented hard tissue models respectively. Volumes mandible- and augmented hard tissue segmentations did not differ significantly between the DL and SA methods.

CONCLUSIONS

The SegResNet-based DL model accurately segmented CBCT scans acquired before and after mandibular horizontal GBR. However, the training database must be further increased to increase the model's robustness.

CLINICAL RELEVANCE

Automated DL segmentation could aid treatment planning for GBR and subsequent implant placement procedures and in evaluating hard tissue changes.

Secured Anatomy-Driven Flap Extension (SAFE) for Guided Bone Regeneration: A Modified Flap Release Technique Description and Retrospective Study

Current flap-releasing designs for guided bone regeneration (GBR) emphasize preserving subperiosteal microvasculature by adapting a deep-slit approach, separating the periosteum from the flap. Although biologically sound, a biomechanical disadvantage may be encountered. This study aimed to describe a modified design, the Secured Anatomy-driven Flap Extension (SAFE) technique, for effective facial flap release and to preliminarily evaluate the clinical outcomes of this technique retrospectively. Chart reviews were conducted to identify patients treated by facial flap release in staged GBR procedures between May 2020 and March 2022. The anatomical, biological, and biomechanical rationale of this technique were described. The following clinical data were collected: intraoperative and postoperative complications, initial and final horizontal ridge width before and 5-6 months after the GBR, and implant performance. A total of 10 patients were identified. At baseline, these patients presented with a mean ridge width of 2.05 ± 0.52 mm. No intraoperative and postoperative complications were observed in these patients (bleeding, wound opening, neurosensory disturbance, etc.) at the 2-3-week follow-up visit. At the re-entry, a mean ridge width of 6.50 ± 0.55 mm was measured (P < .01), resulting in a mean of 4.45 ± 0.65 mm ridge width gain. Twenty-one implants were successfully placed, integrated, and in function without signs/symptoms of peri-implantitis after a mean 21.5 ± 9.2 months follow-up period. Preliminary results suggest that the SAFE technique is a safe and predictable approach for releasing facial flaps during GBR procedures.

A Flexible Membrane May Improve Bone Regeneration by Increasing Hydrophilicity and Conformability in Lateral Bone Augmentation

Collagen membranes play a crucial role in guided bone regeneration (GBR) by preventing soft tissue infiltration and maintaining space for bone formation. This study investigated the impact of collagen membrane flexibility on GBR outcomes through in vitro and in vivo analyses. Flexible (0.3 mm in width) and stiff (0.5 mm in width) porcine collagen membranes were compared. In vitro tests assessed hydrophilicity, enzymatic degradation, conformability, space maintenance, and tensile strength. An in vivo study using a canine model evaluated bone regeneration in standardized mandibular defects filled with deproteinized porcine bone mineral and covered with no membrane, flexible membrane, or stiff membrane. Micro-computed tomography and histomorphometric analyses were performed at 8 and 16 weeks. The flexible membrane demonstrated superior hydrophilicity, faster enzymatic degradation, and greater conformability in vitro. In vivo, micro-computed tomography analysis revealed similar alveolar ridge widths across all groups. Histomorphometric analysis at 16 weeks showed significantly larger regenerated areas in the flexible membrane group compared to controls in coronal, middle, and apical regions. Both membrane groups exhibited higher regeneration ratios than controls, with significant differences in the coronal area. The flexible membrane group demonstrated significantly higher new bone formation in all regions compared to controls at 16 weeks. These findings suggest that flexible membrane substantially enhances GBR outcomes by increasing hydrophilicity and conformability. The study highlights the potential clinical benefits of incorporating flexible membranes in GBR procedures for improved bone regeneration outcomes.

β-Tricalcium phosphate incorporated natural rubber latex membranes for calvarial bone defects: Physicochemical, in vitro and in vivo assessment

Natural rubber latex membrane (NRL) is a biocompatible macromolecule that stimulates angiogenesis and promotes bone repair. Similarly, β-tricalcium phosphate (β-TCP) is an osteoconductive and osteoinductive bioceramic widely used as a bone substitute. Here, we investigated the combined use of these biomaterials in the guided bone regeneration process for calvarial defects in rats. Physicochemical characterization was performed to evaluate the interaction between β-TCP and NRL. Membrane toxicity was assessed using MC3T3 osteoblasts culture and in vivo assays with Caenorhabditis elegans. Lastly, NRL membranes, NRL incorporated with β-TCP membranes (NRL-β-TCP), and a periosteum-only (control group) were tested on rodents. MC3T3 cells adhered to membranes, preserving their morphology and intercellular connections. NRL-β-TCP membranes demonstrated no toxicity in larvae, which maintained their sinusoidal wave shape. Tests results on rodents revealed statistical difference between the groups at 60 days post-operation. NRL-β-TCP (56.1 ± 14.0 %) had an average 1.48-fold higher than the control group (38.0 ± 9.1 %), with tissue production and bone remodeling. Our qualitative histological analyses revealed that membranes significantly accelerated bone formation without any signs of inflammatory reactions. We conclude that NRL-β-TCP has potential to be used for flat bone regeneration, with osteoconductive properties, being a cheap, biocompatible, and effective occlusive barrier.

Complication rates of guided bone regeneration using titanium-reinforced PTFE membranes: a retrospective analysis

INTRODUCTION

This study analyzed complication rates of guided bone regeneration (GBR) using titanium-reinforced polytetrafluoroethylene (PTFE) membranes for alveolar ridge augmentation.

MATERIAL AND METHODS

84 patients treated with GBR using titanium-reinforced PTFE membranes (91 sites) were retrospectively analyzed. Complications such as membrane exposure and early removal were analyzed concerning patient age, defect site position, size, simultaneous vs. two-stage implant placement, smoking, and the use of bone grafts (BG) and substitutes (BS).

