Hawley 1995.

Methods	Trial design: parallel (2 arms) Location: 45 high schools, Manchester, UK Number of centres: 1 Recruitment period: May to November 1990 Funding source: "This study was supported by Colgate Palmolive Technology Center, NJ, USA"
Participants	Inclusion criteria: 2nd year high school pupils Exclusion criteria: not reported Baseline plaque: not reported Baseline gingivitis: not reported Baseline caries: (DMFT) Gp A: mean 3.72 (SD 2.70); Gp B: mean 3.64 (SD 2.56); (DMFS) Gp A: mean 5.48 (SD 4.67); Gp B: mean 5.32 (SD 4.50) Age at baseline (years): mean 12.7 (SD 0.51); range 11‐13 Gender: not reported Any other details of important prognostic factors: low‐fluoride water supply Number randomised: 4060 (not reported by group) Number evaluated: 3462 (at 30‐month follow‐up) (Gp A: 1717; Gp B: 1745)
Interventions	Comparison: triclosan/copolymer/sodium fluoride versus sodium fluoride Gp A (n = 1717 evaluated): brushing with toothpaste (frequency not reported, i.e. normal use) containing 0.3% triclosan, 2% copolymer, 0.24% sodium fluoride (no baseline prophylaxes) Gp B (n = 1745 evaluated): as above but without triclosan and copolymer Duration of treatment: 30 months
Outcomes	Caries (DFS and DFT mean increments), adverse effects; assessed at 15 and 30 months' follow‐up
Notes	Sample size calculation: allowing for 15% attrition over 30 months, it was calculated that 4000 participants were required to have 80% power at a 5% significance level to detect a 10% difference between caries increments of the 2 groups. The required sample size was achieved Adverse effects: none observed
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "...children were randomly allocated..." Comment: insufficient information on the method of sequence generation Additional information from correspondence: "computer generated random numbers"
Allocation concealment (selection bias)	Low risk	Quote: "...children were randomly allocated..." Comment: not mentioned Additional information from correspondence (with the trial statistician): "no‐one apart from me and independent people labelling the toothpaste knew which groups the participants had been allocated to"
Blinding of participants (performance bias) All outcomes	Low risk	Quote: "double‐blind" Comment: participants did not know which group they were assigned to
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "double‐blind" Comment: the examiner did not know which group the participants they were assessing had been assigned to
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	15% of randomised participants were not included in the final analysis (attrition was not reported by group but authors stated that rates were similar). Reasons for attrition were not described. If the missing participants had a higher mean caries increment in one group than the other, as the attrition rate increased, so would over/understatement of the mean difference
Selective reporting (reporting bias)	Low risk	For a study looking into anticaries effect, we consider that appropriate outcome measures were considered and reported in full
Other bias	Low risk	Quote: "Because of the size of the study sample two examiners...were involved. Training prior to the study and calibration during the examination periods ensured that both achieved and maintained similar levels of caries diagnosis" and "Throughout the study both examiners achieved the required standards for both agreement and reliability" Comment: we consider that the risk of differential diagnostic activity is low. We were unable to identify any other potential source of bias