Use of Leukocyte-and Platelet-Rich Fibrin for Bone Regeneration: A Systematic Review

Introduction: Leukocyte- and platelet- rich fibrin (L-PRF) is a fibrin matrix in which the platelet cytokines, growth factors and cells are trapped and this material has been recruited in reconstruction of various defects. The aim of this study was to systematically review of the published data on the effectiveness of using L-PRF on regeneration of bone defects in oral and maxillofacial surgeries. Materials and Methods: Medline and Cochrane Central databases were searched for related articles up to and including August 2015. Being English, having ≥ four weeks follow-up, and clinical, radiographic, histological and histomorphometric assessments were the inclusion criteria. Results: Twenty-four animal studies and 45 human trials were included that reported the rate of new bone formation (NBF). Also, 38 human reports with low levels of evidence to list evaluating various applications of L-PRF in oral and maxillofacial reconstructions were assessed. Using L-PRF either solely or mixed in human trials was evaluated and divided into six groups of sinus floor augmentation and guided bone regeneration (GBR) technique, socket preservation, periodontal intra-bony defects (PID)  regeneration, peri-apical and endo-periodontal defects treatment, peri-implant bone regeneration and treatment of bisphosphonate-related osteonecrosis of the jaw (BRONJ). Moreover, other uses of L-PRF with bone regeneration purposes in oral and maxillofacial surgeries were discussed. Conclusion: As a consequence, although L-PRF either solely or mixed showed challengeable outcomes in animal studies, it was shown to be effective used to accelerate and enhance new bone formation in human studies. However, future clinical trials in some treatment areas are needed with larger sample sizes and long follow-ups to arrive at an evidence-based conclusion.

Mesenchymal Stem Cell Therapy for Treatment of Craniofacial Bone Defects: 10 Years of Experience

Introduction: Cell delivery in treatment of bone defects has been introduced to promote tissue healing in the recent years. However, no general consensus has been reached regarding the outcome of regenerative medicine for this purpose. The aim of this study was to review our 10 years of experience in application of mesenchymal stem cells (MSCs) in craniofacial bone defects. Applied Methodology: Iliac bone marrow, dental pulp and buccal fat pad were selected to harvest MSCs. Flow cytometric analysis, RT-PCR and differentiation staining including Alizarin red, Oil Red O and Toluidine blue were used to identify MSCs. Four groups of bone substitutes were used for cell delivery: synthetic scaffold [beta-tricalcium phosphate (B-TCP) and hydroxyapatite/tricalcium phosphate (HA/TCP)], xenograft [natural bovine bone mineral (NBBM)], allograft [freeze-dried bone (FDBA), demineralized freeze dried bone] and composite [polycaprolactone/TCP (PCL-TCP), demineralized freeze-dried bone/calcium sulfate]. Rat and rabbit calvaria, dog mandible, rabbit tibia sinus and alveolar cleft defects in human were used as the study models. Histomorphometric and radiomorphological analysis were used to determine new bone formation. Outcomes: Cell-treated groups showed greater new bone formation than cell-free group in all studies. Synthetic scaffolds showed better cell attachment according to scanning electron microscopy (SEM) results. In rat calvarial model, B-TCP loaded with MSCs showed better results than scaffolds carrying platelet rich plasma (PRP). NBBM showed less promising results both in dog mandible and ectopic bone formation in the masseter muscle. FDBA block fixed over a supracrestal defect in dog mandible showed 50% less new bone formation when compared with PCL-TCP as a carrier. Conclusion: More convergence studies with similar protocols of cell cultivation, culture, seeding and delivery should be done in the field of regenerative medicine for better generalizability of results for clinical setting.Keywords: Mesenchymal stem cells; Bone regeneration; Tissue engineering; Craniofacial bon

Comparative Evaluation of Various Mesenchymal Stem Cells in Combination with Β-Tricalcium Phosphate

