Comparing the Clinical and Radiographic Outcomes of Two Different Surgical Approaches for Treating Infrabony Defects in Chronic Periodontitis Patients.

Background: Chronic periodontitis is a prevalent oral health issue, affecting a substantial portion of the population. Infrabony defects, characterized by bone loss around teeth, are a hallmark of this condition and require surgical intervention to prevent further damage and tooth loss. Two commonly used surgical approaches are open flap debridement (OFD) and guided tissue regeneration (GTR). Materials and Methods: This prospective cohort study included 60 patients with chronic periodontitis and infrabony defects. Patients were randomly assigned to either the OFD or GTR group. Clinical parameters, including probing depth (PD) and clinical attachment level (CAL), were recorded at baseline and at 6-month and 12-month follow-up appointments. Radiographic assessments were conducted using periapical radiographs. The primary outcome measures were changes in PD and CAL, while secondary outcomes included radiographic evidence of bone regeneration. Results: At the 6-month follow-up, the OFD group demonstrated an average reduction in PD of 2.4 mm (SD = 0.8) and an increase in CAL of 1.6 mm (SD = 0.5). In contrast, the GTR group showed a reduction in PD of 2.1 mm (SD = 0.7) and an increase in CAL of 1.9 mm (SD = 0.6). These differences were not statistically significant (P > 0.05). Radiographic analysis indicated a mean bone fill of 1.2 mm (SD = 0.4) in the OFD group and 1.4 mm (SD = 0.3) in the GTR group at 12 months, with no significant difference observed between the two groups (P > 0.05). Conclusion: In this study, both OFD and GTR approaches demonstrated comparable clinical and radiographic outcomes in the treatment of infrabony defects in chronic periodontitis patients.

The use of guided tissue regeneration in endodontic Microsurgery: Setting a threshold.

Aim: We aimed to compare the radiographic outcomes of conventional and regenerative approaches in endodontic microsurgery (EMS) and set a critical defect size for healing in conventional and regenerative therapies. Methodology: The study evaluated 53 root canal-treated teeth (33 patients) with periapical lesions. Among them, 19 teeth (35.8 %) were treated with regenerative treatment, whereas 34 teeth (64.1 %) were managed with the conventional approach. Conventional and regenerative approaches were performed by endodontic and periodontic residents under consultants' supervision. Healing was evaluated after a minimum period of 6 months by comparing pre- and post-operative cone-beam computed tomography (CBCT) findings. The radiographic interpretation was conducted by a single examiner who was not participating in the surgeries and was blind on the type of treatment prior to CBCT evaluation. New healing criteria were proposed owing to the limitations on the present criteria in evaluating endodontic surgery after regenerative treatment. Critical measurements were calculated for each approach based on periapical lesion dimensions. Results: The regenerative approach presented significantly better healing than conventional treatment (mean, 1.21 and 1.59, respectively; p = 0.047). Based on the critical-point calculations, the conventional approach was effective in lesions of up to 3 mm depth and height, whereas the regenerative approach resulted in better healing rates in lesions with 3-9 mm depth and 3-6 mm height. Conclusions: Performing the regenerative approach in EMS resulted in better healing rates than those of the conventional approach. The conventional approach is recommended for small periapical lesions, whereas the first had better results in larger lesions.

The impact of bone grafting with/without barrier membrane placement on the outcome of apical surgery: A systematic review and meta-analysis.

