Weisenstein 1972.
| Methods | Trial design: 2‐armed, double‐blind, placebo‐controlled, stratified RCT Location: USA Number of centres: not reported, "several" elementary schools, suburban Columbus, Ohio, USA Recruitment period: study began in/before 1969 | |
| Participants | Inclusion criteria: not reported Exclusion criteria: not reported Baseline caries: 7.0 DMFS (Gp A: 7.01 DMFS (SE 0.387); Gp B: 6.99 DMFS (SE 0.357)). Baseline characteristics (DMFS, DMFT) "balanced" Age at baseline (years): range 5 to 15 years, mean 9.5 years (Gp A: 9.39 years; Gp B: 9.49 years). Baseline characteristic (age) "balanced" Sex: 357 F:337 M (Gp A: 177 F:169 M; Gp B: 180 F:168 M). Baseline characteristic (sex) "balanced" Any other details of important prognostic factors: background exposure to fluoride: none reported. Community water supply fluoride "negligible", F level not reported Number randomised: 694 (Gp A: 346; Gp B: 348) Number evaluated: 402 at 1.8 years (available at final examination) (Gp A: 206; Gp B: 196) Attrition: 42% dropout after 1.8 years (study duration = 1.8 years). Reasons for high dropout described: change of residence, absent on examination day; no differential group losses | |
| Interventions | Comparison: FT versus PL Gp A (n = 346): NaF 1000 ppm F; abrasive system: Ca pyrophosphate; home use/unsupervised, daily frequency assumed Gp B (n = 348): placebo; abrasive system: Ca pyrophosphate; home use/unsupervised, daily frequency assumed | |
| Outcomes | Primary: 1.8‐year DMFS increment ‐ cl + xr; DMFT (at 9 months, 1.4 years, 1.8 years) Secondary: none assessed Assessments irrelevant to this review's scope: n/a Follow‐up duration: 1.8 years (21 months) | |
| Notes | Adverse effects: not reported Funding source: not reported Declarations/conflicts of interest: institutional affiliations reported only Data handling by review authors: results of 1 examiner chosen (Examiner A) Other information of note: clinical (VT) caries assessment by 2 examiners, diagnostic threshold not reported. Radiographic assessment (7 BW) by 2 examiners, diagnostic threshold not reported. State of tooth eruption included not reported. Diagnostic errors not reported | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Quote: "... each child was assigned one of two dentifrices randomly within the strata of age, sex and visual‐tactile DMFS exam results" Comment: not enough information presented |
| Allocation concealment (selection bias) | Unclear risk | No information presented |
| Blinding (performance bias and detection bias) All outcomes | Low risk | Quotes: "The control and test dentifrices were similar in colour, flavour and other properties" and "The examiners had no knowledge of the dentifrice assigned to each child, and the children had no knowledge of the identities of the dentifrices assigned to them. All clinical exams and radiographic interpretations were made independent of previous exam records" 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: 42% in 1.8 years. Dropout by group: 117/348 FT, 113/329 PL. Reasons for losses: change of residence, absent on examination day Comment: numbers lost were unduly high for the length of follow‐up. No differential losses between groups. It is unclear if reasons for missing outcome data are acceptable and balanced. Caries data used in analysis pertain to participants present at final examination |
| Selective reporting (reporting bias) | Low risk | Outcomes reported:
DMFS increment ‐ cl + xr, reported at 9 months, 1.4 and 1.8 years follow‐ups
DMFT 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: 7.01 FT, 6.99 PL DMFT: 4.02 FT, 4.18 PL age: 9.39 FT, 9.49 PL gender: 169 M, 177 F FT; 168 M, 180 F PL Comment: initial caries appears balanced |
| Free of contamination/co‐intervention? | Low risk | Quote: "The possible effect of a non‐study dentifrice was minimized because enough dentifrice was given each child to supply the household for the duration of the study" Comment: there is sufficient indication overall of prevention of contamination/co‐intervention |