Stephen 1994.
| Methods | Trial design: 6‐armed, double‐blind, head‐to‐head, stratified RCT Location: UK Number of centres: not reported. Secondary schools in Lanarkshire, Scotland, UK Recruitment period: study began 1988 | |
| Participants | Inclusion criteria: caries in permanent dentition; dental maturity (≥ 1 erupted second permanent molar) Exclusion criteria: fixed orthodontic appliances Baseline caries: 7.4 DMFS (Gp A: 7.47 (SD 5.94); Gp B: 7.23 (SD 5.65); Gp C: 7.46 (SD 5.89); Gp D: 7.33 (SD 5.77); Gp E: 7.34 (SD 5.51); Gp F: 7.48 (SD 5.96)). Baseline characteristics (DMFS) comparable Age at baseline (years): range 11 to 13 years, mean 12.6 years (group distribution not reported) Sex: not reported Any other details of important prognostic factors: background exposure to fluoride: not reported Number randomised: 4294 (Gp A: 858; Gp B: 860; Gp C: 859; Gp D: 856; Gp E: 429; Gp F: 432) Number evaluated: 3517 at 3 years (available at final examination) (Gp A: 721; Gp B: 698; Gp C: 698; Gp D: 703; Gp E: 344; Gp F: 353) Attrition: 18% dropout (for all study groups combined) after 3 years (study duration = 3 years). Reasons for attrition: change of residence/withdrew (8.4%), absent at final examination (8.6%), fixed orthodontic appliance (1%); no differential group losses | |
| Interventions |
Comparison: FT (6 groups)a
Gp A (n = 858): SMFP 1000 ppm F; abrasive system: silica; home use/unsupervised, daily frequency assumed
Gp B (n = 860): SMFP 1500 ppm F; abrasive system: silica; home use/unsupervised, daily frequency assumed Gp C (n = 859): NaF 1000 ppm F; abrasive system: silica; home use/unsupervised, daily frequency assumed Gp D (n = 856): NaF 1500 ppm F; abrasive system: silica; home use/unsupervised, daily frequency assumed Gp E (n = 429): NaF 1000 ppm F + 3% sodium TMP; abrasive system: silica; home use/unsupervised, daily frequency assumed Gp F (n = 432): NaF 1500 ppm F + 3% sodium TMP; abrasive system: silica; home use/unsupervised, daily frequency assumed |
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| Outcomes | Primary: 3‐year net DMFS increment ‐ cl (VT + FOTI); DMFS increment ‐ xr (at 3 years) Secondary: none assessed Assessments irrelevant to this review's scope: subgingival calculus; plaque; oral pathologies (assessed but not reported); oral hygiene habits (assessed, reported in Chestnutt 1998); compliance Follow‐up duration: 3 years | |
| Notes | Adverse effects: not reported Funding source: not reported Declarations/conflicts of interest: institutional affiliations reported only Data handling by review authors: aGps A + C versus B + D in analysis. TMP groups analysed separately (additional agent in these groups) Other information of note: selected for participation on grounds of caries in the permanent dentition and dental maturity. 42% of children were radiographed at baseline and 86% at final examination (36% at both); being restricted initially for ethical reasons. Clinical (VT and FOTI) caries assessment by 2 examiners. 5% of children re‐examined at each annual examination. Intra‐ and inter‐examiner reliabilities of 0.93 to 0.95 (reliability coefficient) and 0.91 to 0.97 by Kappa for DMFS. All radiographs read by 1 examiner. 5% of radiographs re‐assessed for reproducibility. Kappa 0.87 DFS. Analysis adjusted for examiner, baseline caries, baseline calculus, active type and fluoride level, plus all 2‐way interactions | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Quote: "... subjects allocated by a stratified randomisation process" |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information |
| Blinding (performance bias and detection bias) All outcomes | Low risk | Quotes: "... they [toothpastes] could not be differentiated by appearance, flavour, or other in‐use characteristics. The dentifrices were supplied to participants in coded tubes, ensuring the double‐blind nature of the study" and "double blind" "... carried out under strict observance of the double‐blind principle" Comment: dentrifices could not be identified by appearance, flavour or any other characteristic |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Low attrition rate, mainly due to moving away from area or absent from school on day of examination; did not alter balance between groups. 18% dropout rate at 3 years; unlikely to be due to intervention |
| Selective reporting (reporting bias) | Low risk | Clinical and radiographic assessments |
| Baseline characteristics balanced? | Low risk | Comment: baseline caries scores comparable |
| Free of contamination/co‐intervention? | Low risk | Comment: no apparent cause for concern regarding contamination. Sufficient toothpaste supplied for whole family |