Background: Recently, tissue engineering has been introduced as a regenerative treatment for bone defects. There is some evidence showing bone regeneration from mesenchymal stem cells (MSC) loaded on hydroxyapatite β-tricalcium phosphate (HA/TCP) as a scaffold in large defects. This study aimed to compare the quality and quantity of regenerated bone using Bio-Oss, HA/TCP and MSC loaded HA/TCP scaffolds. Methods: Mesenchymal stem cells were aspirated from iliac crest bone marrow after extracting the first, second and third premolars and the first molar in five mature hybrid dogs. The cells were cultured and their osteogenic differentiation potential was evaluated after the third cell passage using Alizarin red staining in experimental conditions. The HA/TCP scaffold (3 x 3 x 3 mm) was loaded with undifferentiated mesenchymal stem cells. Bilateral bone defects were then prepared in the jaws using trephine burs. The defects were randomly filled with HA/TCP, Bio-Oss, or HA/TCP + MSCs. One defect served as a control and was left as an empty cavity. All defects except the control defect were covered with an absorbable membrane. Histological and histomorphometric evaluations were conducted after 6 weeks and data were subjected to analysis of variance (ANOVA) (p < 0.05). Results: The empty cavity demonstrated more bone formation (60.80%) than the HA/TCP (44.93%) and Bio-Oss (40.60%) (p < 0.05) groups. However, the difference from the HA/TCP + MSCs group was not significant (46.38%) (p > 0.05). Conclusion: An MSC-loaded HA/TCP scaffold is a more effective alternative than Bio-OSS or HA/TCP in inducing bone regeneration.

Bone resorption after tooth extraction is a common problem in implant dentistry. Allografts are one of the therapeutic techniques used to reconstruct the deficient ridge. Although this technique eliminates the need for a surgical donor site, it has yielded contradictory results. The aim of the present pilot study was to evaluate the clinical and radiographic results of the use of demineralized freeze-dried cancellous block allografts (DFDCBAs) in lateral ridge augmentation. Seven patients were included in this study. Lateral reconstruction of bone was performed using DFDCBA with stabilizing screws and resorbable collagen membranes. The ridge width was initially measured during the augmentation surgery. A second measurement was taken 6 months later at the time of implant placement. In addition, cone bean computed tomography images were used at both baseline and at 6-month reentry for measuring the width of bone by applying an acrylic stent with a radiopaque marker at the edentulous area. Paired t test was used to evaluate the statistical differences. The mean increase in the clinical and radiographic ridge widths were 1.70 ± 1.90 and 1.28 ± 1.52 mm, respectively, which were not statistically significant (P = 0.56 and P = 0.067, respectively). The results showed that the use of DFDCBAs in conjunction with resorbable membrane does not yield predictable results in the reconstruction of ridge width deficiencies.

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