BACKGROUND: Regenerative techniques are increasingly being advocated in endodontic apical surgery (AS) to enhance the healing of periapical lesions. Various grafting and membrane materials are employed as adjuncts to modern AS. OBJECTIVES: This systematic review aimed to answer the following PICO question: In patients with apical periodontitis (P) what is the impact of bone grafting with/without barrier membrane materials (I) compared with surgery without grafting materials (C) on the outcome of AS evaluated clinically and radiographically (O). METHODS: A systematic search was conducted in four databases (Embase, Web of Science, PubMed and Cochrane Central Register of Controlled Trials) until 1 August 2023. Google Scholar was also manually searched. Studies with a prospective randomized design were included. Cochrane risk-of-bias (RoB) tool 2.0 assessed bias. Two independent reviewers performed the study selection, data extraction and appraisal of studies. Meta-analysis was performed using R3.5.1 software. RESULTS: From the identified 2582 studies, eight randomized clinical trials were included for meta-analysis. Two studies had low RoB, while six had some concerns. Analysis revealed significantly better outcomes when surgery involved bone regeneration techniques than conventional surgery (OR = 2.18, 95% CI: 1.32-4.31, p = .004). Subgroup analyses on individual grafts (OR = 0.22, 95% CI: -0.99 to 1.44, p = .720) (OR = -0.09, 95% CI: -1.42 to 1.23, p = .885) and membranes (OR = -1.09, 95% CI: -2.94 to 0.76, p = .247) and their combinations (OR = 0.03, 95% CI: -1.50 to 1.55, p = .970) did not yield any significant results. The type of membrane used did not significantly impact the outcome (OR = -1.09, 95% CI: -2.94 to 0.76, p = .247) nor did altering the combination of graft/membrane. DISCUSSION: This systematic review examined the effects of bone grafting with/without membrane placement on the outcome of AS. It highlights the potential advantages of regenerative techniques and the need for further research in this area. CONCLUSIONS: Based on current evidence, bone grafting with/without barrier membrane placement significantly improves healing after AS. Subgroup analysis of resorbable membranes or grafting did not significantly influence the outcome. The combination of membrane and graft was also not significant. Future well-designed, randomized controlled trials in this area are essential before these materials can be recommended for routine use to enhance healing outcomes in AS. REGISTRATION: PROSPERO (CRD42021255171).

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.

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.

Preparation and optimization of an eggshell membrane-based biomaterial for GTR applications.

OBJECTIVES: Guided Tissue Regeneration (GTR) is a popular clinical procedure for periodontal tissue regeneration. However, its key component, the barrier membrane, is largely collagen-based and is still quite expensive, posing a financial burden to the patients as well as healthcare systems and negatively impacting the patient's decision-making. Thus, our aim is to prepare a novel biomimetic GTR membrane utilizing a natural biomaterial, soluble eggshell membrane protein (SEP), which is economical as it comes from an abundant industrial waste from food and poultry industries, unlike collagen. Additive polymer, poly (lactic-co-glycolic acid) (PLGA), and a bioceramic, nano-hydroxyapatite (HAp), were added to improve its mechanical and biological properties. METHODS: For this barrier membrane preparation, we initially screened the significant factors affecting its mechanical properties using Taguchi orthogonal array design and further optimized the significant factors using response surface methodology. Furthermore, this membrane was characterized using SEM, EDAX, and ATR-FTIR, and tested for proliferation activity of human periodontal ligament fibroblasts (HPLFs). RESULTS: Optimization using response surface methodology predicted that the maximal tensile strength of 3.1 MPa and modulus of 39.9 MPa could be obtained at membrane composition of 8.9 wt% PLGA, 7.2 wt% of SEP, and 2 wt% HAp. Optimized PLGA/SEP/HAp membrane specimens that were electrospun on a static collector showed higher proliferation activity of HPLFs compared to tissue culture polystyrene and a commercial collagen membrane. SIGNIFICANCE: From the results observed, we can conclude that SEP-based nanofibrous GTR membrane could be a promising, environment-friendly, and cost-effective alternative for commercial collagen-based GTR membrane products.

Application of mesenchymal stem/stromal cells in periodontal regeneration: Opportunities and challenges.

Guided tissue regeneration (GTR) has been widely used in the periodontal treatment of intrabony and furcation defects for nearly four decades. The treatment outcomes have shown effectiveness in reducing pocket depth, improving attachment gain and bone filling in periodontal tissue. Although applying GTR could reconstruct the periodontal tissue, the surgical indications are relatively narrow, and some complications and race ethic problems bring new challenges. Therefore, it is challenging to achieve a consensus concerning the clinical benefits of GTR. With the appearance of stem cell-based regenerative medicine, mesenchymal stem/stromal cells (MSCs) have been considered a promising cell resource for periodontal regeneration. In this review, we highlight preclinical and clinical periodontal regeneration using MSCs derived from distinct origins, including non-odontogenic and odontogenic tissues and induced pluripotent stem cells, and discuss the transplantation procedures, therapeutic mechanisms, and concerns to evaluate the effectiveness of MSCs.

Comparative evaluation of treatment of angular bone defect related to over-erupted tooth using guided tissue regeneration (GTR) followed by orthodontic intrusion (OI) versus OI followed by GTR: a controlled clinical trial.

