Introduction. Currently, aesthetic and functional dental treatment is widely requested among patients and the demands are increasing. But very rarely when the patient has perfect conditions having often bone deficiency. Guided tissue regeneration is the process of restoring or rebuilding the lost or damaged surface with the ultimate goal of obtaining completely or partially its tissue and function. The main purpose in tissue regeneration of the bone deficient field is to provide optimal and necessary conditions for the implant-prosthetic rehabilitation of the edentulous patient. Implant-supported prosthesis in many cases is possible only due to regenerative methods. Aim of the study. Determination of the effectiveness of the use of bone additions with xenogenic materials and collagen membranes in comparison with autogenous grafts. Materials and methods.. A clinical study has been performed in three patients with different types of bone atrophies. These patients were treated using xeno- and autogenous grafts, as well as with combination of the upper mentioned. In all the cases, buccal bone augmentation has been performed. The postoperative care and healing period (6 months) was evaluated for any healing events. At the end of healing, implants placement has been performed and the integration of graft as well as the quality of bony tissue were appreciated. Results. The use of guided bone regeneration techniques provides satisfactory results under certain conditions and clinical indications. The best result was observed when using autogenic grafts and the Khoury technique. The xeno-genic material usage for GBR without being mixed with the autogenic bone graft did not give successful results due to a poor integration of graft. The usage of collagen and hydroxyapatite for contour grafting showed satisfactory result as a volume maintaining procedure. Conclusions. The use of guided bone regeneration techniques with autogenic bone leads to a significantly higher bone quality compared to xenogenic ones. Application of guided bone regeneration technique with xenogen material can give successful results without mixing with autogenic bone only in situations of contour bone addition, in order to maintain a contour of augmented area.