RESULTS

Early removal due to membrane exposure was necessary in 14/91 sites (15.4%). No correlation was found between early removal and patient age (p = 0.917). Analyzing early removal between the upper and lower jaw and between both jaws' anterior and posterior tooth regions revealed no correlations (p = 0.381 and 0.477, respectively). Defect sites sizes of 5-6 mm exhibited the highest rate of membrane exposure, requiring early removal, accounting for 57.1% of these sites (8/14). No correlation was observed between the defect sites size and early removal (p = 0.660). Comparison of simultaneous (74 sites) vs. two-stage implant placement (16 sites) showed no correlation with early removal (p = 0.706). Membrane exposure incidence was 42.9% among smokers (27 patients, 32.1%) and 57.1% among non-smokers (57 patients, 67.9%), without correlation. No correlation was found between the type of BG and BS and early removal (p = 0.500).

CONCLUSION

GBR using titanium-reinforced PTFE membranes is effective for alveolar ridge augmentation and has favorable long-term outcomes.

CLINICAL RELEVANCE

Careful surgical technique and postoperative care can minimize the notable risk of PTFE membrane exposure.

An Integrated Dual-Layer Heterogeneous Polycaprolactone Scaffold Promotes Oral Mucosal Wound Healing through Inhibiting Bacterial Adhesion and Mediating HGF-1 Behavior

Recently, the high incidence of oral mucosal defects and the subsequent functional impairments have attracted widespread attention. Controlling scaffold geometry pattern has been proposed as a strategy to promote cell behavior and facilitate soft tissue repair. In this study, we innovatively construct an integrated dual-layer heterogeneous polycaprolactone (PCL) scaffold using melt electrowriting (MEW) technology. The outer layer was disordered, while the inner layer featured oriented fiber patterns: parallel (P-par), rhombic (P-rhomb), and square (P-sq). Our findings revealed that the P-rhomb and P-sq scaffolds exhibited superior surface wettability, roughness, and tensile strength compared to the pure disordered PCL scaffolds (P) and P-par. Compared to the commercial collagen membranes, the outer layer of PCL can effectively inhibit bacterial adhesion and biofilm formation. Furthermore, the P-rhomb and P-sq groups demonstrated higher gene and protein expression levels related to cell adhesion and cell migration rates than did the P and P-par groups. Among them, P-sq plays an important role in inducing the differentiation of gingival fibroblasts into myofibroblasts rich in α-smooth muscle actin (α-SMA). Additionally, P-sq could reduce inflammation, promote epithelial regeneration, and accelerate wound healing when used in full-thickness oral mucosal defects in rabbits. Overall, the integrated dual-layer heterogeneous PCL scaffold fabricated by MEW technology effectively inhibited bacterial adhesion and guided tissue regeneration, offering advantages for clinical translation and large-scale production. This promising material holds important potential for treating full-thickness mucosal defects in a bacteria-rich oral environments.

Advancements in dental implantology: The alveolar ridge split technique for enhanced osseointegration

The alveolar ridge split (ARS) technique is a pivotal advancement in dental implantology, addressing the limitation of insufficient bone width for implant placement. This review traces the historical development of ARS from its initial conceptualization to current practices and future directions. Emphasizing the technique's development, indications, procedural overview, and osteotomy variations, we highlight its minimally invasive nature, which reduces patient morbidity and treatment time. This article reviews various osteotomy methods within ARS, examining their applications, benefits, and limitations. Furthermore, it discusses the technique's role in expanding treatment options for patients with compromised alveolar structures, underpinned by a high implant survival rate and the potential for immediate implant placement. We also cover the necessity of meticulous surgical technique, the importance of patient-specific factors, and the promising future of ARS facilitated by advancements in biomaterials and regenerative medicine. In summary, this review provides a comprehensive overview of ARS, offering valuable insights for dental professionals and informing future clinical practices and research in implantology.

Changes in soft tissue dimensions following horizontal guided bone regeneration with a split-thickness flap design - evaluation of 8 cases with a digital method

BACKGROUND

Peri-implant soft tissue corrections are often indicated following alveolar ridge augmentation, due to the distortion of the keratinized mucosa at the area of augmentation. The objective of the current study was to evaluate the dimensional soft tissue changes following horizontal guided bone regeneration (GBR) utilizing 3D digital data.

METHODS

8 mandibular surgical sites with horizontal alveolar ridge deficiencies were treated utilizing a resorbable collagen membrane and a split-thickness flap design. Baseline and 6-month follow-up cone-beam computed tomography (CBCT) scans were reconstructed as 3D virtual models and were superimposed with the corresponding intraoral scan. Linear changes of supracrestal vertical- horizontal soft tissue alterations were measured in relation to the alveolar crest at the mesial- middle- and distal aspect of the surgical area. Soft tissue dimensions were measured at baseline and at 6-month follow-up.

RESULTS

Preoperative supracrestal soft tissue height measured midcrestally averaged at 2.37 mm ± 0.68 mm, 2.37 mm ± 0.71 mm and 2.64 mm ± 0.87 mm at the mesial-, middle- and distal planes. Whereas postoperative supracrestal soft tissue height was measured at 2.62 mm ± 0.72 mm, 2.67 mm ± 0.67 mm and 3.69 mm ± 1.02 mm at the mesial, middle and distal planes, respectively. Supracrestal soft tissue width changed from 2.14 mm ± 0.72 mm to 2.47 mm ± 0.46 mm at the mesial, from 1.72 mm ± 0.44 mm to 2.07 mm ± 0.67 mm and from 2.15 mm ± 0.36 mm to 2.36 mm ± 0.59 mm at the mesial, middle and distal planes, respectively. Additionally the buccal horizontal displacement of supracrestal soft tissues could be observed.

