periodiden.[化]高碘化物periodn.一段时间；周期；时期；课时；学时；句号；月经periodontal ligament cell牙周膜细胞period-density relation周期密度关系periodontal disease index牙周病指数； 拉塞尔指数period of operating cycle经营周期Periodontal Probing Depth牙周探诊深度period doubing bifurcatio倍周期分岔period of hospitalization住院期period of freezing weather封冻期periodontal dressing paste牙周塞治剂period-cost optimization工期-费用优化