This randomized controlled trial was a parallel arm 1-1 allocations. The study carried out in the Orthodontics Department, Izmir Katip Celebi University, Turkey. The protocol of the trial was approved by the Izmir Katip Celebi University Research Ethics Committee. A power analysis was carried out to provide that there was enough power to apply a statistical test of the research hypothesis to compare caries regression of Remin Pro to MI Paste Plus comparing with a control group in the remineralization of postorthodontic WSLs. Patients who finished their fixed appliance treatment in the clinic of the Department of Orthodontics, Faculty of Dentistry, Izmir Katip Celebi University who were found to comply with the study criteria were informed. Patients and parents who agreed to participate in the study signed an informed consent. A total of 39 people, 22 women and 17 men, aged between 14 and 23, were included in the study, with 13 people in each group. Gender distribution and average age of the groups are similar. Patients who are 12 to 25 years of age, at least had 12 months of orthodontic treatment with braces, at least had one upper anterior tooth with WSL included in the study. Patient who are smoking, with enamel hypoplasia or fluorosis, with active periodontal disease, with dentin caries, with allergy to casein, with previous bleaching excluded. Simple randomization was performed at the start of the study using a random number table prepared using SPSS software (version 26.0; New York, USA) for the allocation of patients who fulfilled all criteria and were willing to participate in this study. Group I: Patients were instructed to use MI Paste Plus (GC Europe, Leuven, Belgium) according to manufacturers instructions. Group II: Patients were instructed to use (Remin Pro, VOCO , Cuxhaven, Germany) a pea-sized amount of the cream. Group III. Patients (control group) used a 1450 ppm fluoridated tooth paste (Colgate Sensitive Pro-Relief, Colgate-Palmolive, Swidnica, Poland) for conventional tooth brushing and instructed to follow a routine home care. The patients were evaluated at baseline (T0) and every 30 days intervals for 3 months. The primary outcome measures were assessment of mineral loss based on fluorescence loss measurements using QLF. Lesions that scored 1 and 2 according to ICDAS II at debonding were included in the study. The buccal surfaces of the teeth were examined and evaluated by light induced fluorescence intraoral camera QLF-D Biluminator,™ (Inspektor-Pro, Amsterdam, Holland) for capturing fluorescent photographs in accordance with the manufacturer's instructions. Fluorescent images of the patient were evaluated in the 'White Spot Lesion' option of the analysis program (QA2.v.1.27). Following five QLF measurements were performed;

1. Depth of lesion (∆F, %) shows the percentage of loss in fluorescence.
2. Lesion area (LA, mm2) refers to the area covered by the demineralized area on the tooth.
3. Lesion volume (∆Q, % × mm2) is derived from the combination of lesion area and lesion depth and represents the volume of the affected enamel.
4. Maximum fluorescence loss (∆Fmax)is related to depth of lesion and mineral loss. Statistical analysis was performed with IBM® SPSS® (version 26. SPSS Inc., IBM Corporation, NewYork, USA). Descriptive statistics are expressed as number of units (n), percent (%), mean ± standard deviation (x ̅±ss), median (M), minimum (min), maximum (max), and interquartile range (IQR) values. The normal distribution of the data was evaluated with the Shapiro Wilk test of normality. Homogenicity of variances was evaluated with Levene's test.The concordance and differences in the first measurements and the second measurements were evaluated with the intra-class correlation coefficient and the paired samples t test. The ages of the groups were compared with one-way analysis of variance. The ΔF, lesion area and ΔFmax values of the groups in T0, T1, T2 and T3 were compared with two-way analysis of variance in repeated measurements. Bonferroni correction was applied in multiple comparisons. ΔQ, ICDAS II score, and difference values from baseline were compared between groups by Kruskal-Wallis analysis. In case of difference with Kruskal-Wallis analysis, Dunn-Bonferroni test was used for multiple comparisons. For ΔQ, ICDAS II score, Friedman analysis was performed for intragroup timepoint comparisons. Bonferroni correction was applied in multiple comparisons for Friedman analysis. Fisher Exact test was used to compare groups with categorical variables. If the chi-square test result was found to be significant, subgroup analyzes were performed with Bonferroni-corrected two-ratio z-test. Statistical significance level was set at p\<0.05.