Muhler 1970.

Methods	Stratified random allocation; double‐blind (A); placebo‐controlled; 15% drop out after 1 year (study duration = 1 year). Reasons for attrition NR; differential group losses.
Participants	436 children analysed at 1 year (available at final examination). Age range at start: 5‐16 years (average = 10). Surfaces affected at start: 10.3 DMFS. Background exposure to fluoride: data not available for fluoridation status of site. Year study began: in/before 1967. Location: USA.
Interventions	FT** versus PL (SnF2 group = 1000 ppm F). Home use/unsupervised, daily frequency assumed. Abrasive system: Ca pyrophosphate.
Outcomes	1yDMFS increment ‐ cl+xr. Reported at 6 m and 1 year follow ups. DMFT.
Notes	Participants randomised (N = 510). Baseline characteristics (age, gender, DMFS) with some imbalance. Clinical (VT) caries assessment by one examiner, diagnostic threshold = NR. Radiographic assessment (5‐7 BW) by one examiner; diagnostic threshold = NR. State of tooth eruption included = NR. Diagnostic errors NR. **Na N‐lauroyl sarcosinate/SMFP toothpaste group not considered (additional non‐F active agent used in this group only).
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	B ‐ Unclear