Transplantation of dental pulp-derived cell sheets cultured on human amniotic membrane induced to differentiate into bone.

OBJECTIVE: The usefulness of the amniotic membrane as a cell culture substrate has led to its use in the development of dental pulp-derived cell sheets. We induced osteoblastic differentiation of dental pulp-derived cell sheets and conducted histological and immunological examinations in addition to imaging assessments for regeneration of bone defects. METHODS: Dental pulp cells were obtained by primary culture of the dental pulp tissue harvested from extracted wisdom teeth. These cells were maintained for three to four passages. Subsequently, the dental pulp cells were seeded onto an amniotic membrane to produce dental pulp-derived cell sheets. Following the induction of osteoblastic differentiation, the sheets were grafted into the subcutaneous tissue of the lower back and maxillary bone defect of a nude mouse. Histological and immunological examinations of both grafts were performed. RESULTS: Dental pulp-derived cell sheets cultured on an osteoblast differentiation-inducing medium demonstrated resemblance to dental pulp tissue and produced calcified tissue. Mineralization was maintained following grafting of the sheets. Regeneration of the maxillary bone defect was observed. CONCLUSION: Induction of osteoblastic differentiation of the dental pulp-derived cell sheets may be indicated for the regeneration of periodontal tissue.

Effects of far infrared radiation by isotropic high-density carbon on the human oral mucosa.

OBJECTIVES: Wound healing of the oral mucosal epithelium through the application of far infrared radiation emitted by isotropic high-density carbon was investigated in order to clarify the preventive and therapeutic effects of isotropic high-density carbon on oral mucosal injury. MATERIALS AND METHODS: A carbon massager with an isotropic high-density carbon tip was used. Far infrared radiation was applied to the human buccal mucosal squamous cell carcinoma cell line, HO-1-N-1 using a carbon massager, and cell growth factors and heat shock protein levels were measured using real-time RT-PCR and ELISA. Far infrared radiation was applied to oral mucosal injury in SD rats over time using the carbon massager, and its effects were examined by HE staining and immunostaining. The immunostaining positive rate was measured and analyzed using image analysis software. RESULTS: Far infrared radiation induced stronger mRNA expression and higher HSP27 and HSP70 protein levels on real-time RT-PCR and ELISA than in the control group. The far infrared radiation of oral mucosal injury in rats induced strong positive reactions, and positive rates for Ki67, HSP27, and HSP70 were higher than those in the control group. CONCLUSIONS: The treatment of oral mucosal injury with far infrared radiation emitted by isotropic high-density carbon appears to have promoted heat shock protein production and induced regenerative reactions more strongly than in the control group.