Peterson 1967.
| Methods | Trial design: 3‐armed, double‐blind, placebo‐controlled, stratified RCT Location: USA Number of centres: not reported Recruitment period: study began in/before 1964 | |
| Participants | Inclusion criteria: not reported Exclusion criteria: not reported Baseline caries: 14.3 DMFS (Gp A: 13.65 DMFS; Gp B: 13.91 DMFS; Gp C: 15.20 DMFS) (evaluated participants only). Baseline characteristics (DMFS, DMFT, dental age) "balanced" Age at baseline (years): range 9 to 15 years, mean not reported (dental age (erupted permanent teeth): Gp A: 22.62; Gp B: 22.61; Gp C: 22.77) (evaluated participants only) Sex: not reported, although recorded as used to stratify participants Any other details of important prognostic factors: background exposure to fluoride: data not available for fluoridation status of site Number randomised: 1136 (group distribution not reported) Number evaluated: 954 at 2 years (available at this examination) (Gp A: 323; Gp B: 311; Gp C: 320) Attrition: 16% dropout after 2 years (study duration = 3 years). Reasons for attrition not described; any differential group losses not assessable | |
| Interventions |
Comparison: FT (2 groups) versus 'PL'
Gp A (n = evaluated 323): SnF2 1000 ppm F; abrasive system: Ca pyrophosphate; home use/unsupervised, daily frequency assumed
Gp B (n = evaluated 311): APF 1000 ppm F; abrasive system: IMP; home use/unsupervised, daily frequency assumed Gp C (n = evaluated 320): placebo; abrasive system: not reported; home use/unsupervised, daily frequency assumed |
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| Outcomes | Primary: 2‐yeara DMFS increment ‐ cl + xr; O‐DMFS; BL‐DMFS; MD‐DMFS; DMFT (at 1, 2, 3 years) Secondary: none assessed Assessments irrelevant to this review's scope: n/a Follow‐up duration: 3 years | |
| Notes | Adverse effects: not reported Funding source: partially funded by 1 of the intervention toothpaste's manufacturer, Bristol‐Myers Company, New York. Other partial source of funding not reported Declarations/conflicts of interest: institutional affiliations reported only Data handling by review authors: groups A + B combined versus C in analysis. aResults for 3 years follow‐up not considered (not fully reported) Other information of note: clinical (VT) caries assessment by 1 examiner, diagnostic threshold not reported; state of tooth eruption included not reported; radiographic assessment (3 BW) by 1 examiner, diagnostic threshold not reported. Diagnostic errors not reported | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "Age, sex and family records were supplied to a computing centre, where the subjects were grouped according to these factors and randomly assigned to three groups" Comment: most likely computer generated sequence used |
| Allocation concealment (selection bias) | Low risk | Sequence generated centrally |
| Blinding (performance bias and detection bias) All outcomes | Low risk | Quotes: "The double blind procedure was used throughout the study" and "The dentifrice was supplied in white painted tubes and cartons with 1 of 3 code letters for each dentifrice group" ".. Group 3, a non‐fluoride dentifrice.." and "Radiographs were developed and read later..." 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: 16% (182/1136) in 2 years. Dropout by group: not reported. Reasons for missing data: not reported Comment: numbers lost are not unduly high for 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 the analysis pertain to participants present at final examination (though it was a 2‐year report) |
| Selective reporting (reporting bias) | Low risk | Outcomes reported:
DMFS increment ‐ cl + xr, reported at 1, 2 and 3 years follow‐ups
DMFT
O‐DMFS
BL‐DMFS
MD‐DMF 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:
DMFS: 13.91 FT 1, 13.65 FT 2, 15.20 PL DMFT: 7.63 FT 1, 7.47 FT 2, 8.02 PL dental age: 22.61 FT 1, 22.62 FT 2, 22.77 PL Comment: initial caries appears balanced |
| Free of contamination/co‐intervention? | Low risk | Quote: "The participating children were periodically supplied with toothbrushes and a sufficient amount of dentifrice, the amount varying according to the size of the family" Comment: there is sufficient indication overall of prevention of contamination/co‐intervention |