Study of the effects of different biomaterials on osteogenic differentiation of oral-periosteal cells.

Bone regeneration is currently one of the most important challenges for regenerative med-icine and it is considered an ideal clinical strategy in the maxillo-facial area [1]. Bone resorp-tion of alveolar crest occurring after tooth extraction leads to several risks for future treat-ments, including dental implants. For this reason, alveolar ridge preservation (ARP) has be-come a key component of contemporary clinical dentistry. Several clinical techniques and bone substitute materials can be used to fill the socket after tooth extraction. For all of them, the principle aim is to keep the shape and the size of the bone socket of the extracted tooth allowing inserting the dental implants [2]. The goal of our study was to compare different bio-compatible scaffolds based on PLGA (Fisiograft®), Bioglass (Activioss®) and collagen (Sombrero®) in an in vitro model of tissue engineering for dental applications. The cells used in our study derived from Periosteum obtained from four different patients that underwent socket preservation selected by the School of Dentistry of the University of Pavia, previous informed consent. We created bio-complexes constituted by mesenchymal-periosteal cells seeded on different types of biomaterials and we performed adhesion, morphological, prolif-erative and bone differentiation analyses at different time points (7, 14 and 28 days of cul-ture) in proliferative and osteogenic conditions. Bone differentiation was evaluated by qRT-PCR on genes involved in osteoblast development, like BMP-2, Osteocalcin and Periostin. Our results demonstrated that Sombrero® enhanced adhesion and proliferation of periosteal cells, as highlighted by Haematoxylin-Eosin staining and XTT test (3 and 7 days). Long-term studies (14 and 28 days) demonstrated that periosteal differentiation is about the same among the different materials tested. From these preliminary studies we can conclude that it could be advantageous the clinical use of both collagenic and PLGA scaffolds in order to ameliorate initial colonization and subsequent mechanical support in maxillo-bone regenera-tion