James 1967.

Methods	Random allocation; double‐blind (A); placebo‐controlled; 23% drop out rate after 3 years (study duration = 3 years). Reasons for drop out described with respective total numbers: moved away, unco‐operative, not present on examination day, disliked toothpaste, staining of teeth, others; no differential group losses.
Participants	803 children analysed at 3 years (available at final examination). Age range at start: 11‐12 years. Surfaces affected at start: 11 DFS. Background exposure to fluoride: data not available for fluoridation status of site. Year study began: 1962. Location: UK.
Interventions	FT versus PL (SnF2 group = 1000 ppm F). Home use/unsupervised, daily frequency assumed. Abrasive system: dicalcium pyrophosphate.
Outcomes	3yDFS increment ‐ (E) (CA)cl+(ER)xr. Reported at 3 years follow up. DMFS. DFT. DMFT. postMD‐DFS. Proportion of children with tooth staining.
Notes	Participants randomised (N = 1043). Baseline characteristics (age, DFS, DFT, DMFS, DMFT) 'balanced'. Clinical (VT) caries assessment by one examiner; diagnostic threshold = CA; state of tooth eruption included = E/U. Radiographic assessment (2 postBW) by one examiner; diagnostic threshold = ER. Diagnostic errors NR.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	B ‐ Unclear