The aim of our study was to evaluate the properties of different commercially available resorbable collagen membranes for guided bone regeneration, upon addition of plasma rich in growth factors (PRGF). The structural and morphological details, mechanical properties, and enzymatic degradation were investigated in a new approach, providing clinicians with new data in order to help them in a successful comparison and better selection of membranes with respect to their placement and working condition. Particular characteristics such as porosity, fiber density, and surface topography may influence the mechanical behavior and performances of the membranes, as revealed by SEM/AFM and nanoindentation measurements. The mechanical properties and enzymatic degradation of the membranes were analyzed in a comparative manner, before and after PRGF-modification. The changes in Young modulus values are correlated with the ultrastructural properties of each membrane type. The enzymatic (trypsin) degradation test also emphasized that PRGF-modified membranes exhibit a slower degradation compared to the native ones.
Background and aimsPeriodontitis is a common chronic adult condition that implicates oxidative damage to gingival tissue, periodontal ligament and alveolar bone. This study aimed at assessing the association between the nitro-oxidative stress and the periodontal tissues destructions in experimental rat periodontitis.MethodsPeriodontitis was induced in 15 male albino rats by repetitive lesions to the gingiva adjacent to the inferior incisors, performed daily, for 16 days. On D1, D3, D6, D8, and D16 the onset and evolution of periodontitis were monitored by clinical and histopathological examinations; blood was collected and serum nitro-oxidative stress was evaluated through total nitrites and nitrates, total oxidative status, total antioxidant capacity, and oxidative stress index.ResultsThe results demonstrated that there was a graded and continuous increase in serum levels of total nitrites and nitrates, total oxidative status and oxidative stress index, which was consistent with the severity of periodontal destructions during periodontitis progression. However, total antioxidant capacity was not significantly influenced by the disease progression.ConclusionsIn experimental rat periodontitis, the systemic nitro-oxidative stress was associated with the severity of periodontal destructions assessed clinically and histopathologically. Therefore, systemic nitro-oxidative stress parameters might be used as diagnostic tools in periodontitis.
The results suggest that the anesthetics do not present a considerable hepatotoxicity. The comparative assessment of the two anesthetics shows that sevoflurane is superior to isoflurane.
In the jaws, the healing process of bone defects occurs differently compared with other anatomical sites where healing is done by the formation of scar tissue. This is due to physiological bone remodeling and continuous bone resorption and apposition. In the case of large cysts, there is an increased risk of postoperative infection due to the retraction of the blood clot on the bony walls. The use of plasma rich in growth factors (PRGF), with or without autologous bone addition, for filling the cystic cavities is beneficial not only for its antimicrobial effect, but also due to simultaneously release of growth factors from platelet alpha granules and adhesive proteins. The aim of our work was to emphasize the spontaneous bone healing of the maxilla and mandible after the enucleation of large and medium-sized cysts in asymptomatic patients of different age. The outcome of three patients who underwent surgery for removal of radicular cysts is presented. Imagistic [cone-beam computed tomography (CBCT)] and histological examination was performed aiming to evaluate the quality of new bone at the site of the bone defect, after different time intervals. By using PRGF approach, the healing of mandibular bone occurred 18 months after cystectomy in a smoker patient, 54-year-old, while the healing of maxillary bone using autologous bone mixed with PRGF occurred after six months in a 63-year-old patient. In a young patient (14 years old), the regeneration period was six months, using PRGF and a fibrin cloth for filling the defect.
The aim of this study is to assess Hassall's corpuscles in lamb. Thymus samples were harvested from 10 lambs (3 months old) and histologically processed. From the harvested samples, 5 μm seriated sections were made, stained with Goldner's trichrome method and examined under light microscope. In the medulla of the thymic lobules there are on average 7-8 highly polymorphic Hassall's corpuscles. The majority of the corpuscles (80%) have a diameter between 5 and 50 μm, 15% between 50 and 100 μm and only 5% have a diameter of over 100 μm. Only 20-25% among them have a typical "onion-like" structure, 40-45% present different keratinization degrees and 3-5% are cavitary corpuscles, containing degenerated cell fragments. Hassall's corpuscles in lamb are numerous and highly polymorphic.
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