BACKGROUND: Prematurity resulted from pathological migration of periodontally involved teeth with the loss of vertical stopping points between teeth, which can lead to teeth over eruption with dimensional changes favoring occlusal discrepancies. Therefore, evaluating and comparing the effect of guided tissue regeneration followed by orthodontic intrusion as opposed to orthodontic intrusion tracked by guided tissue regeneration in the treatment of an over-erupted tooth with angular bone loss. METHODS: Twenty teeth in ten cases were selected with at least two teeth with vertical over-eruption and angular bone loss with the presence of their opposing. In group one, ten teeth over-erupted were treated by guided tissue regeneration followed by orthodontic intrusion, whereas, in group two, ten teeth over-erupted were treated by orthodontic intrusion followed by guided tissue regeneration. They were evaluated clinically for pocket depth, bleeding on probing, and tooth mobility. Radiographical evaluation assessed by cone beam computed tomography. RESULTS: Clinically, there existed a statistically significant difference (P value ≤ 0.05) in favor of group one at six months post and in favor of group two at one year from re-evaluation regarding pocket depth and tooth mobility. Radiographically, in group one, there was a statistically significant improvement (P value ≤ 0.05) at six months post-guided tissue regeneration or orthodontic intrusion regarding defect depth and dimensional changes of the defect area, with a statistically significant difference (P value ≤ 0.05) in favor of group two at one year from re-evaluation phase regarding defect depth and defect area dimensional changes. CONCLUSION: There was a short-term improvement in group one, which deteriorated over a long period compared with group two, so it is preferable to start orthodontic intrusion before guided tissue regeneration.

Entire papilla preservation technique for treatment of periodontal intrabony defects: a series of cases.

OBJECTIVE: Periodontitis is characterized by bone resorption. Vertical bone loss results in an intraosseous defect. Multiple surgical approaches for treating intrabony defects have shown different grades of effectiveness. Recently, the entire papilla preservation technique has been proposed, improving clinical parameters, such as pocket depth and clinical attachment level. This series of cases aimed to describe the use of the entire papilla preservation surgical technique without using biomaterials to regenerate periodontal intrabony defects. The influence on the clinical periodontal parameters and radiographic parameters was measured through CBCT, the latter not described until now, and analyzed the possible postoperative complications. METHOD AND MATERIALS: A total of six intrabony periodontal defects associated with at least one periodontal pocket with probing depths equal to or greater than 6 mm were treated with the entire papilla preservation technique. The clinical and radiographic parameters were evaluated at the beginning and 6 months after surgery. RESULTS: The mean probing pocket depth reduction was 4.00 ± 0.63 mm, the mean clinical attachment level gain was 3.67 ± 1.03 mm, and the mean radiographic intrabony filling was 2.41 ± 2.03 mm. Early healing was uneventful; the mean visual analog scale at 7 days was 0. CONCLUSIONS: This minimally invasive technique results in an improvement in clinical and radiographic parameters, the latter showing a filling of the bone defect observed during the 6-month evaluation after surgical treatment. These results confirm the importance of clot and flap stability in regenerating intraosseous defects.

Advances in guided bone regeneration membranes: a comprehensive review of materials and techniques.

Guided tissue/bone regeneration (GTR/GBR) is a widely used technique in dentistry to facilitate the regeneration of damaged bone and tissue, which involves guiding materials that eventually degrade, allowing newly created tissue to take its place. This comprehensive review the evolution of biomaterials for guided bone regeneration that showcases a progressive shift from non-resorbable to highly biocompatible and bioactive materials, allowing for more effective and predictable bone regeneration. The evolution of biomaterials for guided bone regeneration GTR/GBR has marked a significant progression in regenerative dentistry and maxillofacial surgery. Biomaterials used in GBR have evolved over time to enhance biocompatibility, bioactivity, and efficacy in promoting bone growth and integration. This review also probes into several promising fabrication techniques like electrospinning and latest 3D printing fabrication techniques, which have shown potential in enhancing tissue and bone regeneration processes. Further, the challenges and future direction of GTR/GBR are explored and discussed.

Cross-Linking Methods of the Silk Protein Hydrogel in Oral and Craniomaxillofacial Tissue Regeneration.

