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.

Guided bone regeneration (GBR) is a reconstructive procedure of alveolar ridge using membranes. This procedure is indicated when there is no sufficient bone for implantation, or in the case of optimal implant installation for esthetic or functional needs. GBR can be performed before implant placement, when there is not enough bone for initial stability of implants and less predictable outcomes (staged approach), or performed simultaneously with implantation (combined approach). GBR techniques have been used for vertical and horizontal ridge augmentations with acceptable results. This literature review discusses the background, principles of GBR, the materials used in GBR (types of membranes and bone grafts), success criteria and long term results of GBR.

Objectives: Guided bone regeneration (GBR) is one of the most commonly used techniques for alveolar ridge augmentation. With the increasing demand for implant treatments and ridge augmentation, the prevalence of GBR complications has also increased. Herein, we discuss the factors affecting particulate graft integration in the GBR technique, and describe re-treatment of a failed site. Case: GBR with particulate xenograft bone material was performed in a systemically healthy young female. After 6 months, the re-entry surgery revealed failed graft integration despite the clinically normal appearance of the site, and uneventful healing period. The failed site was re-treated successfully with cortical tenting technique, and re-entry revealed integrated graft after 5 months from the second surgery. Conclusion: In addition to the PASS principle to achieve successful results in GBR, the graft particle properties, compaction force of the graft particles, defect characteristics, and waiting time for graft maturation are some of the factors that may affect the results of GBR. Cortical tenting could be a predictable technique for subsequent grafting in failed GBR sites.

The Guided Bone Regeneration (GBR) treatment concept advocates that regeneration of osseous defects is predictably attainable via the application of occlusive membranes, which mechanically exclude non-osteogenic cell populations from the surrounding soft tissues, thereby allowing osteogenic cell populations originating from the parent bone to inhabit the osseous wound. The use of membrane to exclude non-osteogenic cells, is a key principle of guided bone regeneration. A large number of membranes have been evaluated in clinical and experimental studies. The object of this study was to review the literature regarding guided bone regeneration and all types of membranes that were used in this technique. 72 articles between the years 1968 through the 2016 from PubMed, Medline and Google Scholar using the related keywords, were selected. Finally, we concluded that the modification of mechanical and physico-chemical properties of membranes could improve the process of new bone growth. However, determination of the exact role of membrane porosity in this process, still needs to be clarified. Optimization the chemical composition of membrane with the focus and attention to obstructive property and bioactivity, is an important point in this research field. Various factors such as flexibility, mechanical strength and degradation rate determine the type of membrane used for bone tissue regeneration.