Caries arrest by topical fluorides in preschool children: 30-month results

Objective: To compare the effectiveness of three applications of silver diammine fluoride (SDF) solution at yearly interval and three applications of SDF solution or sodium fluoride (NaF) varnish at weekly interval at baseline in arresting active caries in the primary teeth of preschool children. Methods: Children aged 3-4 years (n=371) who had at least one active caries lesion (ICDAS codes 3-6) in their primary teeth were randomly allocated into three groups: Group 1 - annual application of 30% SDF solution; Group 2 - three applications of 30% SDF at weekly intervals; and Group 3 - three applications of 5% NaF varnish at weekly intervals. Follow-up examinations were performed every 6 mo nths by the same masked examiner. Results: After 30 months, 309 (83%) children with 1877 caries lesions remained in the study. For cavitated lesions (ICDAS code 5 or 6), the caries arrest rate of Group 1 (48%) was significantly higher than those of Group 2 (33%) and Group 3 (34%), (p < 0.001). Results of multi-level survival analysis showed that the arrest times of cavitated lesions in both SDF groups (Groups 1 and 2) were significantly shorter than that of the NaF varnish group. For moderate caries lesions without visible dentine (ICDAS code 3 or 4), the caries arrest rates were 45%, 44% and 51% in Groups 1, 2 and 3, respectively (p > 0.05). Presence of plaque on caries lesion, tooth type and tooth surface type had an influence on caries arrest. Conclusion: Over a 30-month period, annual applications of SDF solution is more effective than three weekly applications of NaF varnish or SDF solution at baseline in arresting active cavitated dentine caries lesions in primary teeth. Clinical significance: As annual application of SDF solution was found to be more effective than 3 weekly applications of NaF varnish or SDF solution at baseline in arresting active cavitated dentine caries lesions, the former application protocol is preferred for young children who are available for regular caries arrest treatment.