BACKGROUND: Craniomaxillofacial tissue defects are clinical defects involving craniomaxillofacial and oral soft and hard tissues. They are characterized by defect-shaped irregularities, bacterial and inflammatory environments, and the need for functional recovery. Conventional clinical treatments are currently unable to achieve regeneration of high-quality oral craniomaxillofacial tissue. As a natural biomaterial, silk fibroin (SF) has been widely studied in biomedicine and has broad prospects for use in tissue regeneration. Hydrogels made of SF showed excellent water retention, biocompatibility, safety and the ability to combine with other materials. METHODS: To gain an in-depth understanding of the current development of SF, this article reviews the structure, preparation and application prospects in oral and craniomaxillofacial tissue regenerative medicine. It first briefly introduces the structure of SF and then summarizes the principles, advantages and disadvantages of the different cross-linking methods (physical cross-linking, chemical cross-linking and double network structure) of SF. Finally, the existing research on the use of SF in tissue engineering and the prospects of using SF with different cross-linking methods in oral and craniomaxillofacial tissue regeneration are also discussed. CONCLUSIONS: This review is intended to show the advantages of SF hydrogels in tissue engineering and provides theoretical support for establishing novel and viable silk protein hydrogels for regeneration.

Development of a PVA/PCL/CS-Based Nanofibrous Membrane for Guided Tissue Regeneration and Controlled Delivery of Doxycycline Hydrochloride in Management of Periodontitis: In Vivo Evaluation in Rats.

Antibiotic administration is an adjacent therapy to guided tissue regeneration (GTR) in the management of periodontitis. This is due to the major role of pathogen biofilm in aggravating periodontal defects. This study aimed to fabricate a GTR membrane for sustained delivery of doxycycline hydrochloride (DOX) while having a space-maintaining function. The membranes were prepared using a polymeric blend of polycaprolactone/polyvinyl alcohol/chitosan by the electrospinning technique. The obtained membranes were characterized in terms of physicochemical and biological properties. Nanofibers showed a mean diameter in the submicron range of < 450 nm while having uniform randomly aligned morphology. The obtained membranes showed high strength and flexibility. A prolonged in vitro release profile during 68 h was observed for manufactured formulations. The prepared membranes showed a cell viability of > 70% at different DOX concentrations. The formulations possessed antimicrobial efficacy against common pathogens responsible for periodontitis. In vivo evaluation also showed prolonged release of DOX for 14 days. The histopathological evaluation confirmed the biocompatibility of the GTR membrane. In conclusion, the developed nanofibrous DOX-loaded GTR membranes may have beneficial characteristics in favour of both sustained antibiotic delivery and periodontal regeneration by space-maintaining function without causing any irritation and tissue damage.

Hierarchically patterned triple-layered gelatin-based electrospun membrane functionalized by cell-specific extracellular matrix for periodontal regeneration.

OBJECTIVES: Regenerating the periodontium poses a critical challenge in oral medicine. To repair various periodontal defects, it is necessary to adopt a bio-scaffold that provides both the architecture and bioactive cues for local stem cells to migrate, reside, proliferate, and differentiate. The objective of this study is to combine a cell-specific decellularized extracellular matrix (ECM) and a biomimetic electrospinning scaffold to regenerate severely destructed periodontium. METHODS: SEM, water contact angle (WCA), live/dead staining, swelling ratio, tensile test and immune-fluorescent staining were used to define the suitable topography for certain dental stem cells seeding and culturing. Transwell assay, CCK-8, Alizarin Red staining and PCR immune-fluorescent staining were used to determine ideal cell-specific ECM for PDLSCs/BMSCs migration, viability, and oriented differentiation. A biodegradable triple-layered electrospun scaffold (TLS) was fabricated by electrospinning with aligned fibers on both surfaces and a polyporous structure in the middle. The morphology and inter-porous structure of the TLS were characterized by SEM and mercury intrusion porosimetry (MIP). The surface of the TLS was functionalized with cell-specific ECM (Bi-ECM-TLS) through decellularization of the cell sheets cultured on the scaffold. The regenerative outcome of Bi-ECM-TLS was assessed by an in-situ rat periodontal defect model. Micro-CT, HE-staining, Masson's trichome staining, Sirius Red staining and Immunofluorescent staining were used for histological analysis. RESULTS: Aligned Gelatin/PCL fibrous membrane (GPA) was most effective for both PDLSCs and BMSCs in culture with WCA around 50 degrees and better mechanical strength than the rest. MSCs favored the same type of ECM (cell-specific ECM), and their regenerative properties were effectively induced with better chemotaxis, proliferative and differentiating behaviors. TLS characterization showed that TLS possessed aligned-random-aligned structure and inter-porous structure. In a rat model of periodontal defects, the TLS functionalized by BMSC-specific ECM for bone regeneration and PDLSC-specific ECM demonstrated highest BV/TV ratio, best bone structure and ligament fiber orientation and blood vessel formation, suggesting optimal performance in regenerating both alveolar bone and periodontal ligaments over TLS, single-ECM loaded TLS and r-Bi-ECM-TLS. SIGNIFICANCE: This study highlights the importance of combining a cell-specific decellularized ECM and a biomimetic electrospinning scaffold for targeted periodontal tissue regeneration, with potential implications for periodontal tissue engineering and improved patient outcomes.

