Cahen 1982.

Methods	Stratified random allocation; double‐blind (A); placebo‐controlled; 20% drop out after 3 years (study duration = 3 years). Natural losses and exclusions based on presence in all follow‐up examinations; any differential group losses not assessable.
Participants	2008 children analysed at 3 years (present for all examinations). Age range at start: 6‐8 years (average = 7). Surfaces affected at start: 1.4 DMFS (control group only). Background exposure to fluoride: data not obtained for fluoridation status of site. Year study began: 1977. Location: France.
Interventions	FT (2 groups) versus PL (SMFP group = 1500 ppm F, AmF group = 1500 ppm F). Home use/unsupervised, daily frequency assumed. Abrasive system: IMP in the SMFP and placebo toothpaste, Ca carbonate/ Na and Al silicates in the AmF toothpaste.
Outcomes	3yDMFS increment ‐ cl+xr. Reported at 3 years follow up. DMFT. df‐rate.
Notes	Participants randomised (N = 2500); numbers by group NR. Baseline characteristics (age, gender) 'balanced'. Clinical (V) caries assessment by six examiners; diagnostic threshold = NR; state of tooth eruption included NR. Radiographic assessment (2 postBW) by one examiner; diagnostic threshold NR; partial recording. Inter‐ and intra‐examiner reproducibility of clinical and radiographic caries diagnosis assessed in 10% sample ("good reproducibility, NS difference between or within examiners").
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	B ‐ Unclear