Guided Bone Regeneration Research Articles

Profilometric, esthetic, and patient-reported outcomes of the L-shape technique combined with delayed connective tissue grafting in the maxillary anterior region: A 3-year case series study.

To evaluate the profilometric, esthetic, and patient-reported outcomes of peri-implant tissues in the maxillary anterior esthetic zone following guided bone regeneration (GBR) using the L-shape technique combined with delayed connective tissue grafting (CTG). Profilometric and pink esthetic score (PES) measurements were performed at the time of implant surgery with GBR (T0) and at the 1- (T1), 2- (T2), and 3-year (T3) follow-up. Patient-reported outcomes were also assessed using the Oral Health Impact Profile-14 (OHIP-14) questionnaire. Statistical analysis over 3 years of follow-up assessed changes at time points (T0, T1, T2, and T3) and time periods (T0-T1, T0-T2, and T0-T3) using the Wilcoxon signed-rank test. A total of 12 patients (57.5 ± 12.3 years) were included in this study. The mean profilometric change in peri-implant tissues over the 3-year follow-up period was 3.49 ± 1.11 mm, and the buccal contours were not significantly different between the comparison periods. The PES remained stable, while all OHIP-14 domain scores improved significantly. Simultaneous implant placement and GBR using the L-shape technique combined with delayed CTG in the maxillary anterior region provides stable buccal profiles and consistent esthetics and improves patient-reported quality of life over a 3-year period. This study demonstrated that GBR using the L-shape technique combined with delayed CTG in the maxillary anterior region improved the buccal profile, esthetics, and patient-reported quality of life.

Development of antibacterial collagen membranes with optimal silver nanoparticle content for periodontal regeneration

The effective control of pathogenic bacteria is crucial in the restoration of periodontal tissue affected by periodontitis. Guided tissue regeneration (GTR) membranes are commonly used to aid in the repair of periodontal defects. Therefore, there is a clear advantage in developing antibacterial periodontal membranes that can effectively eliminate infections and promote tissue regeneration. This study aimed to create a collagen membrane with optimal content of silver nanoparticles (AgNPs) for effective antibacterial properties and minimal toxicity to mammalian cells. Ascorbic acid-reduced AgNPs were incorporated into collagen at the ratio of 0.5%, 1%, 2%, and 3% (based on total dry weight). Collagen/AgNPs hydrogels were compressed and freeze-dried to form membranes and then were characterized. Antibacterial activity was tested against Fusobacterium nucleatum and Enterococcus faecalis, and membrane cytocompatibility was accomplished on human gingival fibroblasts. Membranes with 2% and 3% AgNPs exhibited significant antibacterial activity, while 1% showed minimal activity and 0.5% and 0% showed none. HGF cells on the 3% AgNPs membrane had poor viability, proliferation, and adhesion, but 0%, 0.5%, 1%, and 2% AgNPs membranes showed desirable cellular behavior. In conclusion, the collagen membrane with 2% AgNPs demonstrated both antibacterial capacity and excellent cytocompatibility, making it a promising choice for periodontal treatments, especially in GTR approaches.

