Journal of "Regeneration, Reconstruction & Restoration" (Triple R)

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.

Introduction: Millions cases of bone fracture are reported annually worldwide. The conventional methods for the repair often fail. The complications of using routine methods include stimulation of bone repair which should be performed without infection risk and immunologic responses. The aim of this study was cloning and expression of bone morphogenenic protein 2 (BMP2), a key growth factor used in bone repair. Materials and Methods: mRNA was extracted from human maxillary osteosarcoma and reverse transcribed. The BMP2 gene was amplified by PCR and cloned into pETDuet vector and was expressed. Results: The BMP2 gene was expressed successfully and expression was confirmed by western blotting using anti- His tag antibody. Conclusion: Recombinant protein preparation method has been recognized to be accessible and the production is cost effective.

Introduction: Antibiotics are routinely administered in clinical setting for prevention of infections in surgeries and as a routine supplement to the culture medium. The nobility of the present study was to evaluate the effect of two commonly used antibiotics, clindamycin and cefazolin, in dental treatments, on osteogenic capability of periodontal ligament stem cells (PDLSCs). Materials and Methods: PDLSCs were isolated from periodontal ligament (PDL) of the root section out of four healthy extracted teeth. The cells were incubated in the following medium for 28 days: (1) Osteogenic medium (OM) + 5 µm clindamycin (clindamycin group), (2) OM + 5 µm cefazolin (cefazolin group) and (3) OM (control group). Alizarin red staining was performed at days 7, 14, 21, and 28 of induction. Results: Addition of cefazolin to osteogenic medium had no significant effect on osteogenesis comparing to the control group. However, Clindamycin significantly inhibited osteogenesis at days 7 and 21 comparing to the control group (P<0.05), but there was no significant differences at 14 and 28 days. Conclusion: It is demonstrated that clindamycin had inhibitory effects on osteogenesis in early stages, but it promoted osteogenesis in later stages. Cefazolin seems not inhibit osteogenic potential of the cells. Taken together, prescribing cefazolin or clindamycin did not cause any negative effect on osteogenesis for long-term.

Introduction: Previous studies have shown the differentiation of Primordial germ cells (PGCs) from embryonic stem cells (ESCs). However, some PGCs die during the differentiation. Alginate biopolymers have shown to closely mimic an in vivo environment and they are suitable for stem cells viability. The aim of the present study was to asses ESCs apoptosis during differentiation into PGCs in alginate microspheres. Materials and Methods: Mouse ESCs were cultured in ESCs medium, alginate biopolymer and bone morphogenetic protein 4 (BMP4) were utilized as a differentiation factor. The expression of genes B-cell lymphoma 2 (Bcl2), BCL2 Associated X Protein (BAX), octamer-binding transcription factor 4 (Oct4), and VASA as a specific gene for PGCs, were analyzed in the time of differentiation. Results: Expression of apoptosis gene, BAX, in cells entrapped in alginate microspheres; in addition, they were significantly down-regulated and expression of anti-apoptosis gene, Bcl2, was not up-regulated in the entire groups. VASA gene expression was significantly up-regulated in alginate groups. The highest ratio of cells differentiated to putative PGCs belonged to the cells in alginate group without BMP4; based on the analysis of the flow cytometry. Immunocytochemistry staining as well demonstrated differentiation in these cells. Conclusion: It was magnificently attained that down-regulation of apoptosis gene and up-regulation of differentiation gene in alginate beads revealed the survival ability of the putative PGCs in alginate compare to ESCs medium. It was obtained that the improvement of alginate microspheres could assist ESCs differentiation towards the putative PGCs.

