Mainwaring 1978.

Methods	Stratified random allocation; double‐blind (A); placebo‐controlled; 18% drop out (for all study groups combined) after 3 years (study duration = 3 years). Natural losses; any differential group losses not assessable.
Participants	1107 children analysed at 3 years (available at final examination). Age range at start: 11‐12 years. Surfaces affected at start: 7.9 DFS. Background exposure to fluoride: none reported. Year study began: in/before 1974. Location: UK.
Interventions	FT (2 groups) versus PL (both SMFP groups = 1000 ppm F). Home use/unsupervised, for 1 min, daily frequency assumed. Abrasive system: Ca carbonate in all toothpastes.
Outcomes	3yNetDFS increment ‐ (E)(CA)cl+(ER)xr. Reported at 3 years follow up. PF‐DFS . postMD‐DFS. CIR.
Notes	Participants randomised (numbers for relevant groups NR). Baseline characteristics (age, SAR, DFS) 'balanced'. Clinical (VT) caries assessment by one examiner; diagnostic threshold = CA; state of tooth eruption included = E. Radiographic assessment (2 postBW) by one examiner; diagnostic threshold = ER. Intra‐examiner reproducibility checks for DFS in 10% sample (icc for VT/XR over 0.95); error variance less than 5% of total variance; reversal rate less than 5% of observed DFS increment in all groups.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	B ‐ Unclear