To investigate the risk factors for caries in preschool children to provide a scientific basis for the prevention and treatment of caries in primary teeth.

From July 2017 to September 2017, 183 children aged 3-6 who received treatment for caries in the Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, were randomly selected for recording of the caries status of deciduous teeth, and a questionnaire was collected from their guardians. Risk factors for caries in primary teeth were analyzed using SPSS 21.0 software ．

The mean dmft (decayed, missing and filled teeth) value of all samples was 9.91 ± 5.12. There was no significant difference in dmft between boys (10.38 ± 5.26) and girls (9.55 ± 5.01) (t = -1.088, P > 0. 05). There were 40 cases (21.86%) in the mild caries group (dmft = 3.13 ± 1.34) and 143 cases in the severe group (dmft = 11.80 ± 4.07). Oral hygiene before one year of age, duration of tooth brushing, number of oral hospital examinations and frequency of sugar intake were significantly associated with caries status (P < 0.05). Children who brushed their teeth for less than 2 minutes and consumed sugar frequently had high dmft values. Duration of tooth brushing and frequency of sugar intake were significantly associated with caries in the primary teeth (P < 0.05).

Insufficient tooth brushing time and frequent sugar intake are major risk factors for deciduous caries.