Effects of Pediatric Iron and Multivitamin Syrups on Invisalign First Aligners and the Efficacy of Cleaning Methods

Effects of Pediatric Iron and Multivitamin Syrups on Invisalign First Aligners and the Efficacy of Cleaning Methods | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Effects of Pediatric Iron and Multivitamin Syrups on Invisalign First Aligners and the Efficacy of Cleaning Methods Hasibe Elif Kuru, Muhammet Fidan, İbrahim Erhan Gelgör This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9226773/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 10 You are reading this latest preprint version Abstract This study evaluated the effects of pediatric iron- and multivitamin-containing syrups on the color stability and translucency of Invisalign First aligners and assessed the effectiveness of different cleaning protocols in reducing discoloration. Ninety-six specimens were divided into three solution groups (artificial saliva, iron syrup, and multivitamin syrup) and four cleaning subgroups (no cleaning, toothbrushing, cleaning tablets, and combined cleaning). The samples were immersed in the test solutions for 1 minute daily, followed by the assigned cleaning protocols, for one week. Color coordinates (L*, a*, b*) were measured using a spectrophotometer at baseline and after immersion, and color (ΔE00) and translucency (ΔRTP00) changes were calculated. Data were analyzed using generalized linear models (p < 0.05). Both solution type and cleaning protocol significantly affected color (p < 0.001), with iron syrup causing the greatest discoloration (ΔE00: 6.48 ± 1.87). Combined cleaning resulted in the lowest color change values. Translucency was also significantly reduced (p < 0.001), particularly in the iron syrup group (ΔRTP00: −5.89 ± 2.31). Pediatric syrups, especially iron-containing formulations, caused clinically perceptible discoloration and reduced translucency in clear aligners. Combined cleaning reduced discoloration, but measurable changes remained. Clinicians should advise removing aligners during syrup intake and maintaining appropriate cleaning routines to preserve aesthetics. Health sciences/Diseases Health sciences/Health care Health sciences/Medical research Cleaning protocols Clear aligners Color stability Pediatric patient Translucency Figures Figure 1 Introduction The transition from mixed dentition to permanent dentition is a critical growth period marked by significant orthodontic and orthopedic changes [ 1 ]. Early interceptive treatment during this phase is essential for guiding skeletal development and managing arch discrepancies, which usually involve fixed or removable expansion appliances [ 2 ]. Clear aligners, initially developed for adults, have increasingly been adapted for pediatric use because of their aesthetic benefits and clinical effectiveness in mild to moderate malocclusions. Invisalign First® (Align Technology, Santa Clara, CA, USA), introduced in 2018 [ 3 ], was specifically developed for mixed dentition, allowing controlled incremental tooth movement with sequential removable aligners tailored to growing jaws and erupting teeth [ 4 ]. Clinical evidence suggests that Invisalign first can effectively address mild arch deficiencies and contribute to dentoalveolar expansion, although treatment outcomes remain dependent on patient compliance [ 5 – 7 ]. Invisalign first is indicated during the mixed dentition phase, a period of rapid growth when children often need vitamin and mineral supplements. Pediatric syrups usually contain iron, vitamin C, B-complex vitamins, zinc, colourants, and acidic flavoring agents, many of which have a low pH and chromogenic potential [ 8 ]. Previous studies have shown that such liquid formulations can cause discoloration and changes in the translucency of resin-based restorative materials due to their acidic and staining components [ 9 , 10 ]. Patients are advised to drink only water while wearing aligners; however, they often consume pigmented drinks, which can change the polymer structure and decrease transparency [ 8 , 7 ]. Although each aligner is typically worn for a short time (one to two weeks), discoloration can still be clinically significant. Exposure to common beverages such as coffee, tea, red wine, soda, and other acidic drinks can significantly alter the chemical composition of clear aligners, potentially affecting patient motivation [ 11 , 12 ]. The evidence suggests that