Introduction: The present study was aimed to evaluate and compare adhesion, proliferation, and differentiation of stem cells originated from dental pulp, Buccal fat pad tissue, umbilical cord blood and bone marrow on the β- TCP scaffold. Materials and Methods: Human mesenchymal stem cells originated from dental pulp, Buccal fat pad tissue, umbilical cord blood and bone marrow were assessed in this study. The characteristics of mesenchymal stem cells evaluated by flow-cytometry. Biological properties such as cell number, alkaline phosphatase (ALP) activity, alizarin red and MTT assay scrutized during cell culture. The morphology of cells culture was also examined using a scanning electron microscope (SEM). The MTT assay results represented that the proliferation was time-dependent and the rate of proliferation and viability of any four mesenchymal stem cells were the same. Results: The SEM of hBFPSCs, hBMSCs, hDPSCs, hUCSCs at 5 days indicated that hBFPSCs have higher attachment. ALP enzyme activities revealed the highest at day 21 when the cells were cultured in differentiation media. The alizarin red staining results indicated a clear mineralization of hBMSCs is dramatically higher from three mesenchymal stem cells. Our findings showed that the origins of MSCs impel their proliferative and osteogenic sufficiency and thus influence their application as a cell sources for bone tissue engineering. Conclusion: Despite BMSCs are the best nominee for cell based bone regeneration according to the existing evidences, in clinical and in vivo conditions there are many circumstances may be encountered bone healing

Bone Tissue Engineering: A Literature Review

Introduction: Classic bone tissue engineering involves use of osteogenic cells, growth factors, and bone scaffolds to generate a graft material to replace the gold standard which is autogenous bone graft. Several modifications have been applied to the classic approach but none of them can fully regenerate bone defects. The current study reviewes the literatures in applications of bone tissue engineering both in vivo and in vitro. Materials and Methods: An electronic search in MEDLINE was conducted and both in vivo and in vitro studies were included using bone scaffolds with or without osteogenic growth factors or stem cells. In vitro studies which did not investigate cell-scaffold interactions and in vivo studies which did not measure new bone formation were excluded. Results: Of 86 studies, 38 concerned in vitro and 48 in vivo studies. These studies were divided into six groups based on scaffold which they used: Synthetic, natural, polymers (non-ceramics), composites (polymer+ceramic), metal-based and nano-scaffolds. The results of the studies were compared in a qualitative manner. In vitro studies were mostly conducted on polymers, while relatively more animal and clinical studies were performed on ceramics. The most commonly used scaffolds, stem cells and growth factor were synthetic ceramics, bone marrow stem cells and bone morphgenic protein 2, respectively. Conclusion: Determination of the most successful approach was not possible due to the presence of several variable and variances in analyzing methods and data report. However, studies which used all three components of BTE, including scaffolds, growth factors and stem cells, showed good results both in vitro and in vivo

Buccal Fat Pad as a Potential Source of Stem Cells for Bone Regeneration:an in vitro Study in Static and Dynamic Culture

Adipose tissues hold great promise in bone tissue engineering since they are available in large quantities as a waste material. The buccal fat pad (BFP) is a specialized mass of adipose tissue that can be easily obtained via the oral cavity without injury to the external body surface. Another advantage of BFP over subcutaneous fat is that its size appears to be similar among different people, independent of body weight and fat distribution. However, limited studies have been conducted on the osteogenic capability of stem cells derived from BFP (BFPSCs). In this study, the BFPSCs were characterized for their osteogenic differentiation potential especially in contact with a synthetic scaffold in a perfusion bioreactor. The features of BFPSCs were compared with bone marrow-derived stem cells (BMSCs) as a well known cell source for bone tissue engineering. Comparing BFPSCs with BMSCs indicated similar morphology, but faster proliferation rate of BMSCs. Moreover, when properly induced for two weeks, BFPSCs resembled BMSCs in the production of bone-specific markers, such as alkaline phosphatase, collagen, bone morphogenic protein (BMP), Runx2, and osteocalcin. Both cell types attached nicely to the pores of a gelatin-coated β-Tricalcium phosphate scaffolds. More osteogenic differentiation potential was observed for both cells under dynamic culture in a perfusion bioreactor compared with static culture. The highest collagen content and BMP production were observed in BFPSCs cultured in the bioreactor for two weeks. These results define BFP as a new, rich, and accessible source of stem cells for tissue engineering purposes

