Materials and methods: A randomized controlled trial was carried out on schoolchildren in southern China. Children in good health and had at least one permanent first molar with deep fissures or fissures with early caries were selected. Subjects were randomly allocated into four groups: Group 1- water as placebo control; Group 2- annual application of a 38% silver diamine fluoride (SDF) solution; Group 3- semiannual application of a 5% NaF varnish; and Group 4- placement of light-cured resin sealant. Two sites in each tooth were treated: mesial pit and distal-palatal groove in upper molar; occlusal fissure and buccal pit/groove in lower molar. Follow-up evaluations were conducted every 6 months by a trained independent examiner using an intra-oral LED light, mouth-mirrors, and CPI probes.
Results: At baseline, 501 children (mean age 9.1 years) were included. The numbers of children in Groups 1 to 4 were 128, 125, 124 and 124, respectively. After 12 months, 493 (98.4%) children were examined. Caries into dentine were found in 2.4%, 0.9%, 1.3%, and 0.3% of the study sites in Groups 1 to 4, respectively (Chi-square test, p=0.002). The differences in caries rates of the treated sites in the three test groups were not statistically significant (Chi-square test, p>0.05).
Conclusions: Based on the findings after 12 months, it is concluded that all of the three test agents, namely SDF solution, NaF varnish and resin sealant, are effective in preventing pit and fissure caries in permanent molars, and that their effectiveness is similar.
Supported by the Research Grants Council of Hong Kong (Project No. HKU771207M)