Untreated dental caries in children remains a public health challenge in poor communities. This prospective controlled clinical trial investigated the effectiveness of a new anti-caries agent, Nano Silver Fluoride (NSF), applied once a year to arrest caries in children. One hundred thirty decayed primary teeth were randomly divided into two groups: NSF as the experimental agent and water as the control group. Teeth were clinically diagnosed and treated by one masked examiner and followed up at seven days and five and 12 months by another calibrated examiner who was blinded to the type of treatment. The criteria of the ICDAS II were followed to determine the activity of lesion and the diagnosis of caries. The Pearson's chi-square test was used to compare the groups during different follow-up exams. At seven days, 81% of teeth in the NSF group exhibited arrested caries, whereas in controls, no teeth had arrested decay (p<0.001) [PF, prevented fraction=81%]. After five months, the NSF group had 72.7% with arrested decay, and the control group had 27.4% (p<0.001) [PF=62.5%]. At 12 months, 66.7% of the lesions treated with NSF were still arrested, while the control group had 34.7% remaining arrested (p=0.003) [PF=50%]. The number need to treat (NNT) at five months was two, and at 12 months, the number was three. The NSF formulation is effective to arrest active dentine caries and not stain teeth. NSF was demonstrated to be effective in arresting caries in children in poor communities.

Mechanochemical reactions during polymer friction or contact produce ionic fragments distributed on positive and negative domains at both surfaces.