Research progress on cemental tears in terms of clinical diagnosis and treatment / 口腔疾病防治

@#A cemental tear is defined as an incomplete or complete detachment of the cementum along the dentino-cemental junction (CDJ) or the incremental line within the body of the cementum, which can also involve part of the root dentine adjacent to the cementum. The pathogenesis of cemental tears is not fully elucidated. From the literature review, possible predisposing factors were identified, including tooth type, sex, age, periodontitis, previous periodontal treatment or root canal treatment, history of dental trauma, and occlusal trauma or excessive occlusal force. The morphology of cemental tears can be either piece-shaped or U-shaped, which usually contributes to periodontal and periapical breakdown. Clinically, cemental tears have a unitary periodontal pocket and present with symptoms mimicking localized periodontitis, apical periodontitis, and vertical root fractures. Imaging examination is of great significance for the clinical diagnosis of cemental tears, which often manifest as thin ‘prickle-like’ radiopaque masses located longitudinally adjacent to the affected root surface. Exploratory surgery is needed in some cases. Although intraoperative cemental fragments and cemental lines on the root surface can assist in the diagnostic process, histopathology examination is the gold standard for the diagnosis of cemental tears. The treatment methods vary depending on the timing of the correct diagnosis and the clinical or radiological manifestations. With the development of regenerative biomaterials and the development of intentional replantation, an increasing number of affected teeth can survive for a long time. The aim of this review is to systematically describe the biological basis and predisposing factors, clinical features, radiographic and histological characteristics, diagnosis and clinical management of cemental tears, and treatment outcomes to help make a clear diagnosis and develop a personalized treatment plan.

E7-Conjugated Bio-Inspired Microspheres as a Biological Barrier for Guided Tissue Regeneration.

Guided tissue regeneration (GTR), which is based on creating a physical barrier to prevent the downgrowth of epithelial and connective tissues into the defect site, has been widely used in clinical practice for periodontal regeneration for many years. However, its outcomes remain variable due to highly specific indications, the demand for proficient surgical skills, and frequent occurrence of complications. In this study, we developed a new GTR biomaterial that acts as a biological barrier for epithelial cells and fibroblasts while also serving as a scaffold for bone marrow-derived mesenchymal stem cells (BMSCs) and periodontal ligament stem cells (PDLSCs). This innovative GTR biomaterial is bioinspired injectable microspheres that are self-assembled from nanofibers, and their surfaces are conjugated with E7, a short peptide that selectively promotes BMSC and PDLSC adhesion but inhibits the attachment and spreading of epithelial cells and gingival fibroblasts. The selective affinity afforded by E7 on the surfaces of the nanofibrous microspheres facilitated the colonization of BMSCs in the periodontal defect, thereby substantially improving functional periodontal regeneration, as evidenced by enhanced new bone formation, reduced root exposure, and diminished attachment loss. The remarkable superiority of the bioinspired microspheres over conventional GTR materials in promoting periodontal regeneration underscores the potential of this innovative approach to enhance the efficacy of functional periodontal tissue regeneration.

[Role of collagen membrane in modified guided bone regeneration surgery using buccal punch flap approach: A retrospective and radiographical cohort study].

