Glass 1978.

Methods	Stratified random allocation; double‐blind (A); placebo‐controlled; 35% drop out after 3 years (study duration = 3 years). Natural losses, increased during 3rd year because an entire grade graduated; exclusions based on presence in all follow‐up examinations; any differential group losses not assessable.
Participants	346 children analysed at 3 years (present for all examinations). Age range at start: 6‐11 years (average = 9). Surfaces affected at start: 4.1 DFS. Background exposure to fluoride: none reported. Year study began: in/before 1974. Location: USA.
Interventions	FT versus PL (SMFP group = 1000 ppm F). School use/supervised, 1g applied daily (appropriate toothpastes and toothbrushes also provided for home use). Abrasive system: Ca carbonate.
Outcomes	3yNetDFS increment ‐ (CA)cl+(ER)xr. Reported at 1, 2 and 3 years follow ups. MD‐DFS. O‐BL‐DFS. DFT. CIR. O‐BL‐CIR. MD‐CIR.
Notes	Participants randomised (N = 533); numbers by group NR. Baseline characteristics (age, DFS, DFT, SAR, TAR) 'balanced'. Clinical (VT) caries assessment (FOTI used) by one examiner; diagnostic threshold = CA; state of tooth eruption included = E/U. Radiographic assessment (2 postBW) by one examiner; diagnostic threshold = ER. Reversals were small in both groups (about 6% of DFS increments) and equally common (NS different).
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	D ‐ Not used