The aim of this study was to compare the effectiveness of silver diamine fluoride (38 % SDF)
for arresting dental caries among different frequency of application. A double blind randomized
controlled trial was conducted among 295 children, aged 2 - 5 years who had at least one active
carious lesion on upper anterior teeth at child care centers and kindergartens at Chaleomprakiat and
Bokua districts, Nan. The children were divided into three groups of SDF application: (1) one time per
year; (2) two times per year and (3) three times per year and followed up every 6 month. The progression
of carious lesion was evaluated every 6 month for 12 months. The proportions of active
carious surfaces which turned to arrested carious surfaces among three groups at 6 months were 34.5
%, 38.0 % and 38.8 % and at 12 months were 53.2 %, 60.0 % and 84.5 %, respectively. The mean of
the arrested carious surfaces among three groups at 6 months was 2.2, 2.5 and 2.6 and at 12 months
was 4.6, 5.2 and 6.7. Group 3 times had significant better results than group 2 and 1 times. In conclusion,
the application of SDF 3 times per year provided effectiveness in dental caries arresting among
primary teeth better than group 2 and 1 times per year.