Fan 2008.

Methods	Trial design: 3‐armed, double‐blind, active/placebo‐controlled and stratified RCT Location: China Number of centres: not reported. Chengdu area, China Recruitment period: study commenced in/before 2005
Participants	Inclusion criteria: not reported Exclusion criteria: children with orthodontic appliances, participating in any other clinical study during the 3 months prior to baseline examination, or a condition impeding participation at baseline were excluded Baseline caries: 3.6 dfs (Gp A: 3.54 (SD 5.34); Gp B: 3.53 (SD 5.62); Gp C: 3.60 (SD 6.07)). Baseline characteristic (dfs) "well balanced" (evaluated participants at 2 years reported only) Age at baseline (years): range 4.0 to 4.5 years; mean 4 years (Gp A: 4.23 years (SD 0.134); Gp B: 4.28 years (SD 0.141); Gp C: 4.19 years (SD 0.129)). Baseline characteristic (age) "well balanced" (evaluated participants at 2 years reported only) Sex: 431 F:567 M (Gp A: 136 F:193 M; Gp B: 141 F:200 M; Gp C: 154 F:174 M). Baseline characteristic (sex) "well balanced" (evaluated participants at 2 years reported only) Any other details of important prognostic factors: background exposure to fluoride: community water supply fluoridated 0.3 ppm F Number randomised: 1200 (group distribution not reported) Number evaluated: 998 at 2 years (present for all assessments) (Gp A: 329; Gp B: 341; Gp C:328) Attrition: dropouts not obtainable. Reasons for attrition not fully reported: "Subjects who did not complete the study dropped out for reasons unrelated to the use of the treatments." Differential losses not assessable
Interventions	Comparison: FT (2 groups) versus PL Gp A (n = assessed 329): SMFP 1500 ppm F; abrasive system Ca‐carbonate; home use/unsupervised, twice daily frequency assumed Gp B (n = assessed 341): SMFP 1500 ppm F; abrasive system not reported silica; home use/unsupervised, twice daily frequency assumed Gp C (n = assessed 328): placebo; abrasive system not reported Ca‐carbonate; home use/unsupervised, twice daily frequency assumed
Outcomes	Primary: 2‐year dfs increment ‐ cl (at 2 years) Secondary: adverse effects Assessments irrelevant to this review's scope: compliance Follow‐up duration: 2 years
Notes	Adverse effects: "Throughout the study, there were no adverse effects on the oral hard or soft tissues, which were observed by the dental examiner, or reported by the subjects when questioned in this regard" Funding source: "This clinical study was funded by the Colgate‐Palmolive Company" Declarations/conflicts of interest: half of the authors were employed by the product manufacturer (3 of 6 authors work at Colgate‐Palmolive Technology Center, New Jersey, USA: Yun Po Zhang; Anthony R Volpe; William DeVizio) Data handling by review authors: Gp A + B versus C for analysis. Combined 2 SMFP 1500 groups with different abrasive systems Other information of note: analysis of covariance adjusted for baseline dfs. Clinical (VT) assessment by 1 examiner. A subsample of 40 children were re‐assessed Kappa > 0.9
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Subjects were randomly assigned..."
Allocation concealment (selection bias)	Unclear risk	Comment: insufficient information
Blinding (performance bias and detection bias) All outcomes	Low risk	Quotes: "...employed a double‐blind..." and "Dentifrices were packaged in white tubes or overwrapped with white tape so as to mask their identity"
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Quotes: "A total of 1200 qualifying children...entered the study" and "Subjects who did not complete the study dropped out for reasons unrelated to the use of the treatments" Comment: number randomised/excluded/withdrawn not reported
Selective reporting (reporting bias)	Low risk	Mean dfs increment. Clinical (VT) assessment only
Baseline characteristics balanced?	Unclear risk	Comment: analysis adjusted for baseline dfs. Baseline data reported for participants completing the trial only. However, groups analysed are similar with respect to sex and mean dfs score at baseline
Free of contamination/co‐intervention?	Unclear risk	Comment: insufficient information. Possibility of contamination during brushing sessions