Abstract: Objective · To compare the caries prevalence, unmet restoration needs and sealant prevalence between Shanghai 12-year-old native and migrant students from 2013 to 2015.  Methods · From 2013 to 2015, a random cluster sample of 12-year-old native and migrant students was selected from each district in Shanghai. World Health Organization (WHO) indices were used to assess decayed-missing-filled teeth of permanent dentition (DMFT). The prevalence of caries and sealants, caries filling rate, unmet dental restoration needs and the value of DMFT were analyzed using the Mann-Whitney U test and chi-squared test.  Results · A total of 2 500 students were examined from 2013 to 2015, among which 36.8% were migrants. There was no significant difference in caries prevalence and DMFT value between native and migrant students from 2013 to 2015. Sealant prevalence of migrants was significantly lower than that of natives in 2013 (0.8% vs 6.6%) and 2015 (3.0% vs 9.9%). Unmet restoration needs of migrants were significantly higher than those of natives in 2015 (60.5% vs 46.4%).  Conclusion · There was no significant difference in caries prevalence between 12-year-old native and migrant students in Shanghai from 2013 to 2015. But there were lower sealants and higher unmet restoration needs in 12-year-old migrant students than their native counterparts, even though free public dental health services were available to both groups.

Key words: caries, sealant, decayed-missing-filled teeth, migrant