Mitropolous 1984.
| Methods | Trial design: 2‐armed, double‐blind, stratified RCT Location: UK Number of centres: 5 secondary schools in North‐West England, UK Recruitment period: study began in/before 1982 | |
| Participants | Inclusion criteria: not reported Exclusion criteria: not reported Baseline caries: 7.7 DMFS (Gp A: 7.76 DMFS (SD 5.67); Gp B: 7.69 DMFS (SD 5.71)) (evaluated participants only). Baseline characteristics (baseline DMFS, baseline DMFT, surfaces at risk) "balanced" Age at baseline (years): range 12 to 13 years (mean/group distribution not reported) Sex: 379 F:346 M (Gp A: 198 F:167 M; Gp B: 181 F:179 M) (evaluated participants only) Any other details of important prognostic factors: background exposure to fluoride in community water supply < 0.1 ppm F Number randomised: 818 (group distribution not reported) Number evaluated: 725 (Gp A: 365; Gp B: 360) Attrition: 11% dropout. Reasons for attrition: lack of co‐operation, own volition, left study schools, absent at time of final examination; no differential group losses | |
| Interventions | Comparison: FT versus FT Gp A (n = evaluated 365): SMPF 250 ppm F; abrasive system: silica; home use/unsupervised but some children (n = 477, across both groups) also brushed at school under supervision Gp B (n = evaluated 360): SMPF 1000 ppm F; abrasive system: silica; home use/unsupervised but some children (n = 477, across both groups) also brushed at school under supervision | |
| Outcomes | Primary: 32‐month net DFS increment ‐ cl + xr; DMFT increment; DFS increment teeth erupting during the study; DMFT increment teeth erupting during the study (at 32 months) Secondary: not assessed Assessments irrelevant to this review's scope: n/a Follow‐up duration: 32 months | |
| Notes | Adverse effects: not reported Funding source: not reported Declarations/conflicts of interest: not reported Data handling by review authors: n/a Other information of note: clinical caries assessment by 1 examiner | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "... stratified .... before being randomly assigned to one of two study groups" Comment: as author and statistician on study (Helen Worthington) the children were randomised using random numbers from random number table |
| Allocation concealment (selection bias) | Low risk | Comment: not mentioned in trial report, but as author and statistician (Helen Worthington) this was done |
| Blinding (performance bias and detection bias) All outcomes | Low risk | Quotes: "trial was double‐blind neither the subjects not the examiner being aware who was receiving test or control products" and "Control and test dentifrices were indistinguishable in taste and appearance" |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Quotes: ".. dropout rate of 11 per cent (32 months)" and "Of the 93 subjects who failed to complete the trial (51 in control and 42 in control), four were removed from the trial through lack of co‐operation, three left trial of their own choice, 49 left the study schools and 37 were absent at the time of the examination" Comment: low dropout (10% test, 12% control), and balanced between the groups. Reasons not connected to toothpaste |
| Selective reporting (reporting bias) | Low risk | Comment: DMFT, DMFS clinical and combined with radiographs, erupting teeth |
| Baseline characteristics balanced? | Low risk | Comment: balance for baseline sex and caries comparable |
| Free of contamination/co‐intervention? | Low risk | Comment: pupils received dentifrice for home use through post. 3 of 5 schools had daily brushing sessions. This was checked at regular intervals to assess accuracy of trial supervisors |