Markou, N. Pepelassi, E. Vavouraki, H. Stamatakis, H.C. Nikolopoulos, G. Vrotsos, I. Tsiklakis, K., Treatment of periodontal endosseous defects with platelet-rich plasma alone or in combination with demineralized freeze-dried bone allograft: A comparative clinical trial, JOURNAL OF PERIODONTOLOGY, (80), 1911-1919, 2009, 0022-4392