An in vitro evaluation of Icon resin infiltrant penetration into demineralized enamel lesions using an indirect staining technique with confocal laser scanning microscope analysis in dual fluorescence mode

J Conserv Dent Endod. 2024 Apr;27(4):366-372. doi: 10.4103/JCDE.JCDE_3_24. Epub 2024 Apr 5.

Abstract

Context: White spot lesion is the first clinical sign of a caries lesion and represents mineral loss from the enamel subsurface.

Aim: The aim of this study was to evaluate the penetration depth (PD) of Icon resin infiltrant into artificially demineralized enamel lesions using confocal laser scanning microscope (CLSM) analysis in dual fluorescence mode.

Settings and designs: The design of the study was an in vitro study.

Materials and methods: 22 extracted human permanent maxillary central incisor teeth were collected, and enamel sections were obtained from the coronal middle third. All enamel specimens were exposed to demineralization and remineralization solutions for 14 days. On positive confirmation of enamel demineralization by scanning electron microscope analysis, 20 specimens were then subjected to Icon resin infiltration following manufacturer instructions. Specimens were processed with indirect staining technique using rhodamine B and sodium fluorescein dyes and examined under CLSM at ×10 magnification in dual fluorescence mode using ImageJ software to evaluate PD of resin infiltrant into demineralized enamel lesions.

Statistical analysis used: Obtained data were analyzed using an independent t-test. P ≤0.05 was considered statistically significant.

Results: The maximum depth of demineralized enamel lesion was 590 μm, and the mean depth was 290.78 ± 14.80 μm. The maximum depth of resin infiltrant penetration was 580 μm, and the mean depth was 279.08 ± 13.88 μm; P = 0.006. The percentage penetration of resin infiltrant was 95.99%.

Conclusion: Icon resin infiltrant was highly effective in its depth of penetration into demineralized enamel lesions. The use of indirect staining and CLSM analysis in dual fluorescence mode is more reliable and accurate technique to evaluate the PD of resin infiltrant.

Keywords: Demineralized lesions; fluorescence; penetration depth; resin infiltrant.