ESPE Abstracts

Background: Melatonin is known to regulate a variety of biological processes. The investigation and application of melatonin in oral development have got a lot of attention. The study was performed to investigate the effects of melatonin on development of human dentin formation.

Objective and hypotheses: To investigate the role of melatonin in proliferation and differentiation of human dental pulp cells(hDPCs).

Method: HDPCs were obtained from the human third molars or premolars, cultured in vitro and identified by immunocytochemistry. CCK8 assay were used to evaluate the effect of melatonin (10⁻¹²mol/L,10⁻¹⁰mol/L, 10⁻⁸mol/L)on cells’ proliferation for 1, 2, 3, 4, 5 days. Then the cells were treated with odontogenic medium (OM) and MT (10⁻⁸mol/L). After 7 days’incubation the alkaline phosphatase (ALP) activity was analyzed with the kits and the expression of dentin sialophosphoprotein (DSPP) measured by immunocytochemical staining. Alizarin red staining were used to exam the formation of mineralized nodules in hDPCs treated with OM and MT for 14 days.

Results: HDPCs were isolated cultured successfully and identified as the ecto-mesenchyme-derived cells. CCK8 assay demonstrated that absorbances in various levels of MT groups were lower than in control group in a time- and dose- dependent manner (P<0.05). The ALP activity and DSPP levels of OM+MT group were much higher than that of OM group after 7 days’ incubation (P<0.05). Mineralization nodules were more observed in OM+MT group after 14 days’ treatment.

Conclusion: MT can inhibit the proliferation and stimulate the odontoblast differentiation of hDPCs.