Incorporation of nano-hydroxyapatite into experimental resin infiltrant and its performance on color stability and reinforcement in demineralized enamel: in vitro study

Abstract

Abstract Objective The aim of the study was to evaluate the influence of the incorporation of 10% nano-hydroxyapatite into an experimental resin infiltranton color stability and cross-sectional microhardness.Material and methods 135 blocks were divided into five groups: H: healthy; MB: white spot; I: Icon®; E: experimental; EH: experimental containing 10% nano-hydroxyapatite. For color evaluation (n = 15), CIEL*a*b* values were obtained at the following time points: T0 (before immersion), T1 (14 days after immersion), and T2 (28 days after). Data were applied to CIEDE2000 formula. Cross-sectional microhardness (n = 12) data from the MB, I, E, and EH groups were applied to the mineral loss formula (∆S). Polarized Light Optical Microscopy images were obtained (n = 5) at 40x magnification. Shapiro-Wilk test was used to assess data normality for color stability and mineral loss. One-way ANOVA analysis was performed, followed by Bonferroni's post hoc test (color stability) and Tukey's test (mineral loss).Results In color stability results, regardless of time, there was no significant difference between H and MB groups; at 14 days and at 28 days, MB differed from all infiltrated groups, and H differed from E and EH. For ∆S, MB group showed a significant difference compared to I and EH groups but did not differ from E.Conclusion E and EH showcased similar performance to I regarding color variation. In terms of ∆S, I and EH had less mineral loss, suggesting a reinforcement of the dental structure.Clinical Relevance: Predict color stability and structural reinforcement of resinous infiltrants applied to white spot lesions.