Effect of Sodium Fluoride–Enhanced Orthodontic Wax (0.2% and 5%) on the Microhardness of White Spot Lesions in Demineralized Enamel: An in Vitro Study Publisher



Bahmani G ; Nouri A ; Masaebi F ; Yousefi A ; Nourian A
Source: International Orthodontics Published:2026

Abstract

Objective: To investigate the effect of enhanced orthodontic wax with 0.2% and 5% sodium fluoride on the microhardness of white spot lesions in demineralized enamel. Material and methods: In this experimental laboratory study, 30 extracted human premolar teeth were used. All samples were demineralized for 6hours in a demineralizing solution with a pH of 4. The samples were randomly divided into three groups of 10, treated as a control, the second group was treated with enhanced orthodontic wax with 0.2% NaF, and with enhanced orthodontic wax with 5% NaF. Then, all samples were immersed in artificial saliva for seven days. Using a Vickers microhardness tester, the hardness of the samples was measured before demineralization, after demineralization, and after remineralization. For statistical analysis Shapiro-Wilk test, paired sample t-test, one-way ANOVA test, followed by Tukey's post-hoc test, mixed-design repeated-measures ANOVA were used. The data were analysed using SPSS version 26 software. Results: After demineralization, no significant differences were observed among the groups regarding enamel microhardness (P-value>0.05), indicating that the samples in the three treatment groups and the control group exhibited similar microhardness levels. However, after the application of enhanced orthodontic wax containing sodium fluoride, a significant difference was found in the mean enamel microhardness before and after the intervention in the 0.2% group (P-value<0.05). Specifically, one week after the intervention with the 0.2% wax, the mean enamel microhardness significantly increased compared to the demineralized state. In contrast, there were no significant differences in the mean enamel hardness after the intervention within the other treatment groups. Conclusion: Enhanced orthodontic wax containing 0.2% sodium fluoride has the potential to remineralise white spot lesions and improve the microhardness of enamel. This finding is promising for future research and may provide a viable method for carious lesions during orthodontic treatment. © 2026 CEO. Published by Elsevier Masson SAS. All rights are reserved, including those for text and data mining, AI training, and similar technologies.