Lind 1974.

Methods	Stratified random allocation; double‐blind (A); placebo‐controlled; 17% drop‐out rate after 3 years (study duration = 3 years). Main reasons for drop out: moved away, sickness; exclusions based on presence in one interim examination; no differential group losses.
Participants	1167 children analysed at 3 years (available at intermediate and final examination). Age range at start: 7‐12 years (average = 10). Surfaces affected at start: 5.1 DMFS. Background exposure to fluoride: water. Year study began: 1970. Location: Denmark.
Interventions	FT versus PL (SMFP group = 2400 ppm F). Home use/unsupervised, daily frequency assumed. Abrasive system: Al oxide trihydrate.
Outcomes	3yNetDMFS increment ‐ (E+U)(CA)cl+(DR)xr. Reported at 1, 2, and 3 years follow ups. DMFT. ECSI.
Notes	Participants randomised (N = 1407). Baseline characteristics (age, DMFS, DMFT) 'balanced'. Clinical (VT) caries assessment by two examiners; diagnostic threshold = CA/NCA; radiographic assessment (2 postBW) by two examiners; diagnostic threshold = ER/DR; state of tooth eruption included = E/U. Inter‐examiner diagnostic error reported to have no effect on results; reversal rates small and similar in both groups.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	B ‐ Unclear