Effectiveness of silver diamine fluoride solution in arresting early childhood caries

Abstract

Early childhood caries (ECC) is the most prevalent oral disease of children worldwide. Epidemiological studies reported that most of the ECC are left untreated. While young children may not be co-operative enough for conventional restorative treatments, silver diamine fluoride (SDF) can be topically applied on tooth surfaces as a cariostatic agent. Previous clinical trials have confirmed that annual application of 38% SDF is effective in arresting dentin caries in preschool children. However, information about the effectiveness of SDF with different combinations of concentration and frequency is still lacking. This information is important for the optimal application of SDF in the future public health programs for caries control.

This prospective randomized controlled trial aimed to investigate and compare the effectiveness of 12% and 38% SDF when applied annually or biannually in arresting dentin caries of primary teeth of preschool children for 30 months. The two null hypotheses tested were firstly, there is no difference in effectiveness when SDF is applied at 12% or 38% in arresting dentin caries of preschool children; and secondly, there is no difference in effectiveness when SDF is applied annually or biannually in arresting dentin caries of preschool children.

A total of 888 healthy and cooperative K1 children aged 3-4 years with at least one dentin caries surface were recruited and randomized into four treatment groups: Group 1 received annual applications of 12% SDF, Group 2 received biannual applications of 12% SDF, Group 3 received annual applications of 38% SDF, and Group 4 received biannual applications of 38% SDF. Group 3 was assigned as the positive control group. Primary outcome was soft dentin caries surface at baseline that became arrested at the follow-up examinations. Clinical examinations were conducted at the kindergartens every 6 months by the same trained examiner. Parental questionnaires were used to collect the children’s demographic information, oral hygiene related habits, parental satisfaction with children’s dental appearance and dental health at baseline, 18- and 30-month examinations. Adverse effects after treatments including increment of non-vital teeth, complaint about tooth or gingival discomfort, gingival discoloration, and black staining over arrested surfaces were also recorded.

A total of 798 children with 3,268 caries surfaces were examined at 30-month follow-up. The dropout rates of the four groups were similar. The respective proportions of arrested surfaces in Group 1 to Group 4 were 48.7%, 54.0%, 60.6%, and 66.9%, respectively (p < 0.001). The two null hypotheses were rejected. Both concentration and frequency were significantly related to treatment effectiveness, but no significant interaction between these two factors was found. The effect size of concentration was much greater than frequency. Other than a higher proportion of black staining in groups receiving 38% SDF treatments, there were no significant differences in adverse effects among the children in the four treatment groups.

To conclude, SDF is more effective in arresting dentin caries in primary teeth of preschool children at 38% than 12%, and when applied biannually than annually. Clinical significant improvement in effectiveness can be achieved by increasing its concentration.