OBJECTIVE: To investigate whether the placement of absorbable collagen membrane increase the stability of alveolar ridge contour after guided bone regeneration (GBR) using buccal punch flap. METHODS: From June 2019 to June 2023, patients who underwent GBR using buccal punch flap simultaneously with a single implant placement in posterior region (from first premolar to second molar) were divided into coverage group, in which particular bone graft was covered by collagen membrane and non-coverage group. Cone beam CT (CBCT) was taken before surgery (T0), immediately after surgery (T1), and 3-7 months after surgery (T2), and the thickness of the buccal bone plate at different levels (0, 2, 4, and 6 mm) below the smooth-rough interface of the implant (BBT-0, -2, -4, -6) was mea-sured after superimposition of CBCT models using Mimics software. RESULTS: A total of 29 patients, including 15 patients in coverage group and 14 patients in non-coverage group, were investigated in this study. At T0, T1, and T2, there was no significant difference in BBT between the two groups (P>0.05). At T1, BBT-0 was (2.50±0.90) mm in the coverage group and (2.97±1.28) mm in the non-coverage group, with corresponding BBT-2 of (3.65±1.08) mm and (3.58±1.26) mm, respectively. At T2, BBT-0 was (1.22±0.55) mm in the coverage group and (1.70±0.97) mm in the non-coverage group, with corresponding BBT-2 of (2.32±0.94) mm and (2.57±1.26) mm, respectively. From T1 to T2, there were no statistically significant differences in the absolute values [(0.47±0.54)-(1.33±0.75) mm] and percentages [(10.04%±24.81%)-(48.43%±18.32%)] of BBT change between the two groups. The thickness of new bone formation in the buccal bone plate from T0 to T2 ranged from (1.27±1.09) mm to (2.75±2.15) mm with no statistical difference between the two groups at all levels. CONCLUSION: In the short term, the GBR using buccal punch flap with or without collagen membrane coverage can effectively repair the buccal implant bone defect. But collagen membrane coverage showed no additional benefit on alveolar ridge contour stability compared with non-membrane coverage.

A Novel Candidate for Guided Tissue Regeneration: Chitosan and Eggshell Membrane.

Background The primary cause of adult tooth loss is commonly attributed to periodontal disease, a condition that weakens the supportive structures around the teeth. In addressing periodontal diseases, surgeons often employ the guided tissue regeneration (GTR) technique, which involves the use of a barrier membrane. Aim The aim of the present study is to assess the composition and mechanical strength of chitosan and eggshell membrane. This research was conducted to provide insights into their potential application in facilitating tissue regeneration. Materials and procedures Chitosan and eggshell membrane were combined to create the membrane. Scanning electron microscopy (SEM) using FEI Quanta FEG 650 SEM (JSM IT-800, JEOL Ltd., Akishima, Tokyo, Japan) was carried out, and mechanical properties were used to measure the parameters of membrane characterization.  Results In the dry condition, the membrane's tensile strength was 0.30 MPa and its elongation at break was 8.2%. In the wet condition, the membrane's tensile strength was 0.13 MPa and its elongation at break was 22.6%. The SEM results depicted membrane surface with pore sizes ranging from 16 to 100 meters, and the result obtained from membrane porosity test was 31.2%.  Conclusion The chitosan-eggshell membrane exhibited a fibrous surface with a desirable pore size for use as a GTR membrane, but it has low mechanical strength.

Recent Advances in Functionalized Electrospun Membranes for Periodontal Regeneration.

Periodontitis is a global, multifaceted, chronic inflammatory disease caused by bacterial microorganisms and an exaggerated host immune response that not only leads to the destruction of the periodontal apparatus but may also aggravate or promote the development of other systemic diseases. The periodontium is composed of four different tissues (alveolar bone, cementum, gingiva, and periodontal ligament) and various non-surgical and surgical therapies have been used to restore its normal function. However, due to the etiology of the disease and the heterogeneous nature of the periodontium components, complete regeneration is still a challenge. In this context, guided tissue/bone regeneration strategies in the field of tissue engineering and regenerative medicine have gained more and more interest, having as a goal the complete restoration of the periodontium and its functions. In particular, the use of electrospun nanofibrous scaffolds has emerged as an effective strategy to achieve this goal due to their ability to mimic the extracellular matrix and simultaneously exert antimicrobial, anti-inflammatory and regenerative activities. This review provides an overview of periodontal regeneration using electrospun membranes, highlighting the use of these nanofibrous scaffolds as delivery systems for bioactive molecules and drugs and their functionalization to promote periodontal regeneration.

