Winter 1989.
| Methods | Trial design: 2‐armed, double‐blind, head‐to‐head RCT Location: UK Number of centres: not reported. Pre‐school children residing in Norwich Health District, UK Recruitment period: study began 1984 | |
| Participants | Inclusion criteria: not reported Exclusion criteria: not reported Baseline caries: 0 DMFS (assumed. No clinical examination undertaken). Baseline characteristics not reported Age at baseline (years): mean 2 years (group distribution not reported). Baseline characteristics not reported Sex: 442 F:463 M (full radiographic data sample only. n = 905) (group distribution not reported). Baseline characteristics not reported Any other details of important prognostic factors: background exposure to fluoride: none reported. Community water supplies fluoridated ‐ ranging from 0.08 to 0.57 ppm F Number randomised: 3040 (group distribution not reported) Number evaluated: 2177 at 3 years available at final clinical examination (Gp A: 1073; Gp B: 1104); 905 available for final clinical and radiological examination (Gp A: 428; Gp B: 477) Attrition: 28% dropout after 3 years (study duration = 3 years). Reasons for attrition not reported; no differential group losses | |
| Interventions |
Comparison: FT versus FT
Gp A (n = evaluated 1073): SMFP NaF 550 ppm; abrasive system: Ca glycerophosphate; home use/supervised, daily frequency assumed Gp B (n = evaluated 1104): SMFP 1055 ppm F; abrasive system: Ca glycerophosphate; home use/supervised, daily frequency assumed |
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| Outcomes | Primary: 3‐year dmfs increment ‐ cl + xr; dmfs; dfmt; ds; fs; proportion developing new caries (at 3 years) Secondary: none assessed Assessments irrelevant to this review's scope: ms; plaque; compliance Follow‐up duration: 3 years | |
| Notes | Adverse effects: not reported Funding source: Beecham Products Declarations/conflicts of interest: not reported Data handling by review authors: n/a Other information of note: clinical (VT) caries assessment by 3 calibrated examiners, radiographic assessment by single examiner. Clinical and radiographic reliability assessed by 10% re‐examination of sample. Kappa scores inter‐rater reliability 0.65 to 0.71. Radiographic assessment by 1 examiner. Kappa scores inter‐rater reliability 0.92 | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Quote: "... randomly allocated" |
| Allocation concealment (selection bias) | Unclear risk | Quote: "... 12 assistants to visit the children's homes on a monthly basis for the next 3 years" Comment: probably done |
| Blinding (performance bias and detection bias) All outcomes | Low risk | Quoted: ".. double‐blind clinical trial" and "... toothpaste was supplied ..... group code" |
| Incomplete outcome data (attrition bias) All outcomes | Unclear risk | Comment: 28% dropout after 3 years for clinical examination alone; 70% dropout for clinical and radiographic examination. Reasons for dropout not stated; no differential group losses. High dropout likely to effect study estimates of treatment effect |
| Selective reporting (reporting bias) | Low risk | Clinical and radiographic assessments, dmfs and dmft indices reported |
| Baseline characteristics balanced? | Unclear risk | Comment: age of participant at start of trial 2 years, no baseline caries assumed for all participants |
| Free of contamination/co‐intervention? | Low risk | Quote: "Sufficient toothpaste was provided for the whole family to avoid mistaken use of another product for the child" Comment: contamination unlikely |