\u3cem\u3eIn vitro\u3c/em\u3e Effect of Graphene Structures as an Osteoinductive Factor in Bone Tissue Engineering: A Systematic Review

Graphene and its derivatives have been well‐known as influential factors in differentiating stem/progenitor cells toward the osteoblastic lineage. However, there have been many controversies in the literature regarding the parameters effect on bone regeneration, including graphene concentration, size, type, dimension, hydrophilicity, functionalization, and composition. This study attempts to produce a comprehensive review regarding the given parameters and their effects on stimulating cell behaviors such as proliferation, viability, attachment and osteogenic differentiation. In this study, a systematic search of MEDLINE database was conducted for in vitro studies on the use of graphene and its derivatives for bone tissue engineering from January 2000 to February 2018, organized according to the PRISMA statement. According to reviewed articles, different graphene derivative, including graphene, graphene oxide (GO) and reduced graphene oxide (RGO) with mass ratio ≤1.5 wt % for all and concentration up to 50 μg/mL for graphene and GO, and 60 μg/mL for RGO, are considered to be safe for most cell types. However, these concentrations highly depend on the types of cells. It was discovered that graphene with lateral size less than 5 µm, along with GO and RGO with lateral dimension less than 1 µm decrease cell viability. In addition, the three‐dimensional structure of graphene can promote cell‐cell interaction, migration and proliferation. When graphene and its derivatives are incorporated with metals, polymers, and minerals, they frequently show promoted mechanical properties and bioactivity. Last, graphene and its derivatives have been found to increase the surface roughness and porosity, which can highly enhance cell adhesion and differentiation

Blood Biomarkers Alterations with Administration of Propofol for Anaesthesia Maintenance during Long term Oral and Maxillofacial Surgeries

Objective: This prospective study performed to evaluate blood biomarkers alterations with administration of propofol for maintenance of anaesthesia during long oral and maxillofacial surgeries in order to estimate the risk of Propofol Infusion Syndrome (PRIS). This rare syndrome often would be happened in long duration or high dose infusion which is characterized by the combination of metabolic acidosis, acute bradycardia and/or asystole, and rhabdomyolysis and can be fatal.Methods: Patients undergoing maxillofacial surgeries (>3h) were the subjects of this quasi experimental prospective clinical trial study. Induction of anaesthesia was performed with midazolam 0.025 mg/kg, fentanyl 2 µg/kg, thiopental sodium 5 mg/kg, and atracurium 0.5 mg/kg. Infusion of propofol was initiated (100 µg/kg/min) for maintenance of anesthesia. Serum potassium level, creatine kinase, lactate and blood PH, were evaluated at baseline, and at 2, 4, 6 hours following the initiation of propofol infusion. Generalized estimating equation was used to evaluate the longitudinal changes for each of the evaluated biomarkers. The relation between the biomarkers and the following factors were appraised by using covariance linear (enter mode) regression  analysis: age, gender, weight, administered dose of dexamethasone and epinephrine, duration of surgery, and a history of trauma prior to surgery.Results: A total of 55 participants, 31 women and 24 men, were studied. The mean duration of surgery was 4.8(1) hours. Despite the rise in the level of potassium and creatine kinase and the reduction of blood PH, no case of hyperkalemia or severe metabolic acidosis was observed. Serum lactate level gradually increased to higher than normal in few patients; though did not necessitate  any intervention. All alterations were statistically significant. Potassium and creatine kinase level at baseline had relation to pre-surgical trauma.Conclusion: Maintenance of anaesthesia with 100 µg/kg/min propofol along with administration of low-dose epinephrine and dexamethasone did not cause clinically important alterations in blood biomarkers during long-duration maxillofacial surgeries and might not cause PRIS

Implant assisted ortho-surgery in edentulous jaws: a clinical report

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