CONCLUSIONS

The current study did not report significant supracrestal soft tissue reduction following horizontal GBR with a split-thickness flap. Even though there was a slight increase in both vertical and horizontal dimensions, differences are clinically negligible.

TRAIL REGISTRATION

The trail was approved by the U.S. National Library of Medicine ( www.

CLINICALTRIALS

gov ); trial registration number: NCT05538715; registration date: 09/09/2022.

Linear bone gain and healing complication rate comparative outcomes following ridge augmentation with custom 3D printed titanium mesh vs Ti-reinforced dPTFE. A randomized clinical trial

AIM

The aim of this randomized clinical trial was to compare the qualitative (linear alveolar ridge changes) and quantitative (healing complications) outcomes after guided bone regeneration (GBR) using a custom-made 3D printed titanium mesh versus titanium reinforced dense PTFE membrane for vertical and horizontal augmentation of deficient alveolar ridges.

Internal Allo-Cortical Tenting: A Modified Ridge Split Technique in Three-Dimensional Ridge Augmentation

Three-dimensional (3D) alveolar ridge deficiencies necessitate horizontal and vertical bone reconstruction for optimal implant positioning. Despite several available techniques, achieving desired augmentation outcomes remains challenging. This case study aims to present a modified ridge split technique for bone reconstruction in horizontal and vertical dimensions. The proposed technique was used to reconstruct the horizontal and vertical ridge defect from removing a previously failed implant. This technique includes placing a cortical allograft plate as an internal tent in the split ridge. A portion of the plate was inserted into the ridge, while the other part was placed in the coronal of the vertical defect. Additional guided bone regeneration was performed around the tented plate on both the buccal and lingual sides. After 5 months, cone beam computerized tomography revealed sufficient bone formation in horizontal and vertical dimensions. Within the limitations of the present case study, internal cortical tenting would be a reliable method for 3D bone reconstruction in cases where the ridge split is feasible.

Matrix Metalloproteinase 9 (MMP-9) and Interleukin-8 (IL-8) in Gingival Crevicular Fluid after Minimally Invasive Periodontal Surgery with or without Er:YAG and Nd:YAG Laser Application

BACKGROUND

This study aimed to evaluate alterations in the concentrations of matrix metalloproteinase-9 (MMP-9) and interleukin-8 (IL-8) within gingival crevicular fluid (GCF) extracted from the intrabony periodontal defect site before and after minimally invasive regenerative surgery, with or without supplemental laser application. The surgical procedure was performed using the modified minimally invasive surgical technique (M-MIST).

METHODS

Thirty-eight patients, each presenting with a single vertical defect, were randomly assigned to either the test (M-MIST + Er:YAG + Nd:YAG) or the control group (M-MIST). IL-8 and MMP-9 levels (primary outcomes of the study) were assessed prior to therapy, after 2 and 4 weeks, and 6 months following the surgical procedure by means of dedicated ELISA kits.

RESULTS

Both procedures were clinically effective as evidenced by probing depth (PD) reduction and clinical attachment level (CAL) gain at the 6-month follow-up. No statistical differences were observed in the levels of MMP-9 and IL-8 between the groups at any time point assessed. The changes in the level of MMP-9 and IL-8 over time were not statistically significant in any group. IL-8 was positively correlated with MMP-9 in the control group throughout the study and in the test group 2 weeks and 6 months post-op.

CONCLUSIONS

Within the limitations of this study, the additional application of Er:YAG + Nd:YAG lasers alongside the M-MIST procedure did not enhance the clinical and biochemical treatment outcomes compared to M-MIST alone.

Developments in Alloplastic Bone Grafts and Barrier Membrane Biomaterials for Periodontal Guided Tissue and Bone Regeneration Therapy

Periodontitis is a serious form of oral gum inflammation with recession of gingival soft tissue, destruction of the periodontal ligament, and absorption of alveolar bone. Management of periodontal tissue and bone destruction, along with the restoration of functionality and structural integrity, is not possible with conventional clinical therapy alone. Guided bone and tissue regeneration therapy employs an occlusive biodegradable barrier membrane and graft biomaterials to guide the formation of alveolar bone and tissues for periodontal restoration and regeneration. Amongst several grafting approaches, alloplastic grafts/biomaterials, either derived from natural sources, synthesization, or a combination of both, offer a wide variety of resources tailored to multiple needs. Examining several pertinent scientific databases (Web of Science, Scopus, PubMed, MEDLINE, and Cochrane Library) provided the foundation to cover the literature on synthetic graft materials and membranes, devoted to achieving periodontal tissue and bone regeneration. This discussion proceeds by highlighting potential grafting and barrier biomaterials, their characteristics, efficiency, regenerative ability, therapy outcomes, and advancements in periodontal guided regeneration therapy. Marketed and standardized quality products made of grafts and membrane biomaterials have been documented in this work. Conclusively, this paper illustrates the challenges, risk factors, and combination of biomaterials and drug delivery systems with which to reconstruct the hierarchical periodontium.

Effects of intentional early dense-polytetrafluoroethylene membrane removal on vertical ridge augmentation

BACKGROUND

Vertical ridge augmentation (VRA) requires long healing times for bone maturation. This case study deals with the intentional early removal of a titanium-reinforced dense polytetrafluoroethylene (TR-dPTFE) membrane that allowed for treatment times reduction and improvement of bone quality.

