Prevalence and contributing factors of dental caries of 6-year-old children in four regions of China

From 2005 to 2015, the prevalence of dental caries in both primary and permanent dentitions was significantly increased in China. Previous studies have shown that the prevalence of permanent dental caries in school-aged children had already reached 19.7%–54.0%, 97.5% affecting first permanent molars. This study aimed to investigate the prevalence and contributing factors of dental caries in 6-year-old children in four regions of China to provide information for oral health promotion programs