Held 1968.
| Methods | Trial design: 2‐armed, double‐blind, placebo‐controlled and stratified RCT Location: France Number of centres: 1, Les Vaux Recruitment period: study commenced in 1962 | |
| Participants | Inclusion criteria: not reported Exclusion criteria: not reported Baseline caries: 14.3 DMFS (Gp A: 16.9 DMFS/7.9 DMFT; Gp B: 11.7 DMFS/5.7 DMFT). Baseline characteristics (DMFS, DMFT) not balanced Age at baseline (years): range 15 to 16 years Sex: all male Any other details of important prognostic factors: data unavailable for site fluoridation status Number randomised: 178 (Gp A: 86; Gp B: 92) Number evaluated: 63 at 3 years (present at final assessment. Gp A: 32; Gp B: 31) Attrition: 65% dropout after 3 years (study duration = 3 years). Reasons for high dropout due to age range at which many leave the institutions; no differential group losses | |
| Interventions | Comparison: FT versus PL Gp A (n = 86): NaF‐SnF2 1000 ppm F; abrasive system: not clearly specified (silica used); institution use/supervised, twice a day Gp B (n = 92): placebo; abrasive system: not clearly specified (silica used); institution use/supervised, twice a day | |
| Outcomes | Primary: 3‐year DMFS increment ‐ (E) cl; DMFT (at 3 years); annual CAR Secondary: none reported Assessments irrelevant to this review's scope: none Follow‐up duration: 3 years | |
| 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 (VT) caries assessment by 1 examiner, diagnostic threshold not reported; state of tooth eruption included = E. Intra‐examiner reproducibility checks done | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Quote: "...distributed at random to 2 groups" Comment: translation of report not detailed enough to make a categorical decision regarding sequence generation |
| Allocation concealment (selection bias) | Unclear risk | No information provided |
| Blinding (performance bias and detection bias) All outcomes | Low risk | Quote: "Double blind study" Comment: blind outcome assessment and use of placebo described |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Overall dropout for length of follow‐up: 64.6% in 3 years. Dropout by group: 54/86 FT, 61/92 PL. Reason for losses: participants leaving school (due to age range at which many leave the institutions) Comment: numbers lost are unduly high for length of follow‐up. Although no differential losses between groups are apparent and the only reason given for the missing data is acceptable and balanced between groups, this balance may have occurred by chance, because sample size is too small. Caries data used in analysis pertain to participants present at final examination |
| Selective reporting (reporting bias) | Unclear risk | Outcomes reported:
DMFS increment ‐ (E) cl, reported at 3 years follow‐up
DMFT
annual CAR Comment: trial protocol unavailable. Translation of methods section not detailed enough to make a categorical decision regarding selective outcome reporting |
| Baseline characteristics balanced? | High risk | Prognostic factors reported: DMFS: 16.9 FT, 11.7 PL DMFT: 7.9 FT, 5.7 PL Comment: initial caries (DMFS) appears imbalanced |
| Free of contamination/co‐intervention? | Unclear risk | Translation of report not detailed enough to make a categorical decision regarding any contamination/co‐intervention |