METHODS

A TR-dPTFE membrane was used for VRA in the premolar 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. After a 4-month uneventful healing period, the membrane was removed, and the thick keratinized palatal tissue was moved toward the buccal side via a pedicle flap. Implants insertion and healing abutments application were carried out 3 months later, when bone graft could have been revascularized and nourished by the periosteum.

RESULTS

The histologic evaluation of a bone sample harvested during implant bed preparation revealed a huge amount of mature newly formed bone even in the most coronal part. Two screw-retained crowns were delivered 2 months after implant insertion and the 3.5-year follow-up showed perfectly maintained hard and soft tissues.

CONCLUSIONS

Intentional early removal of TR-dPTFE membrane after a 4-month healing time, with simultaneous soft tissue augmentation via a buccally reposioned pedicle flap, allowed graft revascularization from the periosteum, and resulted in optimal quantity and quality of the regenerated bone. This process shortened the overall treatment times, taking only 9 months from VRA to prosthetic loading. Both augmented hard and soft tissues allowed for crestal bone maintenance around implants.

KEY POINTS

Titanium-reinforced dense polytetrafluoroethylene (TR-dPTFE) membranes, due to their closed structure, do not allow the passage of cells and vessels from the periosteum, and revascularization from the residual bone alone is not enough for proper graft maturation and long-term crestal bone maintenance. Early removal of TR-dPTFE membrane allows graft revascularization from the periosteum, and results in optimal quantity and quality of the regenerated bone. Increasing the thickness of the soft tissues, increasing the width of the keratinized mucosa, and repositioning the mucogingival line, via a free gingival graft or a pedicle flap, should be performed simultaneously in the membrane removal phase to reduce the number of surgical interventions, decrease patient morbidity, and shorten the total treatment time.

Healing of Extraction Sites after Alveolar Ridge Preservation Using Advanced Platelet-Rich Fibrin: A Retrospective Study

BACKGROUND

Over time, numerous surgical procedures and biomaterials have been proposed for the reconstruction of post-extraction bone defects, each with their advantages and disadvantages. The main objective of this study was to evaluate dimensional changes in the alveolar bone 3 months after tooth extraction, before implant planning, comparing alveolar ridge preservation (ARP) with spontaneous healing.

METHODS

A total of 84 patients with non-restorable molars were included in the study. Forty-two patients received ARP with advanced platelet-rich fibrin (A-PRF) and spontaneous healing was evaluated in these patients. Cone beam computed tomography (CBCT) analysis performed before and after surgical intervention was used to determine the changes in vertical and horizontal bone dimensions produced after tooth extraction.

RESULTS

CBCT measurements showed reduction in both vertical and horizontal alveolar bone size in both groups. For the study group, the alveolar parameters (height, width) were higher compared to the control group. The percentage variations between dimensional differences from the two groups were 38.58% for height, and for width were 36.88% at 0 mm, 35.56% at 3 mm, 36.61% at 5 mm, and 38.73% at 7 mm. The differences were statistically significant (p ˂ 0.0005).

CONCLUSIONS

The results obtained after ARP with A-PRF showed a reduced loss of bone volume compared to spontaneous healing.

Comparison of Khoury's Bone Shell Technique vs Titanium-reinforced Polytetrafluoroethylene Membrane for 3D-bone Augmentation in Atrophic Posterior Mandible: A Randomized Clinical Trial

AIM

This study was designed to compare between the use of Khoury's bone shell technique vs titanium-reinforced PTFE membrane for 3D-ridge augmentation of atrophic posterior mandible.

MATERIALS AND METHODS

Sixteen patients were equally and randomly assigned to either the Khoury or PTFE group. In Khoury group, a mandibular bone block was harvested, split and then fixed to augment the mandibular defect using osteosynthesis screws. In PTFE group, augmentation was achieved using Titanium-reinforced PTFE membranes fixed with bone tacks/screws. A mixture of autogenous and xenogenic graft material at a 1:1 ratio was used in both groups. Vertical and horizontal bone gain were obtained using cone-beam computed tomography (CBCT). Preoperative dimensions were compared with the final dimensions obtained 6 months postoperatively.

RESULTS

No significant complications or neurosensory dysfunction were encountered. A solitary patient in the Khoury group experienced limited wound dehiscence, which was treated conservatively. For both groups, there were no significant differences between preoperative and postoperative vertical (p = 0.849 and 0.569) and horizontal (p = 0.778 and 0.367) dimensions.

CONCLUSION

No significant differences exist between the augmentation dimension which can be obtained using either Khoury of Ti-PTFE membranes.

CLINICAL SIGNIFICANCE

Both approaches are delicate and necessitate surgical expertise and experience. Both techniques can be used to achieve predictable augmentation results with a low rate of complications. How to cite this article: Shaker AES, Salem AS, El-Farag SAA, et al. Comparison of Khoury's Bone Shell Technique vs Titanium-reinforced Polytetrafluoroethylene Membrane for 3D-bone Augmentation in Atrophic Posterior Mandible: A Randomized Clinical Trial. J Contemp Dent Pract 2024;25(6):518-526.

A review on guided bone regeneration using titanium mesh

The gold standard for bone regeneration in atrophic ridge patients is guided bone regeneration (GBR). This makes it possible to get enough bone volume for an appropriate implant-prosthetic rehabilitation. The barrier membranes must meet the primary GBR design requirements, which include adequate integration with the surrounding tissue, spaciousness and clinical manageability. Titanium mesh's superior mechanical qualities and biocompatibility have broadened the indications of GBR technology, enabling it to be used to restore alveolar ridges with more significant bone defects. GBR with titanium mesh is being used in many clinical settings and for a range of clinical procedures. Furthermore, several advancements in digitalization and material modification have resulted from the study of GBR using titanium mesh. Hence, we report a review on the various characteristics of titanium mesh and its current use in clinical settings for bone augmentation.