compliance with removable appliances in children may also be inconsistent, particularly regarding recommended daily wear time and adherence to professional instructions [ 6 , 7 ]. Some pediatric patients might wear aligners while drinking beverages or taking supplements, which can lead to staining. This discoloration can affect the appearance of the aligners and might make patients less willing to wear them as instructed, possibly impacting the success of the treatment. Additionally, although methods such as brushing and commercial aligner-cleaning tablets are advised for maintaining aligners, their effectiveness in removing residues or stains from pediatric medicinal syrups remains uncertain. To the authors’ knowledge, no prior research has examined how pediatric medicinal syrups affect the optical properties of Invisalign First aligner materials or compared different cleaning methods for eliminating these residues. Therefore, the aims of this in vitro study were i) to evaluate the effects of iron and multivitamin pediatric syrups on the color stability and translucency of Invisalign First aligner material and ii) to assess the cleaning efficacy of different maintenance protocols (toothbrushing, cleaning tablets, and their combined use in removing syrup-induced discoloration and residues from aligners). The null hypotheses tested were as follows: i) exposure to iron and multivitamin syrups would not cause significant changes in the color or translucency of the Invisalign First aligner material; and (ii) there would be no difference among the evaluated cleaning protocols (toothbrushing, cleaning tablets, and the combined use of both methods) in their ability to remove syrup-induced discoloration and residues from the aligners. Materials and methods As this was an in vitro study using commercially available materials and no human or animal subjects were involved, ethical approval was not needed. Study design and sample size A power analysis was performed for a two-way factorial design via G*Power software (version 3.1.9.7; Heinrich-Heine University, Düsseldorf, Germany). Assuming a 95% confidence level (α = 0.05), 85% statistical power (1–β = 0.85), and an effect size of f = 0.25, the minimum required sample size was calculated as 90 samples [ 13 ]. Based on this calculation, eight samples were allocated to each subgroup, resulting in a total of 96 samples across 12 subgroups included in the study. Specimen preparation Specimen preparation Invisalign First® (Align Technology, Santa Clara, CA, USA) was fabricated from a mixed‑dentition digital model according to the manufacturer’s protocols. Standardization targeted the maxillary central incisor (tooth #11) region. The samples were divided into three main groups, each further subdivided into four subgroups according to the cleaning protocol applied. The main groups were defined as follows: Group 1: Control group (artificial saliva exposure) Group 2: Iron syrup exposure Group 3: Multivitamin syrup exposure Each group was further divided into four subgroups: Subgroup A: No cleaning protocol was applied Subgroup B: Toothbrushing only Subgroup C: Cleaning tablet only Subgroup D: Combinations of toothbrushing and cleaning tablets The detailed distribution and workflow of the experimental groups are presented in Fig. 1 . Solutions and exposure protocol Preexperiment measurements of color and translucency were conducted as described below. For the iron exposure group, 5 mL of Ferro Sanol B pediatric syrup was used. Each 5 mL dose provides 112.5 mg of iron(II)-glycine sulfate complex, equivalent to 20 mg of Fe²⁺. It also contains 0.43 mg of riboflavin-5-sodium phosphate, 0.32 mg of vitamin B1 (thiamine hydrochloride), and 0.63 mg of vitamin B6 (pyridoxine hydrochloride). The formulation also includes excipients such as ascorbic acid, refined sugar, glucose monohydrate, sorbitol, sulfuric acid (95–98%), orange flavor, pear flavor, and deionized water. In Group 1, the samples were stored in artificial saliva (sodium chloride (0.4 g/l), potassium chloride (0.4 g/l), calcium chloride·H2O (0.795 g/l), sodium dihydrogen phosphate·H2O (0.69 g/l), sodium sulfur·9H2O (0.005 g/l), and 1000 mL distilled water) for one week [ 9 ]. For the multivitamin exposure group, Argivit Immun-C syrup was used. The formulation contained deionized water, sorbitol, glycerol, black elderberry extract (250 mg per dose), L-ascorbic acid (vitamin C; 250 mg), zinc