Comparison of Light-cured Pit and Fissure Sealants on Enamel Demineralization Using Swept-source Optical Coherence Tomography

Objectives: A swept source optical coherence tomography (SS-OCT) is a non-invasive, cross-sectional imaging system that can visualize the internal structures nondestructively. The SS-OCT is a useful tool to assess demineralization of enamel because reflectivity from enamel increases with demineralization.
The aim of this in vitro study was to compare light-cured pit and fissure sealant materials in terms of enamel demineralization using the SS-OCT.
Methods: Round cavities (1.5 mm diameter, 0.5 mm depth) were prepared on the bovine enamel blocks. Each cavity was filled with one of three light-cured resin sealants; non-fluoride containing Palfique Light Sealant (Tokuyama Dental), fluoride containing Teethmate F-1 2.0 (Kuraray Noritake Dental), and S-PRG filler containing BeautiSealant (Shofu). The outer enamel was polished with 2000-grit silicon carbide paper to remove the excess materials. B-scans images were obtained using SS-OCT (Santec) at 1310-nm center wavelength before and after demineralization (pH=4.5) for 5 days. An image analysis software was used to assess the demineralization of enamel surfaces.
Results: Palfique Light Sealant showed uniform demineralization on the enamel surfaces regardless of the distance from Palfique Light Sealant. On the other hand, Teethmate F-1 2.0 and BeautiSealant showed protective areas in adjacent enamel surfaces. Demineralization tended to progress with the distance from Teethmate F-1 2.0 and BeautiSealant.
Conclusions: Fluoride containing Teethmate F-1 2.0 and S-PRG filler containing BeautiSealant inhibited demineralization in adjacent enamel surfaces. The SS-OCT is an effective instrument to assess demineralization of enamel.