Results of bone grafting using a xenogenic cortical plate BiOTECK

BACKGROUND: The fundamental condition that determines the effectiveness of treatment, with immediate and long-term positive results, is the amount of bone tissue in the jaws at the proposed implantation site. Defects in the dentition to a large extent and severe atrophy of the bone tissue of the jaws due to the loss of teeth significantly limit the use of dental implantation. It is reasonable to expand the indications for the use of dental implants in cases of atrophy of the jaw bone tissue in the installation site. This allows the optimization of surgical techniques aimed at increasing the volume of the jaw bone tissue, such as the use of new osteoplastic materials for guided bone regeneration.
 AIM: This study aimed to analyze the results of a jawbone graft using a BiOTECK xenogeneic cortical plate.
 MATERIALS AND METHODS: The test group consisted of 22 patients (11 men and 11 women) with jawbone atrophy. All patients underwent bone graft surgery using a BiOTECK xenogeneic cortical plate (BiOTECK, Italy).
 In the course of the study, all patients with jawbone loss underwent a dynamic clinical and X-ray examination during the following stages: during the dental implant surgery planning stage aimed at determining the volume of the bone tissue available and identifying the associated conditions and diseases (prior to conducting an osteoplastic procedure), prior to dental implant installation (6 months after osteoplastic surgery), and prior to the start of the orthopedic stage of treatment (12 months after osteoplastic surgery).
 RESULTS: The cone beam computed tomography data were analyzed and statistically processed to obtain the results. It was revealed that the values of the “bone densitometry” indicator increased 6 months after the bone graft using the BiOTECK xenogeneic cortical plate, and the values of the “densitometric density of jaw bone tissue” indicator increased.
 Immediately after bone grafting using the BiOTECK xenogeneic cortical plate, the thickness of the bone tissue of the upper jaw increased by an average of 5.0±0.1 mm and that of the lower jaw increased by an average of 3.9±0.1 mm. In the first stage of the dental implant surgery (6 months after osteoplastic procedure), due to resorption, the thickness of the bone tissue of the alveolar process of the upper jaw decreased by 1.1±0.1 mm and amounted to 6.8±0.1 mm (bone resorption rate: 13.9%), and the thickness of the bone tissue of the alveolar process of the lower jaw decreased by 0.8±0.2 mm and amounted to 6.6±0.3 mm (bone resorption rate: 10.3%).
 CONCLUSION: The clinical and X-ray results obtained 1 year after installing dental implants and performing bone graft surgery using the BiOTECK xenogeneic cortical plate indicate a stable volume of marginal bone tissue in the area of alveolar crest reconstruction.

Zinc hybrid polyester barrier membrane accelerates guided tissue regeneration

Barrier membranes play a pivotal role in the success of guided periodontal tissue regeneration. The biodegradable barriers predominantly used in clinical practice often lack sufficient barrier strength, antibacterial properties, and bioactivity, frequently leading to suboptimal regeneration outcomes. Although with advantages in mechanical strength, biodegradability and plasticity, bioinert aliphatic polyesters as barrier materials are usually polymerized via toxic catalysts, hard to be functionalized and lack of antibacterial properties. To address these challenges, we propose a new concept that controlled release of bioactive substance on the whole degradation course can give a bioinert aliphatic polyester bioactivity. Thus, a Zn-based catalytic system for polycondensation of dicarboxylic acids and diols is created to prepare zinc covalent hybrid polyester (PBS/ZnO). The atomically-dispersed Zn2+ ions entering main chain of polyester molecules endow PBS/ZnO barrier with antibacterial properties, barrier strength, excellent biocompatibility and histocompatibility. Further studies reveal that relying on long-term controlled release of Zn2+ ions, the PBS/ZnO membrane greatly expedites osteogenetic effect in guided tissue regeneration (GTR) by enhancing the mitochondrial function of macrophages to induce M2 polarization. These findings show a novel preparation strategy of bioactive polyester biomaterials based on long term controlled release of bioactive substance that integrates catalysis, material structures and function customization.

Fabrication and characterization of a multi-functional GBR membrane of gelatin-chitosan for osteogenesis and angiogenesis

Guided bone regeneration (GBR) membranes are widely used to treat bone defects. In this study, sequential electrospinning and electrospraying techniques were used to prepare a dual-layer GBR membrane composed of gelatin (Gel) and chitosan (CS) containing simvastatin (Sim)-loaded poly(lactic-co-glycolic acid) (PLGA) microspheres (Sim@PLGA/Gel-CS). As a GBR membrane, Sim@PLGA/Gel-CS could act as a barrier to prevent soft tissue from occupying regions of bone tissue. Furthermore, compared with traditional GBR membranes, Sim@PLGA/Gel-CS played an active role on stimulating osteogenesis and angiogenesis. Determination of the physical, chemical, and biological properties of Sim@PLGA/Gel-CS membranes revealed uniform sizes of the nanofibers and microspheres and appropriate morphologies. Fourier-transform infrared spectroscopy was used to characterize the interactions between Sim@PLGA/Gel-CS molecules and the increase in the number of amide groups in crosslinked membranes. The thermal stability and tensile strength of the membranes increased after N-(3-dimethylaminopropyl)-N9- ethylcarbodiimide/N-hydroxysuccinimide crosslinking. The increased fiber density of the barrier layer decreased fibroblast migration compared with that in the osteogenic layer. Osteogenic function was indicated by the increased alkaline phosphatase activity, calcium deposition, and neovascularization. In conclusion, the multifunctional effects of Sim@PLGA/Gel-CS on the barrier and bone microenvironment were achieved via its dual-layer structure and simvastatin coating. Sim@PLGA/Gel-CS has potential applications in bone tissue regeneration.