Dual Mg-Reinforced PCL Membrane with a Janus Structure for Vascularized Bone Regeneration and Bacterial Elimination

Commercially available guided bone regeneration (GBR) membranes often exhibit limited mechanical properties or bioactivity, leading to poor performance in repairing bone defects. To surmount this limitation, we developed a Janus structural composite membrane (Mg-MgO/PCL) reinforced by dual Mg (Mg sheets and MgO NPs) by using a combined processing technique involving casting and electrospinning. Results showed that the addition of Mg sheets and MgO NPs enhanced the mechanical properties of the composite membrane for osteogenic space maintenance, specifically tensile strength (from 10.2 ± 1.2 to 50.3 ± 4.5 MPa) and compression force (from 0 to 0.94 ± 0.09 N mm-1), through Mg sheet reinforcement and improved crystallization. The dense cast side of the Janus structure membrane displayed better fibroblast barrier capacity than a single fiber structure; meanwhile, the PCL matrix protected the Mg sheet from severe corrosion due to predeformation. The porous microfibers side supported preosteoblast cell adhesion, enhanced osteogenesis, and angiogenesis in vitro, through the biomimetic extracellular matrix and sustainable Mg2+ release. Furthermore, the Mg-MgO/PCL membrane incorporating 2 wt % MgO NPs exhibited remarkable antimicrobial properties, inducing over 88.75% apoptosis in Staphylococcus aureus. An in vivo experiment using the rat skull defect model (Φ = 5 mm) confirmed that the Mg-MgO/PCL membrane significantly improved new bone formation postsurgery. Collectively, our investigation provides valuable insights into the design of multifunctional membranes for clinical oral GBR application.

The application of CGF combined with GBR in alveolar bone increment for patients with anxiety disorder: A rare case report and literature review

RATIONALE

Selective serotonin reuptake inhibitors (SSRIs), one of the commonly used anti-anxiety drugs, may have impacts on bone metabolism and potentially lead to drug-induced osteoporosis. The traditional approach of oral implantation in individuals with both anxiety disorder and drug-induced osteoporosis poses a significant challenge. To address this issue, concentrated growth factor (CGF) has been utilized in patients undergoing concurrent alveolar ridge augmentation during oral implantation, resulting in favorable clinical outcomes. Consequently, combining CGF with guided bone regeneration (GBR) in alveolar bone increment may represent a promising new surgical approach for such patients. In this report, we present a case study of a 25-year-old male with anxiety disorder and drug-induced osteoporosis, in who CGF combined with GBR was employed in alveolar bone increment.

PATIENT CONCERNS

This article reports the case of a 25-year-old male who underwent cone beam computed tomography (CBCT) due to the absence of his right lower second molar for a period of six months. The CBCT scan revealed significant bone defects, which were attributed to the tooth loss and prolonged use of anti-anxiety drugs. Consequently, the patient sought medical assistance from our department.

DIAGNOSES

Based on the patient's self-report, he was diagnosed with an anxiety disorder. Additionally, the CBCT scan confirmed the loss of the right mandibular second molar and revealed the presence of dental irregularity and an alveolar bone defect.

INTERVENTIONS

During the patient's course of treatment with anti-anxiety medication, a combination of CGF and GBR was employed for the simultaneous implantation of the missing right mandibular second molar, along with bone augmentation.

OUTCOMES

The patient had a follow-up visit two weeks after the surgical procedure, and the wound in the operation area had healed satisfactorily. Six months later, CBCT images revealed excellent osseointegration. The buccal and lingual width of the alveolar bone measured 6.95mm, which was an increase of 1.35mm compared to the pre-implantation stage.

LESSONS

This article presents a case study in which CGF combined with GBR were utilized to address alveolar bone augmentation during the implantation phase in patients taking anti-anxiety medication. The results demonstrated that CGF combined with GBR, as a cutting-edge platelet concentrate technique, could effectively stimulate bone tissue proliferation in individuals who have been on long-term anti-anxiety medication, specifically in oral implant areas. This approach can help prevent poor osseointegration, promote higher osseointegration rates, and facilitate wound healing.

Accumulative Rolling Mg/PLLA Composite Membrane with Lamellar Heterostructure for Enhanced Bacteria Inhibition and Rapid Bone Regeneration

Developing composite materials with optimized mechanics, degradation, and bioactivity for bone regeneration has long been a crucial mission. Herein, a multifunctional Mg/Poly-l-lactic acid (Mg/PLLA) composite membrane based on the "materials plain" concept through the accumulative rolling (AR) method is proposed. Results show that at a rolling ratio of 75%, the comprehensive mechanical properties of the membrane in the rolling direction are self-reinforced significantly (elongation at break ≈53.2%, tensile strength ≈104.0 MPa, Young's modulus ≈2.13 GPa). This enhancement is attributed to the directional arrangement and increased crystallization of PLLA molecular chains, as demonstrated by SAXS and DSC results. Furthermore, the AR composite membrane presents a lamellar heterostructure, which not only avoids the accumulation of Mg microparticles (MgMPs) but also regulates the degradation rate. Through the contribution of bioactive MgMPs and their photothermal effect synergistically, the membrane effectively eliminates bacterial infection and accelerates vascularized bone regeneration both in vitro and in vivo. Notably, the membrane exhibits outstanding rat skull bone regeneration performance in only 4 weeks, surpassing most literature reports. In short, this work develops a composite membrane with a "one stone, four birds" effect, opening an efficient avenue toward high-performance orthopedic materials.

