Arresting caries with silver nitrate and sodium fluoride - 24-month result

Abstract

Objectives: To compare the effectiveness of topical application of 25% silver nitrate (AgNO3) solution followed by 5% sodium fluoride (NaF) varnish with that of 38% silver diamine fluoride (SDF) solution in arresting dentine caries in preschool children. Methods: This is a double-blinded, randomised, non-inferiority trial. Healthy 3-year-old children with active dentine carious surfaces were randomly allocated into two groups: Group A – application of 25% AgNO3 solution followed by 5% NaF varnish on carious surfaces semi-annually, Group B – application of 38% SDF solution followed by placebo varnish on carious surfaces semi-annually. Caries experience and status of the carious surfaces (active or arrested) were recorded at baseline and follow-up examinations. The outcome measure was the number of active carious surfaces that became arrested for each child. This study adopted intention-to-treat analysis. A non-inferiority test was conducted to compare the mean arrested surfaces (MAS) between two groups. Non-inferiority of Group A would be accepted if the lower limit of the confidence interval (CI) for the difference in MAS was greater than -0.5. Results: A total of 1,070 children with active dentine carious surfaces were recruited with 535 children in each group. At baseline, the mean number of active carious lesions was 5.18 in both groups. After 24 months, the MAS in Group A and B were 3.55±3.59 and 3.44±3.59, respectively (t-test, p=0.62). The estimated mean difference of MAS between two groups was 0.11 (95% CI: -0.32 to 0.54). The lower limit of 95% CI was greater than -0.5, indicating that Group A had a non-inferiority effect for caries arrest as Group B. Conclusions: The effect of semi-annual application of 25% AgNO3 solution followed by 5% NaF varnish is not inferior to that of 38% SDF in arresting dentine caries in preschool children after 24 months.