The prevalence and effectiveness of fissure sealants in Scottish adolescents

The presence of fissure sealants was recorded in 4294 adolescents during a 3-year, double-blind clinical caries trial, conducted in Lanarkshire, Scotland, between 1988 and 1992. Of 68,704 occlusal surfaces examined at baseline, sealants were detected on 7011 (10.2%) surfaces, in 1596 subjects. Of these, 17.4% were judged as incompletely sealed. At the final examination 24.3% of sealants originally recorded as complete were missing, with partial loss observed on a further 18.2% of surfaces. At that time, 21.4% of surfaces 'unsealed but sound' at baseline were recorded as decayed, filled or extracted due to caries, compared with 14.4% of surfaces on which an intact sealant had been recorded (P < 0.001). In contrast, of those surfaces on which the sealant was noted as deficient at the outset, 22.9% were judged to have been affected by caries. This study shows that sealants should be repaired when deficient if they are to be effective.