gluconate (5 mg), quercetin (50 mg), lactoferrin (25 mg), grape seed extract (5 mg), sodium carboxymethyl cellulose, polysorbate 80, potassium sorbate, xanthan gum, sucralose, sodium selenite (50 µg), and mixed flavoring agents. In Groups 2 and 3, each aligner specimen was immersed in 5 mL of undiluted pediatric syrup placed in a test tube. The samples were agitated for 1 min daily, and both the buccal and palatal surfaces were gently agitated via an applicator to ensure contact of the solution with the inner and outer surfaces of the aligner material. This procedure was intended to simulate daily oral exposure of clear aligners to pediatric liquid supplements [ 9 ]. After immersion, the cleaning protocols were applied according to the subgroup allocation. Cleaning protocols Subgroup A: Specimens were rinsed with distilled water for 5 seconds. Subgroup B (Mechanical cleaning): Specimens were cleaned once daily with an electric toothbrush in continuous mode (Oral-B Genius Pro 9000; Braun, Melsungen, Germany). Brushing was performed once daily for 30 seconds using a pea-sized amount of toothpaste (Sensodyne Clinical Repair; Haleon, Weybridge, United Kingdom), and the samples were subsequently rinsed with warm water for 5 seconds, following the manufacturer’s aligner cleaning recommendations [ 14 , 15 ]. Subgroup C (chemical cleaning): Specimens were immersed in glass water at room temperature to prevent potential deformation of the aligner material. A Corega BioFormula cleaning tablet (Stafford-Miller, Dungarvan, Co. Waterford, Ireland) was dissolved in the water, and each sample was immersed in the solution for 5 minutes daily, followed by rinsing with distilled water for 5 seconds [ 14 ]. Subgroup D (Mechanical + Chemical cleaning): The samples were first cleaned via the toothbrushing protocol described above and then immersed in the cleaning tablet solution, and both methods were applied sequentially. The immersion and cleaning procedures were repeated daily for one week, simulating the typical wear period of a single Invisalign First aligner, which is approximately one week before replacement with the next aligner in the treatment sequence. Between immersion periods, the samples were stored in distilled water. Procedure for measurement of color values The color values (L, a, b) of the aligners were measured on a white background (L = 96, a = 0, b = 1) and black background (L = 8, a = 1, b=-1) (GC3; Danes Picta) via a spectrophotometer (VITA Easyshade V, VITA Zahnfabrik, Bad Säckingen, Germany). The “L” parameter represents lightness, the “a” parameter represents the color coordinates between red (+) and green (-), and the “b” parameter represents the color coordinates between yellow (+) and blue (-). Measurements were performed under D65 conditions [ 16 ]. Color measurements were performed via a spectrophotometer calibrated according to the manufacturer's instructions. A probe tip with a diameter of 5 mm was placed at the center of each sample. A silicone matrix was prepared to standardize the color measurement area and was used as a template. A circular window with a diameter of 6 mm was created in the silicone matrix via a circular cutter, and the aperture was placed in the middle third of the buccal surface to ensure consistent measurement. Each sample was measured three times, and the average value of these measurements was recorded. Color coordinates (L*, a*, b*) were obtained at two time points: baseline (T0) and after immersion in the solutions (T1). Determination of color change values The color change (ΔE00) values were calculated on the basis of white background data. Three measurements were taken for each sample, and their average was used as the representative color value. The color change values were calculated via the CIEDE2000 color difference formula in the T0–T1 time interval [ 17 ]: where Δ L’ , Δ C’ , and Δ H’ represent the variations in lightness, chroma, and hue between the two samples, respectively. Weighting functions ( S L, S C, and S H) are used to modify the total color difference on the basis of the location of the color difference pair within the L, a, and b values. The parametric factors ( K L, K C, and K H) function as correction terms for the experimental settings, with values set at 1:1:1 in the current research. The rotation factor (RT) defines the relationship between color and hue variations in the blue spectrum [ 18 ]. Metric discontinuities