Techniques on vertical ridge augmentation: Indications and effectiveness

Vertical ridge augmentation techniques have been advocated to enable restoring function and esthetics by means of implant-supported rehabilitation. There are three major modalities. The first is guided bone regeneration, based on the principle of compartmentalization by means of using a barrier membrane, which has been demonstrated to be technically demanding with regard to soft tissue management. This requisite is also applicable in the case of the second modality of bone block grafts. Nonetheless, space creation and maintenance are provided by the solid nature of the graft. The third modality of distraction osteogenesis is also a valid and faster approach. Nonetheless, owing to this technique's inherent shortcomings, this method is currently deprecated. The purpose of this review is to shed light on the state-of-the-art of the different modalities described for vertical ridge augmentation, including the indications, the step-by-step approach, and the effectiveness.

The Bone Bridge Technique Utilizing Bone from the Lateral Wall of the Maxillary Sinus for Ridge Augmentation: Case Reports of a 1-7 Year Follow-Up

The post-extraction socket of a periodontally compromised tooth/implant is oftentimes accompanied by a very wide-deep alveolar ridge defect. The commonly utilized treatment is ridge preservation followed by delayed implant placement 4 to 6 months after extraction. In the four cases presented in this study, a novel technique of utilizing a bone block obtained from the lateral wall of the maxillary sinus is introduced. Due to the severe localized vertical ridge deficiency, an intraoral autogenous bone block was obtained from the ipsilateral sinus bony window. After the obtained bone block was properly trimmed, it was fixed in the form of a bridge over the vertical defect by the press-fit method. In two cases, the gap between the autogenous bone and defect was filled with a particulate synthetic bone graft, and in another two cases, the gap was left without grafting. All cases were covered with a resorbable collagen membrane. At the time of re-entry after 5 to 6 months, the bone bridge was well incorporated beside the adjacent native bone and helped by the implant placement. Uncovering was performed after 3 to 6 months, and prostheses were delivered after 2 months. Oral function was maintained without any change in the marginal bone level even after the 1- to 7-year post-prosthesis delivery. This case series showed that the bone bridge technique performed using an ipsilateral sinus bony window for a localized vertical deficiency of a post-extraction socket can be used for successful vertical ridge augmentation (VRA).

Full-Digital Customized Meshes in Guided Bone Regeneration Procedures: A Scoping Review

Meshes, especially titanium ones, are being widely applied in oral surgery. In guided bone regeneration (GBR) procedures, their use is often paired with membranes, being resorbable or non-resorbable. However, they present some limitations, such as difficulty in the treatment of severe bone defects, alongside frequent mesh exposure. Customized meshes, produced by a full-digital process, have been recently introduced in GBR procedures. Therefore, the focus of the present review is to describe the main findings in recent years of clinical trials regarding patient-specific mesh produced by CAD/CAM and 3D printing workflow, made in titanium or even PEEK, applied to GBR surgeries. The purpose is to analyze their clinical management, advantages, and complications. This scoping review considered randomized clinical trials, observational studies, cohort studies, and case series/case reports studies. Studies that did not meet inclusion criteria were excluded. The preferred reporting items for scoping reviews (PRISMA-ScR) consensus was followed. A total of 15 studies were selected for this review. Based on the studies included, the literature suggests that meshes produced by a digital process are used to restore complex and severe bone defects. Moreover, they give satisfactory aesthetic results and fit the defects, counteracting grid exposure. However, more clinical trials should be conducted to evaluate long-term results, the rate of complications, and new materials for mesh manufacturing.

Guided Bone Regeneration with Occlusive Titanium Barrier: A Case Report and Clinical Considerations

The need to obtain adequate bone volumes for prosthetic rehabilitation supported by implants, using different techniques and materials, represents an urgent need in modern dentistry. We report a case regarding the management of implant-prosthetic rehabilitation of the first and second upper right molars, in which no less than 4 mm of crestal bone remained to insert two implants. Regeneration of the residual bone was previously performed using a customized titanium barrier and a filler of a blood clot with tricalcium beta phosphate. The bone gain (3 mm) was evaluated by comparing CBCT images, while the implant stability (mean 70) was assessed with the ISQ measurement. A regenerated bone sample was taken for histological analysis. Guided bone regeneration obtained with a titanium barrier and blood clot allowed for the insertion of stable implants in a mature bone without heterologous material.

Three-dimensional volumetric assessment of hard tissue alterations following horizontal guided bone regeneration using a split-thickness flap design: A case series

OBJECTIVES

To analyze morphological, volumetric, and linear hard tissue changes following horizontal ridge augmentation using a three-dimensional radiographic method.

METHODS

As part of a larger ongoing prospective study, 10 lower lateral surgical sites were selected for evaluation. Horizontal ridge deficiencies were treated with guided bone regeneration (GBR) using a split-thickness flap design and a resorbable collagen barrier membrane. Following the segmentation of baseline and 6-month follow-up cone-beam computed tomography scans, volumetric, linear, and morphological hard tissue changes and the efficacy of the augmentation were assessed (expressed by the volume-to-surface ratio).

RESULTS

Volumetric hard tissue gain averaged 605.32 ± 380.68 mm³. An average of 238.48 ± 127.82 mm³ hard tissue loss was also detected at the lingual aspect of the surgical area. Horizontal hard tissue gain averaged 3.00 ± 1.45 mm. Midcrestal vertical hard tissue loss averaged 1.18 ± 0.81 mm. The volume-to-surface ratio averaged 1.19 ± 0.52 mm³/mm². The three-dimensional analysis showed slight lingual or crestal hard tissue resorption in all cases. In certain instances, the greatest extent of hard tissue gain was observed 2-3 mm apical to the initial level of the marginal crest.

