Murray 1980.

Methods	Stratified random allocation; double‐blind (A); placebo‐controlled; 23% drop out after 3 years (study duration = 3 years). Natural losses; exclusions based on presence in all follow‐up examinations; no differential group losses.
Participants	1106 children analysed at 3 years (present for all examinations). Age range at start: 11‐13 years (average = 11.9). Surfaces affected at start: 9.9 DMFS. Background exposure to fluoride: data not available for fluoridation status of site. Year study began: 1974. Location: UK.
Interventions	FT (2 groups) versus PL (both SMFP groups = 1000 ppm F). Home use/unsupervised, daily frequency assumed. Abrasive system: Al oxide trihydrate (low and normal abrasivity).
Outcomes	3yNetDMFS increment ‐ cl+ xr. Reported at 3 years follow up. DMFS (U).
Notes	Participants randomised (N = 1431). Baseline characteristics (age, DMFS, TAR) 'balanced'. Clinical (VT) caries assessment by two examiners; diagnostic threshold = NR; radiographic assessment (2 postBW) by two examiners; diagnostic threshold = NR; state of tooth eruption included = E/U. Reproducibility ratios were less than 0.23 for intra‐examiner reproducibility for clinical caries diagnosis and less than 0.16 for radiographic caries diagnosis; inter‐examiner reproducibility ratios was 0.26 and 0.1 respectively.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Low risk	A ‐ Adequate