Fluoride-releasing sealant and caries-like enamel lesion formation in vitro.J Clin Pediatr Dent. 2000 Spring; 24(3):215-9.JC
The aim of this laboratory study was to evaluate the effects of a fluoride-releasing pit and fissure sealant (FS) and a conventional non-fluoride-containing pit and fissure sealant (CS) on caries-like lesion formation in enamel.
Twelve extracted, macroscopically caries-free human molar teeth underwent fluoride-free prophylaxis and were sectioned into toothquarters. Cavity preparations were placed in buccal and lingual surfaces of the toothquarters, acid-etched and filled with sealant material (per the manufacturer's instructions) as follows: 1) mesiobuccal and mesiolingual quarters--FS (Fissurit-F, VocoChemie); and 2) distobuccal and distolingual quarters--CS (Fissurit, VocoChemie). Prior to caries formation in an acidified gel, the toothquarters were thermocycled (500 cycles) in artificial saliva. Sections were taken following caries initiation (6 week gel exposure) and caries progression (9 week gel exposure), and examined by polarized light microscopy to determine mean primary surface lesion depth and presence or absence of wall lesions.
Mean surface lesion depths were significantly different between FS and CS groups following caries initiation (FS = 119 microns; CS = 157 microns, p < 0.05, paired t-test) and progression (FS = 169 microns; CS = 221 microns, p < 0.05, paired t-test). Wall lesions were reduced in FS (14% initiation; 25% progression) when compared with CS (19% initiation; 35% progression); however, this was not significantly different (p > 0.05, paired t-test).
A pit and fissure sealant containing releasable fluoride provided a caries inhibiting effect with a significant reduction in lesion depth in the surface enamel adjacent to the fluoride-releasing sealant and a tendency toward reduction in the frequency of wall lesions.
Fluoride release by pit and fissure sealants may provide additional protection against caries formation in cuspal incline enamel and smooth surfaces adjacent to sealed pits and fissures, and act as a fluoride reservoir with long-term release of fluoride into the immediately adjacent oral environment.