Marthaler 1974.

Methods	Random allocation; double‐blind (A); placebo‐controlled; 32% drop out after 6 years (study duration = 6 years). Exclusions based on presence in all follow‐up examinations; no differential group losses.
Participants	109 children analysed at 6* years (present for all examinations). Age range at start: 6‐9 years (average = 7.5). Surfaces affected at start: 2.6 DMFS. Background exposure to fluoride: in solution/salt (suboptimal). Year study began: 1966. Location: Switzerland.
Interventions	FT versus PL (AmF group = 1250 ppm F). Home use/unsupervised, daily frequency assumed. Abrasive system: IMP.
Outcomes	6y*NetDFS increment ‐ (E) (CA)cl+(DR)xr. Reported at 2 and 6 years follow ups. PF‐DFS. postMD‐DFS. antMD‐B‐DFS. DFT. Proportion of children with new DFS.
Notes	Participants randomised (N = 161). Baseline characteristics (DMFS, DMFT, FS, FT, TAR) 'balanced' (DFS baseline data NR). Clinical (V) caries assessment by two examiners; diagnostic threshold = CA and NCA; state of tooth eruption included = E. Radiographic assessment (2 postBW) by two examiners; diagnostic threshold = DR and ER; partial recording. "Sufficient agreement of examiners known from earlier work". *Results at 6 years follow up chosen (reported for all outcomes).
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	B ‐ Unclear