Uso de L-PRF en defectos infraóseos de pacientes con estadios avanzados de periodontitis / Use of L-PRF in intrabone defects in patients with advanced stages of periodontitis

Objetivo: El propósito de este estudio fue observar el efecto del uso de L-PRF en defectos infraoseos de pacientes con periodontitis en estadios avanzados. Métodos: Se incluyeron 32 defectos infraoseos de 12 pacientes con diagnóstico de Periodontitis estadio III y IV (Workshop 2018). Se realizó raspaje a campo abierto con colocación de membrana de L-PRF. Se incluyeron defectos infraóseos de 1-2-3 paredes y cráter óseo. Se registró la profundidad de sondaje (PS), nivel de inserción clínica (NIC), índice de placa (IP) e índice de sangrado (IS). Se realizaron radiografías periapicale digitales antes de la cirugía y al cuarto mes para observar el llenado óseo. Resultados: De los 32 defectos el 75 % mostró disminución de la profundidad de sondaje (PS) y el 66 % mejoro el nivel de inserción clínica (NIC). Se realizó un análisis de correlación pre y posquirúrgico en PS: MV (p = 0,02), MP/L (p = 0,00), DP/L (p = 0,00) y V (p =0,00). El porcentaje de llenado óseo fue de 62,96 % (DS± 3,88). Conclusiones: La mayoría de los defectos infraóseos mostraron radiográficamente llenado óseo parcial o total con el uso de membranas L-PRF. Además, se mejoraron los parámetros clínicos de profundidad de sondaje y nivel de inserción clínica.

Objective: The purpose of this study was to observe the effect of L-PRF (Leuko- cyte-Platelet Rich Fibrin) usage in intraosseous defects in patients with advanced-stages of periodontitis. Methods: Thirty-two intraosseous defects in 12 patients diagnosed with stage III and IV periodontitis (Workshop 2018) were included in the study. Open flap debridement was performed with the placement of L-PRF membranes. Included defects consisted of 1-2-3 wall defects and osseous craters. Parameters such as probing depth (PD), clinical attachment level (CAL), plaque index (PI), and bleeding index (BI) were recorded. Digital periapical radiographs were taken before surgery and at the fourth month to assess bone fill. Results: Out of the 32 defects, 75% showed a reduction in probing depth (PD), and 66% showed improvement in clinical attachment level (CAL). Pre- and post-surgical correlation analysis was performed for PD: MV (p = 0.02), PI/L (p = 0.00), BI/L (p = 0.00), and CAL (p = 0.00). The percentage of bone fill was 62.96% (±3.88 SD). Conclusion: The majority of intraosseous defects exhibited partial or complete radiographic bone fill with the use of L-PRF membranes. Furthermore, clinical parameters such as probing depth and clinical attachment level improved.

Physicochemical properties and cell proliferation and adhesive bioactivity of collagen-hyaluronate composite gradient membrane.

Membrane materials were widely used in guided tissue regeneration (GTR) to prevent fibroblast invasion and form a confined area for preferentially growing of osteoblast. A novel collagen-hyaluronate composite gradient membrane was prepared by Tilapia (Oreochromis mossambicus) skin collagen and sodium hyaluronate for potential GTR applications and their bioactivities were investigated by cellular viability. SEM results indicated the membrane showed a dense outer and a porous inner surface for effectively guiding the growth of bone tissue. Physicochemical and biosafety experiments showed the tensile strength of membrane was 466.57 ± 44.31 KPa and contact angle was 74.11°, and the membrane showed perfect biocompatibility and cytocompatibility as well, which met the requirements of GTR material. Cell morphology revealed that the membrane could facilitate the adherence and proliferation of fibroblast and osteoblast. The results of qRT-PCR and ELISA demonstrated that the membrane could effectively activate TGF-ß/Smad pathway in fibroblast, and promote the expressions of TGF-ß1, FN1 and VEGF. Remarkably, RUNX2 was stimulated in BMP2 pathway by the membrane to regulate osteoblast differentiation. In summary, the collagen-hyaluronate composite gradient membrane not only fulfills the prerequisites for use as a GTR material but also demonstrates substantial potential for practical applications in the field.