due to mean hue computation and hue difference computation were considered in the ΔE00 calculation [ 19 ]. All values of the color differences were clinically interpreted by comparison with their respective 50:50% thresholds for perceptibility (PT00) and acceptability (AT00), which were determined in the literature [ 20 ] and recommended by the Technical Report ISO/TR 28642:2016 [ 21 ]. In this study, ΔE00 differences were evaluated using thresholds of 50%:50% perceptibility (PT: 0.8 ΔE00) and 50%:50% acceptability (AT: 1.8 ΔE00) [ 17 ]. Determination of relative translucency parameter values Color values were measured on both black and white backgrounds. Relative translucency parameter (RTP) values were recorded at T0 and T1. The formula CIEDE2000 (1:1:1:1) was used to calculate the RTP00 values. The RTP00 of each sample was calculated via the following formula [ 22 ]: “B” and ‘W’ denote the lightness (L’), chroma (C’), and hue (H') of the samples against black and white backgrounds, respectively. Weighting functions (SL, SC, and SH) are used to modify the total color difference on the basis of the location of the color difference pair within the L, a, and b color space. The parametric factors (KL, KC and KH) serve as correction terms for the experimental settings, and in this investigation, RTP00 (1:1:1) values were used. The rotation factor (RT) defines the relationship between color and hue variations in the blue spectrum [ 22 , 23 ]. The translucency value indicates the degree of translucency of the material and ranges from 0–100; values closer to 0 indicate lower translucency, whereas values closer to 100 indicate higher translucency. In this study, ΔTP00 differences were evaluated using thresholds of 50%:50% perceptibility (TPT: 0.62 ΔTP00) and 50%:50% acceptability (TAT: 2.62 ΔTP00). The ranges for the ΔRTP00 values were determined as T0–T1. The perceptibility threshold for the relative translucency parameter difference (ΔRTP00) was set at 0.62, whereas the acceptability threshold was set at 2.62 [ 22 ]. Statistical analysis The data obtained were analyzed with IBM SPSS V27 (IBM, Armonk, NY, USA). The normality of the data distribution was assessed via the Kolmogorov–Smirnov test, and the homogeneity of variance was evaluated via Levene’s test. As a result, parametric tests were performed for the statistical analysis. The ΔE00 and ΔRTP00 values were evaluated via generalized linear model (GLM; two-way model) analysis (solution, cleaning method, and solution × cleaning method). RTP00 values were evaluated via generalized linear model (GLM) three-way analysis (solution, cleaning method, time and interactions). The dependent variables were continuously measured and modeled under a normal distribution. When significant main or interaction effects were detected, pairwise comparisons were performed via Bonferroni correction. The results are presented as the means ± standard deviations. The significance level was set at p < 0.05. Results Color change (ΔE00) results The GLM results for ΔE00 are presented in Table 1 . The GLM results for color change (ΔE00) revealed that the main effects of the solution and cleaning methods were statistically significant (p < 0.001) (Table 2 ). The means and standard deviations of the ΔE00 values for all the groups are presented in Table 2 . When the solutions were compared, the greatest color change was observed in the iron supplement group (6.48 ± 1.87) (p < 0.001). The lowest value was found in the artificial saliva (control) group (3.01 ± 1.18). Among the cleaning methods, the noncleaned group presented the greatest color change (5.75 ± 2.39) (p < 0.001). The mechanical (4.79 ± 2.06) and chemical (4.81 ± 2.19) cleaning methods presented similar ΔE00 values. The lowest color change was observed in the combined mechanical + chemical cleaning group (3.80 ± 1.69) (p < 0.05) (Table 2 ). Table 1 GLM results for color change and translucency change *Generalized linear models Color change Wald Chi-Square df p* Intercept 1036.392 1 < 0.001 Solution 90.864 2 < 0.001 Method 21.525 3 < 0.001 Solution * Method 4.632 6 0.592 Translucency change Wald Chi-Square df p* Intercept 167.193 1 < 0.001 Solution 68.111 2 < 0.001 Method 4.207 3 0.240 Solution * Method 5.711 6 0.456 Table 2 Differences of color change values between the groups Materials Solutions Artificial saliva Iron supplement Multivitamin Total mean Noncleaned 3.39 ± 1.52 8.07 ± 1.33 5.80 ± 