Effects of Resin Infiltration on Orthodontic White-spot Lesions

Objectives: Objectives: 1. To determine if the resin infiltrant can improve the esthetic appearance of artificially induced white spot lesions (WSLs) by pH cycling on human extracted teeth. 2. To determine if the commercially available colorimeter can be used to monitor the shade changes of teeth throughout the demineralization and resin infiltration process.
Methods: Methods: Forty-two intact extracted human molars were divided into two groups: Control group (n=21) where teeth were stored in deionized water, and Experimental group (n=21) where teeth were exposed to Ten Cate demineralization solution (pH 4.26) and remineralization solution (pH=7) for 21 days to simulate white spot lesion formation during orthodontic treatment. All teeth were etched and resin-infiltrant (ICON, DMG) was applied in one layer (Application1) and two additional layers (Application2) following the manufacturer’s instructions. A colorimeter (Vita Easy Shade Advance 4.0, Vident) was used to measure the color of the teeth. L*a*b* values were recorded at baseline, after pH cycling, after Application1 and Application2. Color changes ∆E were calculated between each treatment for both the control and experimental groups. Data were analyzed using repeated measures analysis of variance (p< 0.05)
Results: Results: Comparing ∆E of the control to the experimental group revealed significant differences between the baseline and demineralized surfaces (5.07 vs 8.31)(p=0.02); after Application1 (5.08 vs 9.01, p=0.008) and after Application2 ( 6.07 vs 9.10, p=0.02) . When compared to the baseline, no significant differences were found between control and experimental group after Applications 1 or 2.
Conclusions: Conclusions: Vita easyshade colorimeter can be used to monitor the minor color changes of teeth during demineralization and resin-infiltration processes. Resin infiltrant may be used to improve the appearance of white spot lesion and restore it to the appearance of the original tooth.