Pit and fissure sealants applied after permanent molars emerge

Pit and fissure sealants involve filling the grooves on the chewing surfaces of molars with a special resin so food particles can’t get trapped there. After two years, the chance of developing cavities on sealed teeth drops to roughly one‑eighth of what it would be without sealants. Without sealants, about 16% of tooth surfaces develop decay; with sealants, that figure falls to only about 5%. The protective effect remains evident even four years after application.

Each application costs just a few dozen to a couple of hundred yuan — specifically, between 100 and 200 yuan per tooth. No anesthesia is needed, no tooth grinding is required, and the whole procedure takes only a few minutes. Many regions offer free sealant programs for children who meet the age criteria.

This conclusion comes from 38 separate trials involving 7,924 children aged 5–16, all selected and pooled by Cochrane according to strict methodological standards. The studies compared children who received resin‑based sealants with those who did not. For first permanent molars in the 5–10 age group, the odds ratio after 24 months was 0.12 (95% CI 0.08–0.19), meaning the risk of decay was roughly one‑eighth that of untreated teeth. This result is based on seven trials with 1,548 participants randomly assigned and 1,322 actually examined; the overall evidence quality is rated as moderate. If the untreated control group shows 16% decayed surfaces after two years, the sealed group shows only 5.2% (range 3.13%–7.37%). When the control group rate reaches 40%, the sealed group still stays at 6.25% (3.84%–9.63%); at a 70% control rate, the sealed group remains at 19% (12.3%–27.2%). After 48–54 months the odds ratio remains low at 0.21 (0.16–0.28), indicating a risk roughly one‑fifth that of untreated teeth. Authors conclude that resin sealants reduce cavity formation by 11%–51% compared with no sealants after two years. No adverse effects were reported in any of the four trials that monitored side‑effects; however, there is insufficient evidence to determine whether glass‑ionomer sealants perform better than other types.

The first permanent molars — teeth that never get replaced — typically appear around age 6, with the second set emerging near age 12. Sealants should be applied as soon as these molars emerge and before any decay sets in; once a cavity has formed, sealants can no longer be used and filling is required instead. Many regions provide free sealant programs for eligible children, so it’s worth checking with the local Chinese CDC or community health centers. No nationwide document with exact coverage criteria or age limits could be identified for this section, so those details are omitted here. Preventing dental caries remains a key focus of school‑age health screenings; see Section 7 for further information.

Ahovuo-Saloranta A, et al. (2017). Pit and fissure sealants for preventing dental decay in permanent teeth. Cochrane Database of Systematic Reviews. https://doi.org/10.1002/14651858.CD001830.pub5