Color properties of artificial white spot lesions treated by experimental resin infiltrants containing bioactive glass and nano-fluorohydroxyapatite

Aim: This study was conducted to assess the masking effects of some experimental resin infiltrants containing bioactive glass (BAG) and nano-fluorohydroxyapatite (n-FHAP) on enamel white spot lesions (WSLs). Materials and methods: Fifty enamel specimens were embedded in an acrylic resin and divided into five groups (n = 10). After creating artificial enamel lesions, the specimens were infiltrated by the following resins: 1) Group 1 (T/control group): TEG-DMA; 2) Group 2 (T2H): TEG-DMA + 2 wt% n-FHAP; 3) Group 3 (T5H): TEG-DMA + 5 wt% n-FHAP; Group 4 (T2B): TEG-DMA + 2 wt% BAG; Group 5 (T5B): TEG-DMA + 5 wt% BAG. Next, the specimens were subjected to demineralization–remineralization cycles for 2 weeks. Color assessments were performed by a spectrophotometer in four distinct stages: baseline, after the production of artificial caries, after resin infiltration, and 2 weeks after resin infiltration. L*, a*, b*, and ΔE values were calculated at each stage. Color parameters were analyzed statistically using the Kruskal-Wallis and Mann-Whitney U tests. The significance level was set at 5%. Results: All treatments led to a decrease in the L3* compared with the L2* value. The resin infiltrant containing 5% fluorohydroxyapatite (FHAP) exerted the highest L* reduction effect among all the groups. The T group was the only resin infiltrant group with a lower mean of a4* than those compared at baseline. Regarding the ΔE13* and ΔE14* values, only the resin infiltrants of groups 1 (T), 2 (T2H), and 3 (T5H) were able to mask artificial caries. Conclusion: Experimental resin infiltrants containing n-FHAP were able to mask WSLs after 14 days.