Ji 2007.
| Methods | Trial design: parallel‐group study design, where individuals were randomly assigned to 3 treatment arms Follow‐up: 36 months | |
| Participants | Location: Study setting was community dental clinic, and children were selected from 13 primary schools in Yangpu district of Shanghai, China Inclusion criteria: children with sound permanent first molars (caries status determined by WHO (World Health Organization) criteria) Age at baseline: range 6 to 8 years Baseline caries: not reported but 21% of control teeth without treatment were decayed after 3 years Number randomly assigned: 622 children (1016 molars, on average 1.6 teeth per child) in 3 groups: 205 children in sealant, 207 in fluoride varnish, 210 in control Number evaluated: at 24 months: 641 teeth (321 teeth in sealant group; 320 teeth in fluoride varnish group); at 36 months: 631 teeth (311 teeth in sealant group; 320 teeth in fluoride varnish group) (no information on drop‐out rates of participants) | |
| Interventions | Comparison: glass ionomer fissure sealant vs fluoride varnish
3 treatment arms Group 1: sealant group (Fuji II glass ionomer cement), applied by dentist with help of assistant. No resealing Group 2: silane fluoride varnish group (Fluor Protector 0.1% fluoride), applied by dentist with help of assistant, applied every half year for 3 years Group 3: control (group 1 and group 2 were considered in this review) Co‐interventions: none reported |
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| Outcomes | Sound or carious occlusal surface of molar No information was given on outcome measurement procedure | |
| Notes |
Sealant retention:
After 24 months: retained 65%, partial retained 22%, total loss 13% After 36 months: retained 61%, partial retained 25%, total loss 14% Funding source: no information on funding |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Quote: "622 participants were selected from 13 primary schools, and were randomly divided into 3 groups" Comment: No information on randomisation procedure was provided |
| Allocation concealment (selection bias) | Unclear risk | No information was provided |
| Blinding of outcome assessor (detection bias) | High risk | No information was provided |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Missing data by teeth: at 24 months 6/327 (1.8%) in sealant group and 15/335 (4.5%) in fluoride varnish group; and at 36 months 16/327 (4.9%) in sealant group and 15/335 (4.5%) in fluoride varnish group Comment: Although no information on drop‐out rates of participants was provided, we graded this domain as having 'low' risk of bias because the drop‐out rate of teeth was less than 5% |
| Selective reporting (reporting bias) | Low risk | Comment: Outcomes, caries status and sealant retention were reported in a pre‐specified way |
| Other bias | Unclear risk |
Comparability of groups:
No information was provided on demographic characteristics and on caries risk level at baseline
Co‐interventions: Comment: No information was provided on co‐interventions, such as frequency and methods of teeth brushing, or application of fluoride toothpaste |