Introduction: Matching dental discrepancy (DD) with skeletal discrepancy (SD) in pre-surgical orthodontic preparation is crucial for obtaining a desirable surgical outcomes. The aim of the present study was to compare DD to SD in class III patients with and without extraction of the maxillary second premolars. Materials and Methods: This retrospective cohort study assessed subjects in two groups: the 1^st group included individuals who were afflicted by class III skeletal and underwent non-extraction orthodontic treatment prior to the surgery; the 2^nd group, included: patients who suffered from class III skeletal malocclusion and underwent tooth-extraction orthodontic treatment prior to the surgery. The Wits analysis was applied to establish the apical base relationship between the maxillary and the mandibular arches as measured along the Jacobson occlusal plane. Two angles were applied to determine the upper and lower incisors position to the skeletal base: IMPA (the lower incisor teeth to the mandibular plane) and the upper 1 to SN. The horizontal distance between the upper and lower incisors+2 mm was considered as the dental discrepancy. Results: Forty-six individuals were studied in the 1^st group and 31 patients included in the 2^nd group. The mean for DD was 7.39±3.40 mm in the 1^st group and 9.65±2.57 mm in the 2^nd group. The mean was 11.59±4.9 mm in group 1 and 8.48±2.35 mm in group 2. Pearson’s correlation did not show any significant correlation between dental discrepancy and the skeletal discrepancy in the 1^st group (P˃0.05). A positive correlation was obtained between dental discrepancy and the skeletal discrepancy in the 2^nd group (P˂0.001). Conclusion: It was magnificently attained that extraction of the second premolars of the maxilla could be a better match for DD and SD in the pre-surgical preparation in class III patients with an excessive SD.

The utilization of customized three-dimentional (3D) models based on patient's computed tomography (CT) scan data and by assistance of additive manufacturing/rapid prototyping (AM/RP) techniques for 3D reconstruction is one of the applicable trends for reducing the errors and time saving during surgeries. In the present study, the methodology of the fabrication of a custom-made 3D model based on converting CT scan data to standard triangle language (STL) format for a 33-years old male patient who was suffering from an accident trauma was described. The 3D model of the patient’s skull was fabricated and applied in preoperative planning. It was used for designing a comprehensive plan for rehabilitation of the damaged orbit to restore the appearance and bone reconstruction of the patient. Before fabricating the model, the accuracy of protocols used in converting CT scan data into STL file was evaluated. Then, the model was fabricated by a fused deposition modeling (FDM) machine. Using this procedure led to a maximum of 1.4% difference between the virtual model in the software and the fabricated 3D model in the fracture site. The present technique reduced operation time significantly. In addition, following eight months from the operation, the treatment approach ensured the patient's fractures healing process.

After extraction of posterior mandibular teeth, posterior dentoalveolar maxillary extrusion is a common finding in edentulous patients. As the edentulous area continues to atrophy, there is a continuous loss of bone height and density as well as antral pneumatization. Various techniques can be used for correction of this condition. The present article presents an innovative technique that can correct moderate to severe localized defects of the alveolar process prior to implant placement in the posterior maxillary ridge. The combination of extended tuberosity block bone graft harvesting with modified alveoloplasty (alveolectomy) and quadrilateral open sinus lift (localized inlay tuberosity block bone graft technique) is presented as an alternative to simple alveoloplasty for management of the deficient interarch space and antral pneumatization for prosthetics rehabilitation in the posterior edentulous maxillary segments. Surgical intrusion of the osteotomised bone segment as a corticocancellous block bone graft to the sinus cavity results in adequate interarch space and simultaneous vertical ridge augmentation in deficient posterior maxillary ridge for surgical and prosthetic outcomes without the need to harvest bone from another site. This quick and simple method does not need general anesthesia and has fewer complications. Localized inlay extended tuberosity block bone graft can be used as an alternative to simple alveoloplasty and posterior maxillary segmental osteotomy in distal extended edentulous patients for simultaneous management of unfavorable interocclusal distance and sinus pneumatization.

Introduction: Intra-articular injection has been used in patients with chronic temporomandibular joint (TMJ) pain for several years; however, there are still doubts regarding its effectiveness and duration of action. The aim of this study was to compare the analgesic effects of intra-articular injection of morphine, diclofenac, and isotonic saline on the patients with chronic TMJ pain. Materials and Methods: Sixty-six patients with TMJ pain were enrolled in a prospective randomized double-blind and placebo-controlled clinical study. Patients were randomly allocated into three groups in which 12 patients consisted in each group. The analgesic effect of intermittent morphine injection (10 mg/ml), diclofenac sodium (25mg/ml), and normal saline was evaluated. In each group, pain reduction was evaluated by using visual analog scale (VAS) by following time points: 10, 60 min, and a week after injection. Results: All patients in the three groups experienced pain reduction during the experiment. Among them, patients who received morphine showed significantly more reduction in pain than the other the two groups at 60 minutes (P<0.05) and a week after the second injection (P<0.001). Conclusion: Regardless of the type of treatment, TMJ pain was initially reduced presumably due to the arthrocenthesis effect of the drug or because of the placebo effect. According to the analytical results, 10 mg of morphine had a longer effect on pain reduction followed by diclofenac.