1.46 5.75 ± 2.39a Mechanical 3.11 ± 1.37 6.26 ± 1.96 4.99 ± 1.59 4.79 ± 2.06b Chemical 3.03 ± 1.05 6.53 ± 1.91 4.87 ± 2.02 4.81 ± 2.19b Mechanical + Chemical 2.51 ± 0.61 5.08 ± 1.03 3.80 ± 2.06 3.80 ± 1.69c Total mean 3.01 ± 1.18A 6.48 ± 1.87B 4.86 ± 1.86C 4.79 ± 2.18 mean±standard deviation a-c There is no difference between methods with the same letter in the same column. A-C There is no difference between solutions with the same letter in the row. Translucency change (ΔRTP00) results For the RTP change (ΔRTP), GLM analysis demonstrated that the main effect of solution was statistically significant (p < 0.001) (Table 1 ). The greatest decrease in RTP00 was observed in the iron supplement group (-5.89 ± 2.31) (p < 0.001). The lowest decrease in RTP00 was observed in the artificial saliva group (-0.44 ± 3.97) (p < 0.001) (Table 3 ). Table 3 Differences of translucency change values between the groups Materials Solutions Artificial saliva Iron supplement Multivitamin Total mean Noncleaned -0.03 ± 3.09 -7.92 ± 1.81 -5.67 ± 1.52 -4.54 ± 4.01 Mechanical -0.62 ± 4.76 -6.05 ± 2.54 -3.77 ± 2.12 -3.48 ± 3.92 Chemical -0.61 ± 3.43 -5.15 ± 1.67 -4.73 ± 2.61 -3.50 ± 3.30 Mechanical + Chemical -0.50 ± 5.04 -4.41 ± 1.84 -3.96 ± 2.06 -2.96 ± 3.64 Total mean -0.44 ± 3.97A -5.89 ± 2.31B -4.53 ± 2.15C -3.62 ± 3.71 means±standard deviations. A-B There is no difference between solutions with the same letter in the row. For the time-dependent RTP values, the main effects of solution (p < 0.001), method (p = 0.033), and time (p < 0.001) were statistically significant. Additionally, the solution × time interaction was significant (p < 0.001) (Table 4 ). The lowest RTP values were observed in the iron supplement × baseline (t0) interaction (32.78 ± 1.98) (p < 0.001) (Table 5 ). Table 4 GLM results for RTP values before and after immersion in solutions Source Wald Chi-Square df p* Intercept 44484.518 1 < 0.001 Solution 14.295 2 < 0.001 Method 8.731 3 0.033 Time 159.448 1 < 0.001 Solution * Method 5.721 6 0.455 Solution * Time 64.956 2 < 0.001 Method * Time 4.013 3 0.260 Solution * Method * Time 5.446 6 0.488 *Generalized linear models Table 5 Descriptive statistics for RTP values before (T0) and after immersion (T1) Time Solution Methods Baseline (t0) After immersed (t1) Total Artificial saliva Noncleaned 31.03 ± 2.64 30.99 ± 2.68 31.01 ± 2.57 Mechanical 31.84 ± 2.39 31.21 ± 3.09 31.53 ± 2.69 Chemical 31.02 ± 2.09 30.40 ± 2.58 30.71 ± 2.29 Mechanical + Chemical 31.15 ± 1.96 30.65 ± 4.00 30.90 ± 3.05 Total 31.26 ± 2.20ef 30.81 ± 3.00f 31.04 ± 2.62X Iron supplement Noncleaned 33.22 ± 2.22 25.29 ± 1.49 29.25 ± 4.48 Mechanical 33.80 ± 2.28 27.74 ± 2.01 30.77 ± 3.75 Chemical 31.37 ± 1.10 26.21 ± 1.35 28.79 ± 2.91 Mechanical + Chemical 32.74 ± 1.54 28.32 ± 1.44 30.53 ± 2.70 Total 32.78 ± 1.98c 26.89 ± 1.94bd 29.84 ± 3.55Y Multivitamin Noncleaned 32.40 ± 0.90 26.73 ± 1.57 29.57 ± 3.18 Mechanical 31.85 ± 2.11 28.07 ± 1.39 29.96 ± 2.60 Chemical 32.16 ± 1.99 27.43 ± 2.19 29.80 ± 3.17 Mechanical + Chemical 32.44 ± 1.54 28.47 ± 1.78 30.45 ± 2.60 Total 32.21 ± 1.64ace 27.68 ± 1.80b 29.94 ± 2.85Y Total Noncleaned 32.22 ± 2.17 27.67 ± 3.12 29.94 ± 3.51ADC Mechanical 32.49 ± 2.36 29.01 ± 2.69 30.75 ± 3.06BE Chemical 31.52 ± 1.77 28.01 ± 2.70 29.77 ± 2.87C Mechanical + Chemical 32.11 ± 1.76 29.15 ± 2.77 30.63 ± 2.74DE Total 32.09 ± 2.03x 28.46 ± 2.85y 30.27 ± 3.08 mean±standard deviation; A-E There is no difference between methods with the same letter in the same column. X-Y There is no difference between solutions with the same letter in the column. x-y There is no difference between times with the same letter in the row. a-f There is no difference between interactions (solution × time) with the same letter. The total values represent the means obtained from GLM analyses and are provided to show the data for the main effects and interaction values; the inferential results are based on GLM tests. Discussion In this study, the effects of pediatric iron and multivitamin syrups on the optical properties of Invisalign First orthodontic aligners were evaluated, and the effectiveness of different cleaning protocols in reducing syrup-induced discoloration was examined. The findings showed that exposure to pediatric medicinal syrups significantly affected both the color stability and translucency of the aligner material. Among the tested solutions, the iron-containing syrup produced the greatest color change and the most