The connection between the periodicity incremental lines of dentin and the secretion rhythm of melatonin of the signaling molecules of biological clock

本研究旨在探讨牙齿牙本质增殖线的周期性与褪黑素作为生物时钟信号分子的作用之间的关系。本实验选用出生后5天和6天、7天和8天的SD大鼠。低浓度褪黑素组浅染色层变窄。在高浓度褪黑素组，这一层消失。随着褪黑素浓度的增加，前牙本质中钙球的数量和大小成比例增加。在褪黑素处理组的门牙和磨牙牙本质中证实了新的增量线。在扫描电子显微镜-能谱分析中，褪黑素处理组与对照组相比，钙、磷含量均有增加。目前认为褪黑素参与了增殖线的形成和成牙本质细胞的钙化机制。

The purpose of the present study is to examine the relationship between the periodicity of incremental lines in dentin of teeth and the role of melatonin that the signaling molecules of biological clock. In this experiment, 5- and 6-day, 7- and 8-days after birth SD rats were used. In the low melatonin concentration group, the light staining layer became narrow. In the high melatonin concentration group, this layer disappeared. The number and size of calcospherites in predentin increased in proportion to the concentration of melatonin administered. The new incremental line was confirmed in both the incisor and molar dentin of the melatonin treated groups. In SEM-EDS analysis, Ca and P content were increasing by the melatonin treated group compared with the control group. It is considered that melatonin participates in the formation of incremental lines and the calcification mechanism of the odontoblast.