Fissure Sealants or Fluoride Varnish? A Randomized Pragmatic Split-Mouth Trial.

This study aimed to compare the clinical effectiveness of resin-based fissure sealants (FS) and fluoride varnish (FV) in children at high caries risk. A practice-based split-mouth randomized clinical trial was conducted at 9 Public Dental Service (PDS) clinics in Norway. In total, 409 children age 6 to 10 y at high caries risk (d₃mft > 0) meeting inclusion criteria were recruited by dentists and dental hygienists during routine examination. Eligibility criteria were 2 fully erupted first permanent molars (FPMs) in the same jaw, with sound occlusal surfaces or with initial caries. Participation was voluntary, caregivers and eligible children were informed about the study, and written parental consent was obtained. FS and FV were randomly applied on contralateral FPMs in the same jaw, with each participant serving as their own control. FS was applied at baseline and thereafter maintained according to clinicians' conventional procedures, whereas FV was applied at baseline, 6 mo, and 12 mo. The study outcome was success, with no need for invasive treatment (caries control), while failure was defined as dentin carious lesion or restoration. Two-level mixed-effects logistic regression analysis was used to compare FS and FV groups. Of 409 recruited children, 369 (90%) children/tooth pairs were examined after 36 mo. Intention-to-treat analysis showed 94.1% adjusted predicted probability (^aPP) of success (95% confidence interval [CI] 91.7 to 96.4) in the FS group and 89.6% ^aPP (95% CI 86.5 to 92.7) in the FV group. In the adjusted analysis, the FV group had a lower OR for success compared with the FS group (OR 0.54, 95% CI 0.24 to 0.87). In the population studied, the clinical effectiveness of FS was statistically significantly higher compared with FV but below the estimated minimal clinically important difference of 10%.