Attachment Loss Attributable to Third Molar Malposition/Extraction: The Case for Classification

Background: The 2017 World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions established a periodontitis staging and grading scheme that—for the first time—integrates an assessment of disease severity with an appraisal of therapeutic complexity and risk for disease progression. Individuals exhibiting attachment loss attributable to third molar malposition or extraction represent a large cohort of non-periodontitis patients highly likely to respond favorably to treatment. The purpose of this clinical report is to illustrate the value in formally categorizing this common periodontal condition. Case Description: Two male patients were referred to the Department of Periodontics, Army Postgraduate Dental School, for evaluation of bone and attachment loss limited to distal surfaces of mandibular second molars. Each patient was treated using a combination of guided tissue regeneration and bone replacement grafts. Favorable clinical and radiographic outcomes were observed over follow-up periods ranging from 4 months to 4 years. Practical Implications: Many patients experiencing bone and attachment loss attributable to third molar malposition or extraction lack periodontitis risk factors/indicators, have low susceptibility to the disease, and are highly likely to respond favorably to treatment. Future classification systems of periodontal diseases and conditions should formally categorize this commonly encountered periodontal condition.

Three-Dimensional-Printed Spherical Hollow Structural Scaffolds for Guiding Critical-Sized Bone Regeneration.

The treatment of bone tissue defects continues to be a complex medical issue. Recently, three-dimensional (3D)-printed scaffold technology for bone tissue engineering (BTE) has emerged as an important therapeutic approach for bone defect repair. Despite the potential of BTE scaffolds to contribute to long-term bone reconstruction, there are certain challenges associated with it including the impediment of bone growth within the scaffolds and vascular infiltration. These difficulties can be resolved by using scaffold structural modification strategies that can effectively guide bone regeneration. This study involved the preparation of biphasic calcium phosphate spherical hollow structural scaffolds (SHSS) with varying pore sizes using 3D printing (photopolymerized via digital light processing). The chemical compositions, microscopic morphologies, mechanical properties, biocompatibilities, osteogenic properties, and impact on repairing critical-sized bone defects of SHSS were assessed through characterization analyses, in vitro cytological assays, and in vivo biological experiments. The results revealed the biomimetic properties of SHSS and their favorable biocompatibility. The scaffolds stimulated cell adhesion, proliferation, differentiation, and migration and facilitated the expression of osteogenic genes and proteins, including Col-1, OCN, and OPN. Furthermore, they could effectively repair a critical-sized bone defect in a rabbit femoral condyle by establishing an osteogenic platform and guiding bone regeneration in the defect region. This innovative strategy presents a novel therapeutic approach for assessing critical-sized bone defects.

Assessment of bone regeneration after maxillary radicular cyst enucleation with or without bone grafting materials: a retrospective cohort study

ObjectiveThe limitations of spontaneous bone healing underscore the necessity for exploring alternative strategies to enhance bone regeneration in maxillary radicular cyst cases. This retrospective study aimed to assess the impact of a bone substitute material (i.e., Bio-Oss) on bone volume regeneration following maxillary radicular cyst enucleation using cone-beam computed tomography (CBCT).Materials and methodsSeventy-three patients with maxillary radicular cysts were divided into two groups: one undergoing guided bone regeneration (GBR) with Bio-Oss and absorbable collagen membrane (n = 35), and the other receiving cyst excision alone (n = 38). Volumetric measurements using Amira software on CBCT scans evaluated bone regeneration, with cystic lesion shrinkage rates calculated. Intergroup comparisons utilized independent sample t-tests (P < 0.05), and linear regression analysis assessed the influence of preoperative cyst volume and group on bone healing.ResultsBoth groups showed similar success rates in bone formation at the 12-month follow-up, with no significant differences between them (mean (SD), control: 75.16 (19.17) vs. GBR: 82 (20.22), P > 0.05). Linear regression analysis revealed a negative correlation between preoperative cyst volume and bone regeneration in both groups (P < 0.05).ConclusionBio-Oss may not significantly enhance bone augmentation in maxillary radicular cysts. In addition, preoperative cyst volume negatively affected the shrinkage rate of cystic lesions.Clinical relevanceClinicians should consider patient-specific factors such as anatomy and lesion size when determining the need for bone substitute materials. Future research could focus on optimizing treatment protocols and alternative regenerative strategies to improve patient outcomes in maxillary cyst cases.

