Periodontal bioengineering with mesenchymal stem cells

Current periodontal regenerative therapies aim at restitution ad integrum of the periodontal attachment apparatus, which involves periodontal ligament, root cementum, and alveolar bone. Guided tissue regeneration, bioactive agents and bone replacement grafts have been utilized in an attempt to fully restore the lost periodontal tissues. But their predictability has been limited and dependent on patient- and defect-related factors. Consequently, the treatment of most periodontal defects still lacks satisfactory and predictable outcomes. Cell therapies, based on the use of mesenchymal stem cells (MSCs), represent a promising therapeutic strategy in light of recently available published preclinical investigations and clinical studies. The application of MSCs in humans is being performed by two different strategies: (1) the ex vivo culture of undifferentiated MSCs from autologous or allogeneic sources, subjected to specific cell expansion and characterization/differentiation tests to obtain the required cell counts for transplantation; and (2) the use of autologous tissue grafts and micrografts, which apart from MSCs, contain other biologically active cell populations and their extracellular matrix. This review evaluates the current status of MSCs therapy applied for periodontal regeneration, describing not only their mechanism of action, but also their efficacy and safety according to the published evidence