pronounced reduction in translucency, whereas the combined mechanical and chemical cleaning protocol yielded the lowest color change values. Accordingly, both null hypotheses were rejected. The discoloration observed in the iron syrup group can be explained by both chemical and material-related mechanisms. Iron-containing formulations may promote the formation of dark complexes and enhance pigment deposition on material surfaces. In addition, pediatric syrups often contain chromogenic agents, acidic components, and viscous excipients that prolong the contact time and facilitate stain adsorption [ 8 – 10 ]. From a materials perspective, Invisalign First aligners are fabricated from 0.75 mm-thick thermoplastic polyurethane with a heterogeneous polymer network that may allow diffusion of staining molecules into the matrix [ 24 ]. Exposure to low-pH solutions may further induce surface softening, increasing susceptibility to pigment penetration and retention [ 4 , 25 ]. The lower color change observed in the multivitamin syrup group than in the iron syrup group can be explained by differences in chromogenic composition and metal ion content. Iron-containing formulations can undergo oxidation reactions and form dark-colored metal complexes that increase pigment accumulation and staining on polymer surfaces [ 26 ]. In contrast, multivitamin syrups primarily contain organic pigments and vitamins with lower chromogenic potential, which leads to a reduced color change. The staining and oxidation processes caused by metal ions increase color changes in dental materials by promoting pigment adsorption and chemical interactions with the polymer matrix. Furthermore, previous studies on transparent dental restoratives have shown that the staining intensity depends on the chemical composition and chromogenic potential of the immersion solution, which supports the current findings [ 27 ]. These findings are consistent with previous studies demonstrating that pediatric liquid medications can adversely affect the color stability of dental materials. Tüzüner et al. reported that iron-containing pediatric drugs caused the greatest discoloration among the tested formulations, whereas other studies have shown that multivitamin syrups and similar liquid supplements can also induce clinically perceptible color changes due to their chromogenic and acidic composition [ 9 , 10 ]. In addition, studies on clear aligners have demonstrated that thermoplastic orthodontic materials are susceptible to staining when exposed to pigmented beverages such as coffee and tea, supporting the present results [ 11 , 12 ]. In addition to color changes, a significant reduction in translucency was observed, particularly in the iron syrup group. The optical properties of materials are closely related to light transmission, absorption, and scattering. Materials with higher light transmittance appear more transparent, whereas increased absorption and pigment penetration may reduce transparency [ 28 ]. Our results may be explained by the adsorption of pigments onto the polymer surface or by microstructural alterations occurring within the material. Furthermore, the observed decrease in RTP00 values after one week of exposure suggests that contact with artificial saliva and minor surface changes over time may also influence translucency [ 28 ]. However, the magnitude of the observed translucency changes remained below clinically acceptable thresholds. Since one of the main advantages of clear orthodontic appliances is their aesthetic invisibility, maintaining translucency is an important factor for patient satisfaction [ 29 ]. The findings of the present study indicate that appropriate cleaning protocols may contribute to preserving the aesthetic properties of clear aligners. In the clinic, orthodontists should consider the potential staining effects of liquid medications used in pediatric patients and provide guidance on appropriate cleaning protocols. In this study, combining mechanical and chemical cleaning methods resulted in the least color change, which aligns with existing research that suggests that such combined approaches are more effective for cleaning orthodontic appliances. The superior performance of the combined protocol may be explained by its dual mechanism of action: mechanical brushing disrupts and removes loosely bound surface deposits, whereas chemical cleaning products, such as effervescent tablets, facilitate