Evaluation of Regenerative Efficacy of Amnion and Chorion Membrane in Treatment of Mandibular Molar Furcation Defects: A Clinico-radiographic Study.

Amnion and chorion membranes possess unique inherited biological properties that enhance wound healing and may accelerate periodontal regeneration. The present study aims to evaluate and compare the efficacy of amnion and chorion membranes in the treatment of furcation defects. A total of 20 patients were selected and were randomly allocated to group I and group II with 10 subjects in each group. Amnion and chorion membranes are placental-derived membranes that accelerate regeneration by having natural growth factors with their antimicrobial and inflammation reduction properties. Group I was treated using bone grafting with decalcified freeze-dried bone allograft (DFDBA) and placement of amnion as a membrane for guided tissue regeneration (GTR) whereas group II was treated using bone grafting with DFDBA and placement of chorion as a membrane for GTR. The patients were followed for clinical and radiographic parameters and were evaluated between 3 and 6 months after surgery. In intragroup comparison, a significant difference was evident in both the groups for all the clinical and radiographic parameters within the groups. (p = 0.01) This means both amnion and chorion membranes showed statistically significant regenerative efficacy. In intergroup comparison, the results show that all the clinical parameters and radiographic parameters show no significant difference between the groups. The amnion and chorion membranes had similar regenerative efficacy in combination with DFDBA in patients with buccal degree II furcation defects in mandibular molars. The amnion and chorion membranes have shown significant improvement in clinical and radiographic parameters when used for the treatment of buccal degree II furcation defects in mandibular molars. How to cite this article: Mallapragda S, Gupta R, Gupta S, et al. Evaluation of Regenerative Efficacy of Amnion and Chorion Membrane in Treatment of Mandibular Molar Furcation Defects: A Clinico-radiographic Study. J Contemp Dent Pract 2024;25(2):160-167.

Survival analysis of dental implants placed in horizontally severely resorbed maxillae after reconstruction with xenogeneic graft: a case series.

To evaluate the survival rates of dental implants with a hybrid macrostructure and the surface biomimetically coated with nanohydroxyapatite, placed in horizontally atrophic maxillae previously submitted to the guided bone regeneration (GBR) procedure, associated with the use of a deproteinized bovine bone graft (DBB). Twenty-five patients who received 196 implants were involved in this study. First, these patients were submitted to GBR procedures and maxillary sinus lift, where DBB was used as the grafting material. The dental implants were placed after a minimum period of 6 months of the grafting procedures. The patients were followed up every six months and clinical/radiographic examinations were performed to assess the implants, using the following indicators as a reference: (1) Absence of mobility; (2) Absence of pain. Data about the age, surgery time, smoking status, implant size, and time between the grafting procedure and implant placement were correlated with implant failures. Twelve implants failed, generating a survival rate of 94.23%. None of the variables analysed correlated with the implant failures. Implants with a hybrid macrostructure and surface biomimetically coated with nanohydroxyapatite present good survival rates in horizontally atrophic maxillae grafted with DBB.

Immediate Loaded Post Extraction Implant and Connective Graft-Guided Bone Regeneration: A Case Report

This case report describes the clinical and therapeutic approach used in a 32-year-old female patient with a tooth fracture in tooth 22. The patient, with no history of systemic disease, presented with a chronic periapical lesion and a cervical fracture in the affected tooth. Treatment included atraumatic extraction of the tooth, followed by placement of a 3.75 x 10mm post-extraction implant with immediate loading and guided bone regeneration. The minimally invasive surgical technique was employed using the Dentoflex® drilling sequence. The primary stability of the implant, measured in 37 Newtons of torque, allowed the placement of a prefabricated metal abutment for the subsequent cemented crown. Bone regeneration of the interimplant space was successfully performed, supplemented by connective grafting due to the patient's thin gingival phenotype. Postoperative follow-up, including controls at 7, 14 days and four months, showed a satisfactory conformation of the gingival margin and papillary tissue, consolidating the success of the treatment.