CONCLUSIONS

With the applied method, previously unreported aspects of hard tissue changes following horizontal GBR could be examined. Midcrestal bone resorption was demonstrated, most likely caused by increased osteoclast activity following the elevation of the periosteum. The volume-to-surface ratio expressed the efficacy of the procedure independent of the size of the surgical area.

The effect of bone defect size on the 3D accuracy of alveolar bone augmentation performed with additively manufactured patient-specific titanium mesh

OBJECTIVE

Additively manufactured (3D-printed) titanium meshes have been adopted in the dental field as non-resorbable membranes for guided bone regeneration (GBR) surgery. However, according to previous studies, inaccuracies between planned and created bone volume and contour are common, and many reasons have been speculated to affect its accuracy. The size of the alveolar bone defect can significantly increase patient-specific titanium mesh design and surgical difficulty. Therefore, this study aimed to analyze and investigate the effect of bone defect size on the 3D accuracy of alveolar bone augmentation performed with additively manufactured patient-specific titanium meshes.

METHODS

Twenty 3D-printed patient-specific titanium mesh GBR surgery cases were enrolled, in which 10 cases were minor bone defect/augmentation (the planned bone augmentation surface area is less than or equal to 150 mm² or one tooth missing or two adjacent front-teeth/premolars missing) and another 10 cases were significant bone defect/augmentation (the planned bone augmentation surface area is greater than 150 mm² or missing adjacent teeth are more than two (i.e. ≥ three teeth) or missing adjacent molars are ≥ two teeth). 3D digital reconstruction/superposition technology was employed to investigate the bone augmentation accuracy of 3D-printed patient-specific titanium meshes.

RESULTS

There was no significant difference in the 3D deviation distance of bone augmentation between the minor bone defect/augmentation group and the major one. The contour lines of planned-CAD models in two groups were basically consistent with the contour lines after GBR surgery, and both covered the preoperative contour lines. Moreover, the exposure rate of titanium mesh in the minor bone defect/augmentation group was slightly lower than the major one.

CONCLUSION

It can be concluded that the size of the bone defect has no significant effect on the 3D accuracy of alveolar bone augmentation performed with the additively manufactured patient-specific titanium mesh.

The use of periodontal membranes in the field of periodontology: spotlight on collagen membranes

Periodontal regenerative techniques are performed to accomplish the restitution of soft and hard teeth-supporting tissues that have been lost due to trauma or inflammatory disease. Periodontal membranes are used for these techniques to provide support and a framework for cell growth and tissue regeneration. They act as a temporary and selective barrier to cell proliferation. Easy clinical handling, biomechanical specifications, high biocompatibility, cell-occlusivity, and satisfactory bioresorption rate are essential properties a membrane needs to be effective. The creation and maintenance of a secluded space is also a fundamental rule in periodontal regenerative techniques. The use of barrier membranes in the field of restorative dentistry has progressed toward the use of minimally invasive approaches optimizing wound closure and limiting patient morbidity. This review intends to provide an overview of the major cellular events in the surgical wound and membrane surface. It was also performed to assess, from literature data, the pertinence of using non-resorbable and resorbable membranes for this regenerative purpose. Special attention will be given to collagen membranes.

Reconstruction of vertical alveolar ridge deficiencies utilizing a high-density polytetrafluoroethylene membrane /clinical impact of flap dehiscence on treatment outcomes: case series/

Objectives

The aim of this study was to evaluate the effects of membrane exposure during vertical ridge augmentation (VRA) utilizing guided bone regeneration with a dense polytetrafluoroethylene (d-PTFE) membrane and a tent-pole space maintaining approach by registering radiographic volumetric, linear and morphological changes.

Methods

In 8 cases alveolar ridge defects were accessed utilizing a split-thickness flap design. Following flap elevation VRA was performed with tent-pole space maintaining approach utilizing the combination of a non-reinforced d-PTFE membrane and a composite graft (1:1 ratio of autogenous bone chips and bovine derived xenografts). Three-dimensional radiographic evaluation of hard tissue changes was carried out with the sequence of cone-beam computed tomography (CBCT) image segmentation, spatial registration and 3D subtraction analysis.

Results

Class I or class II membrane exposure was observed in four cases. Average hard tissue gain was found to be 0.70 cm3 ± 0.31 cm3 and 0.82 cm3 ± 0.40 cm3 with and without membrane exposure resulting in a 17% difference. Vertical hard tissue gain averaged 4.06 mm ± 0.56 mm and 3.55 mm ± 0.43 mm in case of submerged and open healing, respectively. Difference in this regard was 14% between the two groups. Horizontal ridge width at 9-month follow-up was 5.89 mm ± 0.51 mm and 5.61 mm ± 1.21 mm with and without a membrane exposure respectively, resulting in a 5% difference.

Conclusions

With the help of the currently reported 3D radiographic evaluation method, it can be concluded that exposure of the new-generation d-PTFE membrane had less negative impact on clinical results compared to literature data reporting on expanded polytetrafluoroethylene membranes.

Resorbable Membrane Pouch Technique for Single-Implant Placement in the Esthetic Zone: A Preliminary Technical Case Report

The conventional protocol for lateral guided bone regeneration (GBR) in esthetic areas requires the securing of resorbable collagen membranes using titanium cortical bone pins to immobilize bone grafts. These procedures are highly invasive and can increase patient morbidity and discomfort. Herein, we introduce a minimally invasive novel resorbable membrane pouch technique, wherein collagen membranes can be immobilized by securing them to the periosteum without the need of titanium pins. We describe 11 cases of single-immediate- or delayed-implant placement in the atrophic maxilla esthetic zone. All implants were successful and functional without pain or inflammation and with optimal soft-tissue health and esthetics. Radiographic evaluation with cone-beam computed tomography (CBCT) and esthetic assessment using the pink esthetic score (PES) were performed. At the time of implant placement, the average augmented bone width was 2.8 ± 0.6 mm on CBCT analysis. In all cases, resorption of the augmented bone was confirmed with an average of −1.3 ± 0.8 mm. Soft-tissue outcomes were scored 1 year after permanent restoration. The PES score 1 year after treatment was 11.9 ± 1.4. The resorbable membrane pouch technique with immediate or delayed implant placement for buccal dehiscence in the esthetic area can be predictable and is minimally invasive.

