Effects of Enamel Matrix Derivative on Vascular Endothelial Growth Factor Expression and Microvessel Density in Gingival Tissues of Periodontal Pocket: A Comparative Study Simone Domenico Aspriello,* † Antonio Zizzi, ‡ Liana Spazzafumo, § Corrado Rubini, ‡ Teresa Lorenzi, i Daniela Marzioni, i Pedro Bullon, ¶ and Matteo Piemontese* † Background: Vascular endothelial growth factor (VEGF) stimulates proliferation and migration of endothelial cells, and correlates with in- flammatory resolution and periodontal tissue healing. Enamel matrix derivative (EMD) seems to stimulate soft tissue healing. Our aim was to assess if topical EMD application in an instrumented periodontal pocket could affect angiogenesis at the gingival level. Methods: A total of 56 periodontal sites in 28 patients were treated with a single session of comprehensive scaling and root planing under local anesthesia after recording the clinical attachment level (CAL). EMD gel in the test site or only the vehicle propylene glycol alginate in aqueous solution in the control site of the same mouth was applied onto the root surfaces and into the pocket and left in place for 3 min- utes. After 48 hours, gingival biopsies were collected for histologic and immunohistochemical analysis for VEGF and CD34 (for micro- vessel density [MVD] count) antibodies. Statistical comparisons were performed by analysis of variance test. Results: Endothelial VEGF expression and MVD were statistically different in the test site compared to the control site. VEGF expression and MVD of the control site were not correlated with CAL, whereas the test site showed high correlations among CAL and endothelial VEGF or MVD. Conclusions: EMD induces proliferation and viability and angio- genesis of human microvascular cells. Recent clinical and histologic studies found EMD to be useful as an adjunct to scaling and root plan- ing in single-rooted teeth. Our findings may help to understand the mechanisms involved in soft tissue healing, through the ability of EMD to increase angiogenesis at periodontal pockets. J Periodontol 2011;82:606-612. KEY WORDS CD34 antigen; chronic periodontitis; immunohistochemistry; periodontal pocket; tissues; vascular endothelial growth factor. V asculogenesis involves the de novo formation of blood vessels in which en- dothelial progenitor cells assem- ble to form vessels in early development. The primitive ves- sel network subsequently ex- pands and remodels to form a more mature network via an- giogenesis, a process in which new blood vessels sprout from existing blood vessels. 1 Angio- genesis, an essential compo- nent of normal wound healing and repair in which endothelial cells and their precursors ac- tively participate, 2 and facili- tates the removal of debris and assists in the development of a granulation tissue framework for wound closure. 3 The major angiogenic factors include fibro- blast growth factors (initial angiogenic stimuli), platelet- derived growth factor, and vas- cular endothelial growth factor (VEGF) (prolonged angiogenic stimuli). VEGF may contribute to the angiogenic stimuli in wounds by direct effects on proliferating and migrating * Department of Clinical Specialistic and Dental Sciences - Periodontology, Polytechnic University of Marche, Torrette, Ancona, Italy. † Italian National Research Center on Aging, Ancona, Italy. ‡ Department of Neurosciences, Section of Pathologic Anatomy and Histopathology, Polytechnic University of Marche. § MS Statistical Center, Italian National Research Center on Aging. i Department of Molecular Pathology and Innovative Therapies, Section of Anatomy, Polytechnic University of Marche. ¶ Periodontics Department, School of Dentistry, University of Seville, Seville, Spain. doi: 10.1902/jop.2010.100180 Volume 82 • Number 4 606