Guided bone regeneration for peri-implant augmentation: Aretrospective study comparing two surgical techniques with a mean follow-up of 26 months.

To introduce a modified guided bone regeneration (GBR) technique using intact periosteum and deproteinized bovine bone mineral (DBBM) for peri-implant augmentation and compare the clinical outcomes with those of conventional GBR. Patients who received peri-implant augmentation in posterior sites between 2015 and 2021 were reviewed in this study. Group A was treated with a modified GBR technique, and Group B was treated with conventional GBR. For group comparison, propensity score matching was performed with a sensitivity analysis. The implant survival rate, dimensional changes in hard tissue, marginal bone loss (MBL), and peri-implant parameters were evaluated. In total, 114 implants from 98 patients were included. The implant survival rates were 95.74% in Group A and 95.00% in Group B during the follow-up period. At 6 months, the median horizontal thickness was recorded at 0.87 mm (IQ1-IQ3 = 0.00-1.75 mm) in Group A, exhibiting a relatively lower value compared to the corresponding measurement of 0.98 mm (IQ1-IQ3 = 0.00-1.89 mm) in Group B (p = .937). Vertical height displayed no statistically significant intergroup difference between the two groups (p = .758). The mean follow-up period was 25.83 ± 12.93 months after loading in Group A and 27.47 ± 21.29 months in Group B (p = .761). MBL and peri-implant parameters were comparable between the two groups. Within the limitations of this study, the modified GBR technique using intact periosteum and DBBM grafting might be a viable alternative to correct bone defects around implants in molar and premolar sites.

Strontium-zinc-based phosphate coatings fabricated in situ on the zinc-pretreated magnesium alloy for degradation control and cytocompatibility enhancement

Owing to the good mechanical support, degradability, and biocompatibility, magnesium (Mg) alloys have large potential in medical applications such as guided bone regeneration membranes. However, the rapid degradation of Mg alloys under physiological conditions hinders many clinical applications. Herein, strontium-zinc-based phosphate (SZP) coatings are fabricated in situ on the zinc (Zn)-electrodeposited WE43 Mg alloy for corrosion protection, degradation control, and cytocompatibility enhancement. The Zn coating acts as a protective cathode for the Mg alloy substrate and provides a stable environment to foster the growth of the SZP coating in comparison with direct deposition onto the Mg alloy surface. The virtues are verified by the smaller corrosion current density, corrosion of the Zn coating instead of the Mg alloy substrate after soaking in artificial saliva, as well as good adhesion provided by the Zn-incorporated transition layer of SrZn2(PO4)2 between the Zn coating and SZP coating. The dense and inert SZP coating mitigates degradation as shown by a decrease in the corrosion current density of 44 times to 0.21 uA cm−2 in the simulated oral environment with artificial saliva. Furthermore, the coating resistance and charge transfer resistance increase by more than one order of magnitude compared to the Zn-treated Mg alloy, and there is no obvious degradation after immersion for 7 days. The Zn coating shows adverse effects on the attachment, spreading, and proliferation of MC3T33-E1 pre-osteoblasts, but the SZP coating providing a higher level larger than 100% of the cell viability after incubation with its extract for 3 days is more compatible with cells because of the retarded dissolution and bio-friendly chemical compositions of SrHPO4 and SrZn2(PO4)2. The hybrid coating has excellent prospects in biomedical products such as biodegradable Mg-based guided bone regeneration membranes.

Utilising blood-derived products for guided tissue regeneration in periradicular surgery: a systematic review and meta-analysis

