Effect of Fluoridated Sealants on Adjacent Tooth Surfaces: A 30-mo Randomized Clinical Trial

A double-blind randomized
clinical trial was performed in 6- to 7-yr-old schoolchildren to evaluate,
in a 30-mo period, whether the caries increment on the distal surface of the
second primary molars adjacent to permanent first molars sealed with fluoride release compounds would be
lower with respect to those adjacent to permanent first molars sealed with a
nonfluoridated sealant. In sum, 2,776 subjects were enrolled and randomly
divided into 3 groups receiving sealants
on sound first molars: high-viscosity glass ionomer cement (GIC group);
resin-based sealant with fluoride (fluoride-RB group); and a resin-based
sealant without fluoride (RB group).
Caries (D1 – D3 level) was recorded on the distal surface of the second primary molar, considered the unit of analysis
including only sound surfaces at the baseline. At baseline, no differences
in caries prevalence were recorded in the 3 groups regarding the considered
surfaces. At follow-up, the prevalence of an affected unit of analysis was
statistically lower (p = .03) in the GIC and fluoride-RB groups (p = .04).
In the GIC group, fewer new caries were observed in the unit of analysis respect to the other 2 groups. Incidence rate ratios (IRRs) were 0.70 (95% confidence interval: 0.50, 0.68; p <
.01) for GIC vs. RB and 0.79 (95% confidence interval: 0.53, 1.04; p = .005) for fluoride-RB vs. RB. Caries
incidence was significantly associated with low socioeconomic status
(IRR = 1.18; 95% confidence interval: 1.10, 1.42; p = .05). Dental sealant
high-viscosity GIC and fluoride-RB demonstrated protection against dental
caries, and there was evidence that these materials afforded additional protection for the tooth nearest to the
sealed tooth (clinical trial registration NCT01588210).