A randomized clinical trial on arresting dentine caries in preschool children by topical fluorides--18 month results.

OBJECTIVES: This study aimed to compare the effectiveness of three topical fluoride application protocols in arresting dentine caries in primary teeth of preschool children in a fluoridated area.

METHODS: Children aged 3-4 years who had at least one active dentine caries lesion were randomly allocated into three intervention groups: Group 1-application of 30% silver diammine fluoride (SDF) solution every 12 months; Group 2-three applications of 30% SDF solution at weekly interval at baseline; and Group 3-three applications of 5% sodium fluoride (NaF) varnish at weekly interval at baseline. A masked examiner carried out follow-up examinations every 6 months to assess whether the treated lesions had become arrested.

RESULTS: A total of 304 children with 1670 tooth surfaces with dentine caries received treatment at baseline. After 18 months, 275 children (91%) remained in the study. The caries arrest rates at tooth surface level were 40%, 35% and 27% for Groups 1, 2 and 3, respectively (p<0.001). Result of the multi-level survival analysis showed that the two SDF application protocols could shorten the time to arrest of dentine caries compared with the NaF application protocol. Presence of plaque on lesion surface, tooth type and tooth surface all had significant effects on caries arrest rates.

CONCLUSIONS: Annual or three consecutive weekly applications of SDF solution is more effective in arresting dentine caries in primary teeth than three consecutive weekly applications of NaF varnish.

CLINICAL SIGNIFICANCE: In a water fluoridated area, application of SDF solution, either three weekly applications at baseline or annually, can arrest active dentine caries lesions in primary teeth faster than three weekly applications of NaF varnish at baseline.