One RCT (n was unclear, but appeared to be 452 patients) and one prospective controlled study (n=375) were included. The RCT was blinded for randomisation and evaluation and scored four out of five points on the Jadad scale; the non-randomised study scored two points.
The RCT on decayed primary teeth, permanent molars, or both: For SDF compared with examination, the lowest preventable fractions, for primary teeth, were 55.6% with NNT 1 (95% CI 0.4 to 1.3) for caries arrest and 78.6% with NNT 0.9 (95% CI 0.4 to 1.3) for caries prevention. The highest preventable fractions, for permanent teeth, were 100% with NNT 10 (95% CI 8.4 to 11.2) for caries arrest and 63.6% with NNT 1.4 (95% CI 0.3 to 1.9) for caries prevention. The authors stated that the RCT reported a significant difference between SDF and examination.
The non-randomised study on carious maxillary anterior primary teeth: For SDF compared with water, the lowest preventable fractions were 96.1% with NNT 0.8 (95% CI 0.5 to 1.0) for caries arrest and 70.3% with NNT 0.9 (95% CI 0.4 to 1.1) for caries prevention. For fluoride compared with water, the highest preventable fractions were 21.3% with NNT 3.7 (95% CI 3.4 to 3.9) for caries arrest and 55.7% with NNT 1.1 (95% CI 0.7 to 1.4) for caries prevention. The authors stated that the study reported a significant difference between SDF and fluoride varnishes.
Adverse events: Neither study reported any significant difference between treatment and control groups in pulpal irritation. One study reported a similar incidence of staining in treatment groups and 24-hour tissue sensitivity in three out of 153 patients with SDF.