However, recent progress in material sciences has provided bioactive properties to scaffold materials for transmitting specific signals to cells that will decode these into biochemical signals. Topography, chemistry, and physical properties are considered to be critical parameters for directing cell fate [11]. This review has focused A1210477 on the following topics: (1) the current status of and strategies for periodontal regeneration; (2) a possible biomaterial design for the scaffold used in periodontal tissue

engineering; (3) a possible interaction between scaffold materials and periodontal tissue cells. For more than three decades, periodontal research has been attempting to discover clinical treatment regimens that can regenerate periodontal tissues with good predictability. These trials successfully developed two types of strategies with the combined use of biomaterials and grafts shown in Table 1. A number of animal and human trials demonstrated that the combined use of bone grafts/implant materials with flap surgery successfully stimulated

alveolar bone regeneration. These grafts/materials include: (1) autogenous grafts; (2) allogeneic graft; (3) xenogeneic grafts, and (4) alloplastic materials Galunisertib in vivo [12]. The use of grafts/biomaterials presumably served as a scaffold for bone formation and contained the bone-forming cells and bone-inducting substances that finally resulted in bone formation. The biological performance of bone grafts can be divided into three interrelated, but not

identical rationales: osteogenesis (the formation of new bone by stem cell lineage derived from graft material); osteoinduction (bone growth by the surrounding immature cells recruited by graft material); and osteoconduction (bone growth on the surface of a material with fabrication) [13]. Autogenous grafts only contain self-bone forming cells that can induce osteogenesis, and still serves as the “golden standard” of bone grafts. The second strategy aimed at regenerating a 3D arrayed structure of lost periodontal tissue including root cementum, alveolar PD184352 (CI-1040) bone, and the PDL with the connective tissue attachment. The biological rationale of this strategy was based on the “Melcher hypothesis” [14], which proposed that the nature of the attachment in periodontal healing depended on the origin of cells (epithelial, gingival connective, bone, PDL) repopulating the area adjacent to the root surface. The hypothesis was successfully demonstrated in a series of animal experiments, and the principal of Guided Tissue Regeneration (GTR) was established [15] and [16]. The cell occlusive membrane of GTR functions to isolate the periradicular bone and root surface wound area from the rest of the tissues to maintain a space for the repopulation of cells originating from the PDL. For this purpose, different barrier materials have been used, both non-resorbable and resorbable (biodegradable).