The aim of this study was to investigate the quality of newly formed tissues after using Bio-Oss as a graft material and also to determine the level of bone REGENERATION and bone thickness. The incidence of inflammation and any type of forgein body reaction, following using this material was also studied. Five male sheep of the same age, race, weight and systemic condition were selected and 10 surgical defects (5x5x5mm) were created in their mandibular site. At random, one side was filled with Bio-Oss as the test group and another side as the control group, was not filled with any type of graft material. After 6 monthes, the animals were sacrificed and studied histologically and histomorphometrically. The data were analyzed by Mann-Whitney U test showing that the mean percentage of the regenerated bone and the density of the newly formed bone in the test group were statistically more than the controls (p=O.OO4).No inflammation and forgein body reaction were observed in Bio-Oss group.It is concluded that applying Bio-Oss graft material in bone defects can bear useful results. This material can also be successfully used in the procedures of sinuslift and ridge augmentation for implant placement.

Clinical healing following guided tissue REGENERATION (GTR) in intrabony pockets using a polyurethane membrane was compared to healing following gingival flap surgery (GFS).Ten patients with adult periodontitis and the presence of intrabony defects were selected. Oral hygienic treatments were performed during a 4- week's period prior to surgery.One intrabony defect on each patient was randomly chosen to be treated according to the guided tissue REGENERATION (GTR) procedure. The other side received the control treatment GFS. Test group received the GTP treatment including polyurethane membrane after reflecting the flap and curettage of defect. However, flap surgery and curettage were done in control group.The patients were evaluated for changes in probing depth (PD), clinical attachment level (CAL), recession changes in crystal resorting, and defect bone fill. Clinical examinations were performed again 6 months post operatively.The average of (PD), (CAL) and defect depth (DD) before surgery in test group was 3.23, 13.87 and 7.3 mm respectively and in control group was 3.1, 8.9, 7.4 mm. After 6 months the average of (PD), (CAL) and (DD) was 1.69, 1.68, 3.5 mm, respectively and in control group was 1.24, 1.09, and 2.90 mm. Test group and control group showed successful results in treatment of intrabony defects. Test group showed better results than control.No significant difference was observed between two treatment procedures from the point of view of pocket depth reduction, attachment gain, and recession.The bony fill and crystal resorption results suggest similar clinical potential of GTR procedures compared to GFS in treatment of intrabony pocket. However, in order to gain future insight, larger samples and longer observation periods should be evaluated.

Objective: What lies behind the remarkable potential of some organisms to rebuild themselves after injury, and why aren’t mammals better at it? The limited restorative capacity of human tissues has been attributed to the loss of adequate cell replacement coupled with persistent inflammation with increasing age. Our imaginations have been captivated by mounting evidence for populations of stem cells in adult tissues, perhaps set aside earlier in the embryo, that might be coerced into regenerative service in later life. Stem cells have attracted huge scientific and public interest, not only because they bear the promise of miracle cures for age-related diseases, but also because their medical use is so appealing: stem-cell therapy would augment the human body’s own regenerative capacity, which declines as we grow older.Materials and Methods: Our approach has been to develop mouse models to tinker with mechanisms at work in the mammalian response to damage, disease and ageing, by reducing the impediments to effective REGENERATION. The laboratory mouse is widely considered the model organism of choice for studying the diseases of humans, from whom they differ in only a tiny fraction of their genetic material. A distinguished history of classical genetic experimentation in the mouse has recently gathered speed with the advent of powerful new tools to manipulate the murine genome. The recent launch of several internationally sponsored initiatives for systematic mouse mutagenesis on a large scale using various genetics strategies, along with high throughput phenotyping pipelines, underscores the utility of the mouse for interpreting the mammalian genome, and for generating increasingly more accurate models of human disease.Results: Interventions in growth factor delivery using mouse models support the feasibility of recapturing regenerative capacity by modulating key signaling pathways to restore injured or degenerating mammalian tissues. In each model, distinct cellular components are employed, providing new targets for clinical intervention.Conclusion: The appropriate source of cells for therapeutic applications in regenerative medicine is hotly debated, and much work must be done before stem cell therapy can become a medical reality; even the recent explosion of information on stem cell pluripotency has still not brought us a clear understanding of the underlying molecular biology in any system. Other mechanisms at work in the normal REGENERATION process may be more successfully harnessed to increase the efficiency of stem cell-mediated REGENERATION.

Various materials and techniques have been used in the treatment of periodontal disease to achieve REGENERATION of lost periodontal tissues including cementum, periodontal ligament (PDL) and alveolar bone. The composition, regenerative potential, application and therapeutic characteristics of several regenerative materials have been evaluated in the present study.