Mainwaring 1978.

Methods	Trial design: a5‐armed, double‐blind, placebo‐controlled and stratified RCT Location: UK Number of centres: not reported, although multicentre: conducted in 2 areas: Isle of Wight and South East London Recruitment period: study began in/before 1974
Participants	Inclusion criteria: not reported Exclusion criteria: not reported Baseline caries: 7.9 DFS (Gp A: 7.99 DFS (SD 6.08); Gp B: 8.00 DFS (SD 5.97); Gp C: 7.59 DFS (SD 5.56)). Baseline characteristics (SAR, DFS) "balanced" Age at baseline (years): range 11 to 12 years (Gp A: 11.9 years; Gp B: 11.9 years; Gp C: 11.9 years) (relevant groups evaluated). Baseline characteristics (age) "balanced" Sex: 691 F:416 M (Gp A: 205 F:106 M; Gp B: 288 F:192 M; Gp C: 198 F:118 M) (relevant groups evaluated). Sex imbalance between groups Any other details of important prognostic factors: background exposure to fluoride: none reported. Community water supplies < 0.3 ppm F Number randomised: 2104 (group distribution not reported) Number evaluated: 1718 at 3 years (1107 for groups included in review: Gp A: 311; Gp B: 480; Gp C: 316) Attrition: 18% dropout (for all study groups combined) after 3 years (study duration = 3 years). Natural losses; any differential group losses not assessable
Interventions	Comparison: FT (2 groups) versus PL Gp A (n = evaluated 311): SMFP 1000 ppm F + placebo gel; abrasive system: Ca carbonate in all toothpastes; home use/unsupervised, for 1 min, daily frequency assumed Gp B (n = evaluated 480): SMFP 1000 ppm F + placebo gel; abrasive system: Ca carbonate in all toothpastes; home use/unsupervised, for 1 min, daily frequency assumed Gp C (n = evaluated 316): placebo; abrasive system: Ca carbonate in all toothpastes; home use/unsupervised, for 1 min, daily frequency assumed
Outcomes	Primary: 3‐year net DFS increment ‐ (E) (CA) cl + (ER) xr; PF‐DFS; posterior MD‐DFS; CIR (at 3 years) Secondary: not assessed Assessments irrelevant to this review's scope: n/a Follow‐up duration: 3 years
Notes	Adverse effects: not reported Funding source: grant provided by Beecham Group Ltd, manufacturer of test pastes Declarations/conflicts of interest: not reported Data handling by review authors: a4th (placebo toothpaste + fluoride gel) and 5th trial arms (SMFP 1000 ppm F toothpaste + fluoride gel) excluded from this review due to ineligibility of additional caries preventive measures. Gps A + B differ only in flavouring. Gps A + B versus Gp C in analysis Other information of note: clinical (VT) caries assessment by 1 examiner, diagnostic threshold = CA; state of tooth eruption included = E. Radiographic assessment (2 postBW) by 1 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
Random sequence generation (selection bias)	Unclear risk	Quote: "Participants were stratified according to age, sex and then randomly assigned to one of the treatment groups; children from the same family were assigned to the same group"   Comment: not enough information provided
Allocation concealment (selection bias)	Unclear risk	No information provided
Blinding (performance bias and detection bias) All outcomes	Low risk	Quotes: "The study was of double‐blind design, neither examiner nor participants knowing the identity of the treatment group to which the subjects had been allocated" and "... control group were provided with non‐fluoride toothpaste"  Comment: blind outcome assessment and use of placebo described
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Overall dropout for length of follow‐up: 18.4% 386/2104 in 3 years (for all 5 groups). Dropout by group: not reported. Reasons for losses: not reported Comment: numbers lost were not unduly high given length of follow‐up. It is unclear if there were any differential losses, and if reasons for missing outcome data are acceptable and balanced. Caries data used in analysis pertain to participants present at final examination
Selective reporting (reporting bias)	Low risk	Outcomes reported: DFS increment ‐ (E) (CA) cl + (ER) xr, reported at 3 years follow‐up PF‐DFS posterior MD‐DFS caries incidence rate Comment: trial protocol not available. All pre‐specified outcomes (in Methods) were reported and were reported in the pre‐specified way
Baseline characteristics balanced?	Low risk	Prognostic factors reported: mean age: 142.2 months (for each group) SAR: 87.73 (20.95) FT, 89.38 (20.94) PL DFS: 8.19 (6.01) FT, 7.59 (5.56) PL Comment: initial caries appears balanced between groups
Free of contamination/co‐intervention?	Low risk	Quote: "Sufficient toothpaste was delivered by specifically appointed home visitors at monthly intervals to the subjects' homes for total family requirements" Comment: there is sufficient indication overall of prevention of contamination/co‐intervention