The aim of this study was to investigate the effect of three different scaffolds on the viability and differentiation of adipose-derived mesenchymal stem cells (ADMSCs) to osteoblast for bone regeneration of calvarial defect in rabbit model. Adipose was harvested from the nape of 12 rabbits by direct surgery or hollow-tip cannula. Two standardized circular calvarial defects (case and control), 8 mm in diameter each, were created in all the animals. The animals were divided into 3 different groups. In group 1 (G1), the defect was filled with polyamide + ADMSC. In group 2, poly lactic-co-glycolic acid + ADMSC was used. In group 3, decellularized amniotic membrane + ADMSC was applied. In the control defect, the non-seeded scaffolds were applied for filling the defect. Decellularized pericardial scaffolds were used as a membrane on the scaffolds. The animals were euthanized 2, 4, and 8 weeks of operation and new bone formation was assessed by different analyses. Immunohistochemical (IHC) staining with osteopontin and osteocalcin antibodies was also performed. After 2 weeks of wound healing, minimal bone regeneration was detected in all groups. Almost complete defect closure was observed in all experimental groups after 8 weeks of operation, with the greatest defect closure in the animals treated with polyamide scaffolds as compared to biopsies obtained from control defects and other experimental groups. The maximal tensile load was higher in G1, 4 and 8 weeks postoperatively, suggesting the usefulness of polyamide + ADMSC for bone regeneration in calvarial defects. Results of the IHC staining demonstrated a significant difference between seeded and non-seeded scaffold in both short- and long-term follow-ups (P < 0.05). In addition, a significant difference was observed in enhancement of IHC staining of both markers in polyamide group (seeded or non-seeded) 4 and 8 weeks postoperatively in comparison with other scaffolds. It was concluded that bone regeneration in critical calvarial defect was more successful in seeded polyamide.

In this study, hydroxyapatite nanoparticles containing 10% doxycycline, a structural isomer of tetracycline, was prepared by the co-precipitation method. It was added to collagen solution for the preparation of the scaffold with freeze-casting method in order to develop a composite scaffold with both antibacterial and osteoinductive properties for repairing bone defects. The scaffolds were evaluated regarding their morphology, porosity, degradation and cellular response. The scaffolds for further investigation were added in a rat calvaria defect model. The study showed that after eight weeks, the bone formation was relatively higher in the collagen/nano-hydroxyapatite/doxycycline group with completely filled defect when compared with other groups. Histopathological evaluation showed that the defect in the collagen/nanohydroxyapatite/doxycycline group was fully replaced by the new bone and connective tissue. Our results provide evidence supporting the possible applicability of doxycycline-containing scaffolds for successful bone regeneration.

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Based on the results of this experimental study, both NanoBone and FDBG exhibited a similar effect on bone formation.

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Purpose: The aim of this study was to compare the clinical and radiographical outcomes of two loading protocols of mandibular overdentures supported by two unsplinted implants.Materials and methods: Twenty completely edentulous patients were included in the study. Patients were categorized in two groups each containing 10 patients. In group A, patients received at least two implants in symphysis areas inserted after a minimal flap reflection, and 2 months after implant placement, a mandibular complete denture was connected to the implants using ball attachments. In second group, prosthesis was loaded immediately after placing the implants in symphysis areas without any flap reflection. Patients were examined at 1, 12, 24 and 48 weeks after loading. At postoperative visits, occlusion was checked and the need for any prosthesis maintenance was recorded. Mobility of the implants, radiolucency around the implant and amount of crestal bone loss was checked and measured for both groups during the checkup sessions. Also any prosthetic problems were recorded.Results: After 12 months of loading, in both group no implant failure was reported and the survival rate was 100% in immediate and delay loading groups. Average of bone resorption in control group at the end of study was 0.84 ± 0.05 mm and in the test group was 0.84 ± 0.03 mm. In all patients after every 6 months the plastic O-rings were changed due to frictional wearing. In test group, in three patients the mandibular denture fractured, while, in control group it happened in two patients. In the test group, two patients experienced unbearable pain, while, in the control group seven patients experienced unbearable pain and they needed analgesics. None of the patients in test group experienced edema, swelling and discomfort after surgery due to flapless surgery, while in the control group four patients experienced edema and swelling after surgery. Conclusion:The results of this study suggest that immediate loading of two implants supporting mandibular overdenture has outcomes comparable with conventional loading protocols. This clinical approach offers good stability and comfort while keeping high implant success rate.

Background: Clinicians and policymakers are recognizing the importance of measuring health-related quality of life (HRQL) to inform patient management and policy decisions. Objectives: With regard to relation between cultural differences and quality of life (QoL), in this study the QoL of Iranian patients with conventional complete denture and implant-retained overdenture prosthesis according to the increasing penchant of use of implant-retained overdenture prosthesis and lack of studies in this field in our country, has been compared. Patients and Methods: In this cross-sectional study, cluster sampling was conducted in two stages and 90 edentulous patients (45 patients with conventional complete dentures for two jaws (CD group) and 45 patients with a conventional maxillary complete dentures and implant-retained mandibular denture based on two intercanine implants (IOD group)) with the age of above 35 years were selected according to our inclusion criteria. After obtaining permission from the patients, who had been treated at the selected healthcare and medical treatment centers of Tehran, basic information was obtained by a checklist, including gender, age, educational status and housing status; and QoL was measured by a questionnaire of oral health impact profile (OHIP-20). Results: In the group of IOD, 55.6% of the patients had "good" QoL vs. 46.7% of the patients in CD group. Three patients (6.6%) in both groups had "poor" QoL. No significant relationship was observed between demographic factors and different dimensions of QoL, except the average of "psychological disability" in the patients of CD group, which was higher in women. Conclusions: According to this study results, implant-retained overdenture prosthesis provided better QoL for Iranian patients.

Background: The objectives of this study were to separate and culture mesenchymal stem cells (MSCs) from adipose tissue, examine the expression of surface markers on these cells, and determine their ability to differentiate into osteoblasts in normal medium. Objectives: The objectives of this study were to separate and culture mesenchymal stem cells (MSCs) from adipose tissue, examine the expression of surface markers on these cells, and determine their ability to differentiate into osteoblasts in normal medium. Materials and Methods: Sterile adipose tissue was obtained from the scapular subcutaneous adipose tissue of two rabbits (average weight, 2.8 kg) for cultivation and differentiation by either liposuction with a blunt hallow tip cannula or by direct surgery. The morphology, differentiation, and expression of mesenchymal-specific surface markers of rabbit, such as CD90, CD45, CD73, CD44, and CD105, were examined in cells from the third passage by flow cytometry. The MSCs from adipose tissue were stained with a lentivirus genome for cell tracking. The differentiation of MSCs into osteoblasts was investigated using a specific histological stain, Alizarin red. Results: The identity of adipose tissue cells was confirmed by oil-red O staining and examination under an optical microscope at both the initial stage and after differentiation into mesenchymal cells. The results demonstrated that cells derived from adipose tissue differentiated into mesenchymal cells. The nature of the mesenchymal cells was confirmed by the expression of specific surface markers, including CD90, CD45, CD44, CD73, and CD105, by flow cytometry. Finally, Alizarin red staining confirmed the differentiation of MSCs into osteoblasts. Conclusions: Based on our findings, we conclude that the separation and reproduction of adipose tissue cells is an appropriate method for purification of MSCs in animal studies. Regarding the histomorphometric and flow cytometry analysis results, we demonstrated the differentiation ability of MSCs in normal medium and hope to employ these cells for the regeneration of damaged bone tissues in the future.