A Cochrane review included 38 studies with a total of 7924 subjects. Fifteen studies evaluated the effects of sealant compared with no sealant (n=3620 in 14 studies plus 575 tooth pairs in one study); 24 studies evaluated one type of sealant compared with another (n=4146); and three trials with evaluated glass ionomer sealant versus no sealant (905 participants). Children were aged from 5 to 16 years. Studies rarely reported the background exposure to fluoride of the participants or the baseline caries prevalence.
Resin-based sealant compared with no sealant: Compared to control without sealant, second or third or fourth generation resin-based sealants prevented caries in first permanent molars in children aged 5 to 10 years (table 1). This caries preventive effect was maintained at longer follow-up but both the quality and quantity of the evidence was reduced.
| Outcome | Relative effect (95% CI) | Control teeth | Sealed teeth (95% CI) | Participants (studies) |
|---|---|---|---|---|
| Dentine caries in permanent molars (follow-up: 2 years) | OR 0.12 (0.08 to 0.19) | 400 per 1000 | 63 per 1000 (38 to 96) | 1 548 children randomised & 1322 evaluated after 2 years (6 studies) |
Glass ionomer sealant compared with no sealant: was evaluated by three studies. Results at 24 months were inconclusive (very low-quality evidence).
Sealant compared with another sealant: the relative effectiveness of different types of sealants is unknown (very low-quality evidence). We included 24 trials that directly compared two different sealant materials. Comparisons varied in terms of types of sealant assessed, outcome measures chosen and duration of follow-up.
Adverse effects: Only four studies mentioned adverse effects and stated that no adverse effects were reported by participants.