Jensen 1988.
| Methods | Trial design: 2‐armed, double‐blind, placebo‐controlled and stratified RCT Location: USA Number of centres: not reported Recruitment period: study commenced in 1986 | |
| Participants | Inclusion criteria: ≥ 54 years old; ≥ 10 natural teeth; residing in non‐fluoridated community Exclusion criteria: current fluoride treatment receipt; current antibiotic use; severe periodontal disease Baseline caries: 53.35 DMFS (Gp A: 53.1 DMFS (SD 19.84); Gp B: 53.6 DMFS (SD 19.40). Baseline characteristic (DMFS) "balanced" Age at baseline (years): 54 to 93 years (Gp A: mean 68.63; Gp B: mean 68.50). Baseline characteristic (age) "balanced" Sex: 510 F:300 M (Gp A: 254 F:150 M; Gp B: 256 F:150 M) (evaluated participants only). Baseline characteristic (sex) "balanced" Any other details of important prognostic factors: conducted in a non‐fluoridated area (exclusion criteria: water fluoride content in home > 0.3 ppm F) Number randomised: 913 (group distribution not reported) Number evaluated: 810 at 1 year (present at final assessment. Gp A: 404; Gp B: 406) Attrition: 11% dropout after 1 year (study duration = 1 year). Reasons for dropout given. Dropouts not reported by group so unable to state whether differential dropout occurred | |
| Interventions | Comparison: FT versus PL Gp A (n = evaluated 404): SnF 1100 ppm F; abrasive system: not reported; home use (unsupervised) twice daily Gp B (n = evaluated 406): placebo; abrasive system: not reported; home use (unsupervised) twice daily | |
| Outcomes | Primary: 1‐year DMFS increment ‐ cl + xr; DMFS coronal; DFS root (at 1 year) Secondary: none assessed Assessments irrelevant to this review's scope: n/a Follow‐up duration: 1 year | |
| Notes | Adverse effects: not reported Funding source: Procter & Gamble Company and Center for Clinical Studies, College of Dentistry, University of Iowa, USA Declarations/conflicts of interest: institutional affiliations reported Data handling by review authors: n/a Other information of note: clinical (VT) caries assessment according to Radike criteria, number of examiners not reported, diagnostic threshold not reported. Radiographic caries assessment (BW) on posterior interproximal surfaces. No data reported on number of examiners or intra/ inter‐examiner agreement | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Quote: "Within strata, subjects were assigned to treatment groups by random permutations of 2" Comment: not enough information provided |
| Allocation concealment (selection bias) | Unclear risk | Quote: "The groups were assigned at the examination site, using a programmed portable computer…" Comment: not enough information provided |
| Blinding (performance bias and detection bias) All outcomes | Low risk | Quote: "Neither the subjects nor the research staff members were aware of the group to which any subject had been assigned. Test and control dentifrices were identical except for the fluoride content" Comment: blinded |
| Incomplete outcome data (attrition bias) All outcomes | Unclear risk | Quote: "This attrition was essentially random" Comment: overall dropout for length of follow‐up: 11% in 1 year. Dropout by group not stated. Reasons for losses not explicitly reported. Cannot establish whether differential loss between groups as number randomised at baseline not reported. It is unclear if reasons for missing outcome data are acceptable and balanced |
| Selective reporting (reporting bias) | Low risk | Outcomes reported: DMFS increment ‐ cl + xr, reported at 1 year follow‐up DMFS coronal DFS root Comment: trial protocol not available. All expected outcomes were reported and were reported in the usual way |
| Baseline characteristics balanced? | Low risk | Prognostic factors reported: age, sex, baseline coronal DMFS and root DFS Comment: prognostic factors appear balanced |
| Free of contamination/co‐intervention? | Low risk | Quotes: "Cohabitants were assigned by the computer to the same group to eliminate the chance of their accidentally using the wrong dentifrice" and "Subjects were instructed to… desist from use of their regular dentifrice during the study period" Comment: contamination and co‐intervention reduced |