Background Since 1982, guided tissue regeneration (GTR) has become increasingly popular. The recent progress in GTR research focuses on the application of blood-derived products. However, no comprehensive systematic review has been conducted to assess its effectiveness specifically in periradicular surgery. Therefore, the aim of this review was to analyse the outcomes of periradicular with GTR using blood-derived products compared to standard periradicular surgery. Methods This review was based on randomised controlled trials comparing periradicular surgery in conjunction with GTR with blood-derived products and the standard periapical surgery. The databases searched included Embase, MEDLINE, Cochrane CENTRAL, and Dentistry and Oral Sciences Source, with the most recent search conducted on December 16th, 2022. Additionally, reference lists of similar systematic reviews were examined, while international trials registries and repositories were consulted for unpublished studies. Two blinded independent reviewers carried out the screening and the included studies underwent critical appraisal. The findings are reported in accordance with the PRISMA guidelines. Results A total of 261 publications were initially reviewed based on their title and abstract, resulting in seventeen studies that underwent full-text screening. At this stage, 14 studies were excluded, leaving three randomised controlled trials to be included. These trials involved a total of 85 patients. A meta-analysis was conducted for the outcome of healing. The overall treatment effect was 0.78 (95% CI 0.18 to 3.34), indicating a preference towards the control group. Conclusion Based on a meta-analysis of three studies, there was no statistically significant distinction observed in terms of healing between the GTR involving blood-derived products and standard procedure groups. However, critical appraisal revealed indirectness and imprecision, resulting in a certainty rating of 'low'. Thus, additional robust evidence is necessary to support the utilisation of blood-derived products in GTR techniques to enhance periradicular surgery outcomes. Systematic review registration number PROSPERO CRD42020222663.

Anti-Wound Dehiscence and Antibacterial Dressing with Highly Efficient Self-Healing Feature for Guided Bone Regeneration Wound Closure.

Guided bone regeneration (GBR) is a well-established technique for preserving and enhancing alveolar ridge structures. Success in GBR relies on fulfilling the Primary wound closure, Angiogenesis, Space maintenance, and Stability (PASS) principles. Conventional methods, involving titanium meshes and sutures, have drawbacks, including the need for secondary removal and customization challenges. To address these issues, an innovative multifunctional GBR dressing (MGD) based on self-healing elastomer (PUIDS) is introduced. MGD provides sutureless wound closure, prevents food particle accumulation, and maintains a stable environment for bone growth. It offers biocompatibility, bactericidal properties, and effectiveness in an oral GBR model. In summary, MGD provides a reliable, stable osteogenic environment for GBR, aligning with PASS principles and promoting superior post-surgery bone regeneration.

Clinical benefits of autologous platelet concentrate in periodontal intrabony defects: A network meta-analysis of randomized controlled trials.

This study aimed to compare clinical benefits of autologous platelet concentrate with other periodontal regenerative approaches in intrabony defects. An electronic and hand search of studies up to December 2022 was conducted. Randomized controlled trials with at least 6 months of follow-up were identified to compare autologous platelet concentrates with enamel matrix derivative, bone graft, guided tissue regeneration, and open-flap debridement. All approaches involved papilla preservation flap surgery. The outcomes included probing depth reduction, clinical attachment level gain, linear bone fill, and safety. A network meta-analysis and meta-regression were performed. Fifty-seven studies were included in five network meta-analyses. Autologous platelets concentrate and its adjunct treatments achieved significantly greater clinical and radiographic parameters than did open-flap debridement, and had comparable or better performance than other regenerative treatments. Platelet-rich fibrin showed superiority over platelet-rich plasma in probing depth reduction at 6-month follow-up. Minimal pain and improved wound healing were observed in the treatments with autologous platelet concentrate. Meta-regression showed that deeper baseline intrabony defects resulted in larger probing depth reductions, while smoking impaired the effectiveness of regenerative surgeries. Minimal invasive flap designs led to less effect of regenerative materials. Autologous platelet concentrate is a promising biomaterial in periodontal regeneration due to its convenience, safety, and biocompatibility characteristics.

Lysophosphatidic Acid/Polydopamine-Modified nHA Composite Scaffolds for Enhanced Osteogenesis via Upregulating the Wnt/Beta-Catenin Pathway.