Latest Findings of the Regenerative Materials Application in Periodontal and Peri-Implant Surgery: A Scoping Review

Regenerative dentistry represents a therapeutic modern approach involving biomaterials and biologics such as mesenchymal stem cells. The role of regenerative dentistry is promising in all branches of dentistry, especially in periodontology and implantology for the treatment of bony defects around teeth and implants, respectively. Due to the number of different materials that can be used for this purpose, the aim of the present review is to evidence the regenerative properties of different materials both in periodontitis and peri-implantitis as well as to compare their efficacy. Clinical trials, case-control studies, cross-sectional studies, and cohort studies have been considered in this review. The outcome assessed is represented by the regenerative properties of bone grafts, barrier membranes, and biological materials in the treatment of intrabony and furcation defects, peri-implantitis sites, alveolar ridge preservation, and implant site development. Based on the studies included, it can be stated that in the last years regenerative materials in periodontal and peri-implant defects treatments have shown excellent results, thus providing valuable support to surgical therapy. To achieve optimal and predictable results, clinicians should always consider factors like occlusal load control, prevention of microbial contamination, and wound dehiscence. Further evidence is required about the use of enamel matrix derivative in alveolar ridge preservation, as well as of stem cells and bone morphogenetic proteins-2 in furcation defects and peri-implantitis sites. Considering the high amount of research being conducted in this field, further evidence is expected to be obtained soon.

Biomaterials for Periodontal Regeneration

As a widespread chronical disease, periodontitis progressively destroys tooth-supporting structures (periodontium) and eventually leads to tooth loss. Therefore, regeneration of damaged/lost periodontal tissues has been a major subject in periodontal research. During periodontal tissue regeneration, biomaterials play pivotal roles in improving the outcome of the periodontal therapy. With the advancement of biomaterial science and engineering in recent years, new biomimetic materials and scaffolding fabrication technologies have been proposed for periodontal tissue regeneration. This article summarizes recent progress in periodontal tissue regeneration from a biomaterial perspective. First, various guide tissue regeneration/guide bone regeneration membranes and grafting biomaterials for periodontal tissue regeneration are overviewed. Next, the recent development of multifunctional scaffolding biomaterials for alveolar bone/periodontal ligament/cementum regeneration is summarized. Finally, clinical care points and perspectives on the use of biomimetic scaffolding materials to reconstruct the hierarchical periodontal tissues are provided.

Horizontal augmentation techniques in the mandible: a systematic review

Purpose

Placement of dental implants has evolved to be an advantageous treatment option for rehabilitation of the fully or partially edentulous mandible. In case of extensive horizontal bone resorption, the bone volume needs to be augmented prior to or during implant placement in order to obtain dental rehabilitation and maximize implant survival and success.

Methods

Our aim was to systematically review the available data on lateral augmentation techniques in the horizontally compromised mandible considering all grafting protocols using xenogeneic, synthetic, or allogeneic material. A computerized and manual literature search was performed for clinical studies (published January 1995 to March 2021).

Results

Eight studies ultimately met the inclusion criteria comprising a total of 276 procedures of xenogeneic, allogeneic, or autogenous bone graft applications in horizontal ridge defects. Particulate materials as well as bone blocks were used as grafts with a mean follow-up of 26.0 months across all included studies. Outcome measures, approaches and materials varied from study to study. A gain of horizontal bone width of the mandible with a mean of 4.8 mm was observed in seven of eight studies. All but one study, reported low bone graft failure rates of 4.4% in average.

Conclusions

Only limited data are available on the impact of different horizontal augmentation strategies in the mandible. The results show outcomes for xenogeneic as well as autologous bone materials for horizontal ridge augmentation of the lower jaw. The use of allogeneic bone-block grafts in combination with resorbable barrier membranes must be re-evaluated. Randomized controlled clinical trials are largely missing.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40729-022-00421-7.

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.

Alveolar Bone Ridge Augmentation Using Polymeric Membranes: A Systematic Review and Meta-Analysis

Alveolar bone ridge resorption occurred after natural teeth loss and it can restrict the possibility of dental implants placement. The use of bone regenerative procedures is frequently required. The existing evidence regarding the efficacy of horizontal bone ridge augmentation trough guided bone regeneration (GBR) using polymeric membranes was stated. A systematic review and meta-analysis were performed. Electronic and manual literature searches were conducted. Screening process was done using the National Library of Medicine (MEDLINE by PubMed), Embase, and the Cochrane Oral Health. Included articles were randomized controlled trials and observational studies. Weighted means were calculated. Heterogeneity was determined using Higgins (I2). If I2 > 50% a random-effects model was applied. It was found that the mean of horizontal bone gain was 3.95 mm, ranging from 3.19 to 4.70 mm (confidence interval 95%). Heterogeneity is I2 = 99% (confidence interval 95%) and significance of the random-effects model was p < 0.001. The complications rate was 8.4% and membrane exposure was the most frequent. Through this study, we were able to conclude that the existing scientific evidence suggests that GBR using polymeric membranes is a predictable technique for achieving horizontal bone augmentation, thus, permitting a proper further implant placement.