Periodontitis is an inflammatory disease attributed to host immune responses to periodontal pathogenic bacteria, characterized by destruction of periodontal tissues, including the cementum, periodontal ligament, and alveolar bone. If left untreated, periodontitis can result in irreversible tissue damage, leading to tooth loss. Thus, periodontal treatment is aimed at controlling bacterial infection. However, while elimination of infection can attenuate the inflammatory condition and interrupt the progression of tissue destruction, it is rarely effective at inducing periodontal tissue regeneration. Importantly, after periodontal treatment, patients are prone to recurrent periodontitis due to reduced cleanability caused by a disrupted gingival line and secondary occlusal damage resulting from lack of supportive tissue. Accordingly, for obtaining full recovery from periodontal disease, successful periodontal tissue regenerative therapy is required.
Much scientific effort has been expended over several decades to develop periodontal tissue regenerative therapy and bone grafts, barrier membranes, and enamel matrix-derivatives have frequently been applied clinically as periodontal tissue regenerative therapy. Furthermore, basic researches focused on biomaterials, cytokines, and stem cells have accelerated the development of reliable periodontal tissue regenerative therapy in the 21st century. In fact, cytokine therapy with the application of recombinant basic fibroblast growth factor has been established in Japan. In addition, several clinical trials using mesenchymal stem cells have been conducted and reported success.
Notwithstanding the aforementioned advances and introduction of novel technologies, there are still numerous issues that need to be resolved by basic research to provide safer, more effective, and reliable periodontal tissue regenerative therapy to all periodontitis patients. Therefore, in this review article, the history and current status of development of cytokine and cell therapies are outlined. Then, solutions for the development of promising periodontal tissue regenerative therapies are introduced, including the efforts of the author's research group. Finally, the latest scientific findings are reviewed, and future research issues to be addressed are discussed.