Guided bone regeneration (GBR) technology has been widely used for the regeneration of periodontal bone defects. However, the limited mechanical properties and bone regeneration potential of the currently available GBR membranes often limit their repair effectiveness. In this paper, serum-derived growth factor lysophosphatidic acid (LPA) nanoparticles and dopamine-decorative nanohydroxyapatite (pDA/nHA) particles were double-loaded into polylactic-glycolic acid/polycaprolactone (PLGA/PCL) scaffolds as an organic/inorganic biphase delivery system, namely, PP-pDA/nHA-LPA scaffolds. Physicochemical properties and osteogenic ability in vitro and in vivo were performed. Scanning electron microscopy and mechanical tests showed that the PP-pDA/nHA-LPA scaffolds had a 3D bionic scaffold structure with improved mechanical properties. In vitro cell experiments demonstrated that the PP-pDA/nHA-LPA scaffolds could significantly enhance the attachment, proliferation, osteogenic differentiation, and mineralization of MC3T3-E1 cells. In vivo, the PP-pDA/nHA-LPA scaffolds exhibited great cytocompatibility and cell recruitment ability in 2- and 4-week subcutaneous implantation experiments and significantly promoted bone regeneration in the periodontal defect scaffold implantation experiment. Moreover, LPA-loaded scaffolds were confirmed to enhance osteogenic activities by upregulating the expression of β-catenin and further activating the Wnt/β-catenin pathway. These results demonstrate that the biphase PP-pDA/nHA-LPA delivery system is a promising material for the GBR.

Recent Advances in Scaffolds for Guided Bone Regeneration.

The rehabilitation of alveolar bone defects of moderate to severe size is often challenging. Currently, the therapeutic approaches used include, among others, the guided bone regeneration technique combined with various bone grafts. Although these techniques are widely applied, several limitations and complications have been reported such as morbidity, suboptimal graft/membrane resorption rate, low structural integrity, and dimensional stability. Thus, the development of biomimetic scaffolds with tailor-made characteristics that can modulate cell and tissue interaction may be a promising tool. This article presents a critical consideration in scaffold's design and development while also providing information on various fabrication methods of these nanosystems. Their utilization as delivery systems will also be mentioned.

Bilayer Technique for Alveolar Ridge Augmentation in Pre-Prosthetic Implant Surgery: Indications and Problems

Abstract Background: Prosthetic rehabilitation of missing teeth with dental implant-supported restorations has recently become a predictable treatment option in contemporary dentistry with a highly successful rate. Due to different factors, vertical and horizontal bone loss could present, and the available alveolar bone may not be sufficient for optimum implant position. Ridge augmentation procedures could be applied to increase the volume of the deficient sites for accurate prosthetic implant placement, which assures functional and esthetic stability of tissues around the implants, essential for long-term success. Our study aims to evaluate the efficiency of the bilayer technique of guided bone regeneration for alveolar ridge augmentation procedure in cases of bone deficiency for optimum implant placement and long-term success. Materials and methods: We present several cases of alveolar bone deficiency treated with the bilayer technique – the combination of allo- and xenograft, covered by collagen membrane, with long-term follow-up. The defects were filled with allograft, and a layer of xenograft and barrier membrane was placed above it. This technique combines the benefits of all xenografts and barrier membranes. Results: The bilayer technique with allo- and xenograft and collagen membranes is predictable, with a high success rate and lower morbidity. We have a 100% survival rate of the implants placed in a grafted area with long-term follow-up with excellent aesthetic and functional results. Conclusions: The bilayer technique uses the benefits of two bone graft materials, is associated with less morbidity for the patients, and has excellent long-term results if performed accurately according to indications and technique.

Leaf‐Mimicking Superstructured Porous Membrane with Multiple Bioactive Pro‐Healing Functions for Effective Guided Bone Regeneration

AbstractBarrier membrane, a key material for guided bone regeneration surgery, is applied between soft and hard tissue interfaces in complex oral environment. The abilities to integrate contradictory requirements and self‐regulate the local microenvironment are highly desirable for barrier membrane but remain challenging to achieve. Herein, inspired by the leaf's hierarchical multifunctional synergy, a kind of superstructured porous membrane (SPM), integrating asymmetric surface pores, interconnected macropores and functional micropores, is developed based on the combination of breath figure and phase separation. For the SPM, the densely porous layer can inhibit penetration of soft tissue cells and maintain osteogenic space, and the loosely porous layer with interconnected microporous channels can effectively promote the adhesion and proliferation of osteoblasts, help to transport nutrients, and expose functional components. Meanwhile, porous carbon nanospheres introduced into SPM as multifunctional core components can ameliorate the undesirable microenvironment by scavenging reactive oxygen species, repairing bioelectrical environment, and killing bacteria, thus achieving multiple bioactive pro‐healing functions for efficient bone regeneration in vivo. These findings can open an appealing avenue for developing high‐performance barrier membranes as well as many other implant materials.