Davies 2002.

Methods	Trial design: 3‐armed, single‐blind, active‐controlled RCT Location: UK Number of centres: "examinations in 808 schools, in nine districts, throughout the North West of England." Districts include: Blackburn; Bolton; Burnley; Oldham; Salford; Skelmersdale; South Sefton; Tameside; Wigan Recruitment period: study commenced in 1993 (5 health districts), and 1994 (4 health districts)
Participants	Inclusion criteria: not reported Exclusion criteria: not reported Baseline caries: 0 dmfs. Baseline characteristics not quantitatively reported Age at baseline (years): 1 year. Baseline characteristics not reported Sex: baseline characteristics not reported Any other details of important prognostic factors: background exposure to fluoride not reported. Community water supply < 0.1 ppm F Number randomised: 7422 (Gp A: 2488; Gp B: 2472; Gp C: 2462) Number evaluated: 3467 (Gp A: 1186; Gp B: 1176; Gp C: 1369) Attrition: 32% dropout after 5 years. Reasons for attrition: refused to participate (9%), change of residence (19%); product related and dental recommended withdrawals in high fluoride group only (0.07%)
Interventions	Comparison: FT versus FTa Gp A (n = 2488): NaF 1450 ppm; abrasive system not reported; home use/unsupervised, daily frequency assumed Gp B (n = 2472): NaF 440 ppm; abrasive system not reported; home use/unsupervised, daily frequency assumed Gp C (n = 1369): no intervention control
Outcomes	Primary: 5‐year dmft increment ‐ cl; prevalence of caries experience (dmft > 0). Reported at 5 years follow‐up Secondary: none assessed Assessments irrelevant to this review's scope: cost per tooth saved; cost per child saved from caries experience/extraction experience Follow‐up duration: 5 years
Notes	Adverse effects: not reported Funding source: not reported Declarations/conflicts of interest: institutional affiliations reported only Data handling by review authors: aComparator group (n = 2462) receiving no intervention also reported but not considered in this review Other information of note: clinical (VT) caries assessments by trained, standardised, calibrated examiners. Clinical data only. Reliability values not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quotes: "..randomised controlled parallel group clinical trial" and "..centrally allocated to either one of the two test groups or a control group using random number tables"
Allocation concealment (selection bias)	Low risk	Quote: "..centrally allocated to either one of the two test groups or a control group" Comment: centralised allocation
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Quote: "Dental examinations were conducted under blind conditions but as "off the shelf" toothpaste was delivered to the participants, subjects and their families were aware of which toothpaste they were using" Comment: clinical assessors blinded, but participants and their families were not. Participants very young children so knowledge of intervention unlikely to influence outcome
Incomplete outcome data (attrition bias) All outcomes	Low risk	1677/2472 available for examination in low fluoride group; 1696/2488 available in the high fluoride group. Total dropout rate of 32% Comment: dropout rate mainly due to refusal to participate, change of residence; product related and dental recommended withdrawals in high fluoride group only but this number is very small. Reasons for dropouts primarily unlikely to be due to intervention
Selective reporting (reporting bias)	Low risk	Comment: routine caries diagnosis. No radiographs taken; clinical examination only. Caries indices reported: mt, dmft, caries free
Baseline characteristics balanced?	Unclear risk	Comment: no baseline data presented. Study undertaken in deprived areas of North West of England with comparable caries prevalence in 5 year olds
Free of contamination/co‐intervention?	Unclear risk	Comment: contamination possible. Toothpaste supplied for use by children participating in the trial only and not to other family members