Abstract: PURPOSE: To evaluate the influence of the time of deep caries on eruption of premolars. METHODS: Children in kindergarten in 2010 was selected to check caries of deciduous molars, then baseline data of population and personal oral health records were established. After data collection, from 2010 to 2017, according to the age of deep caries in deciduous molars, they were divided into 4 groups: four-year, five-year, six-year and seven-year. SPSS 20.0 software package was applied to analyze the results. RESULTS: Between 2010 and 2017, 994 children were investigated, including 528 boys and 466 girls. A total of 1220 maxillary first deciduous molars, 1307 maxillary second deciduous molars ,1244 mandibular first deciduous molars and 1253 mandibular second deciduous molars were investigated. At the age of 4 to 7, when the maxillary and mandibular deciduous molars suffered from deep caries, the replacement time of the premolars was earlier than cases with no caries. The difference was statistically significant (P<0.05); When deciduous molar decay occurred in young children, premolars had a tendency to erupt earlier, especially deciduous molars developed deep caries before 5 years, the difference was statistically significant (P<0.05). CONCLUSIONS: Prevention and intervention of dental caries in children is very important. Especially for children under 5 years old, caries in children's molars need early treatment, in order to decrease the impact on normal replacement of permanent teeth.

Key words: Caries in deciduous teeth, Time of tooth eruption, Tooth eruption