龋齿是严重影响人类健康的疾病,WHO已把龋齿列为世界范围内需要重点防治的三大疾病之一[1]。乳牙龋影响儿童的口腔健康,从而影响儿童全身健康与发育,而且与恒牙龋有关[2]。为了解杭州市学龄前儿童牙齿健康状况,监测乳牙龋流行趋势,为乳牙龋的防治提供依据,2009年在杭州市区内抽 Dental caries is a serious disease that affects human health. WHO has listed caries as one of the three major diseases in the world that require prevention and treatment [1]. Deciduous caries affect children’s oral health, thereby affecting children’s general health and development, but also with the permanent tooth caries [2]. In order to understand the dental health status of preschool children in Hangzhou and to monitor the prevalence of deciduous teeth caries, provide the basis for the prevention and treatment of deciduous teeth caries. In 2009,