the dissolution of organic residues and promote the breakdown of pigment complexes adhering to the material surface. This complementary effect enhances cleaning efficacy by removing both superficial and strongly attached stains. Chang et al. reported that this combination effectively reduces staining and maintains the translucency of Essix retainers [ 29 ]. Similarly, Wible et al. reported that long-term cleaning can significantly impact the color and surface quality of copolyester retainers [ 30 ]. Several other studies [ 31 – 34 ] support the effectiveness of denture-cleaning tablets and specialized solutions in minimizing staining, although some agents may negatively affect material properties after extended use [ 35 ]. Consequently, consistent and thorough cleaning is crucial to prevent biofilm buildup and pigment deposits during prolonged aligner wear [ 36 ]. Clear aligners are increasingly preferred in orthodontic treatment because of their aesthetic advantages and patient comfort. Therefore, maintaining the transparency and color stability of the material throughout treatment is of clinical importance. Color changes may negatively affect the aesthetic appearance of the appliance, particularly in the anterior region, where visibility is highest, potentially reducing patient satisfaction and treatment compliance [ 37 ]. In the present study, all color measurements were performed on the buccal surfaces of the maxillary anterior teeth, as this region is the most clinically visible region during speech and smiling, thereby providing a more relevant and sensitive assessment of optical changes under real-life conditions [ 38 ]. This study has several key strengths. One of the few studies that have explored how pediatric medicinal syrups affect the optical properties of Invisalign First aligner materials is the addition of new data to the field. Additionally, assessing both color stability and translucency at the same time provides a more complete picture of aesthetic changes. Notably, this study introduces a clinically relevant and less explored method by focusing on staining agents routinely prescribed to pediatric patients instead of more optional consumables such as coffee or tea. This approach offers a more realistic clinical context and broadens the understanding of staining in clear aligners. Moreover, comparing different cleaning protocols provides useful insights into effective ways to maintain the aesthetic quality of aligners in everyday use. The 1-minute daily immersion protocol used in this study simulates the short but repeated exposure of clear aligners to pediatric syrups under clinical conditions. In routine practice, pediatric syrups are typically consumed quickly and do not remain in the mouth for long, whereas aligners are worn continuously for approximately 1–2 weeks. This causes repeated exposure to staining agents, and even brief contact with chromogenic solutions can accumulate over time, leading to noticeable optical changes. Similar to this study, previous in vitro research on aligner staining used time-controlled immersion protocols to mimic real-life exposure to beverages and solutions during aligner wear, supporting the clinical importance of these models [ 9 , 10 , 31 , 39 ]. Several limitations of this study should be acknowledged. First, the experimental conditions were conducted in vitro and may not fully reflect the complex oral environment, where factors such as saliva, temperature changes, and mechanical wear can influence material behavior. Second, the immersion protocol simulated short-term daily exposure rather than continuous intraoral conditions. Third, only two types of pediatric medicinal syrups have been evaluated, and different formulations may have varying effects on aligner materials. Future studies should include a wider range of pediatric medications, longer exposure periods, and additional factors, such as salivary components, to better simulate clinical conditions. Despite these limitations, this study provides clinically relevant information on the effects of pediatric medicinal syrups on clear aligners and highlights the importance of appropriate cleaning strategies in daily practice. Understanding these interactions is important for improving patient education and aligner maintenance strategies. Clinicians should inform patients and caregivers about the potential staining effects of pediatric syrups and emphasize the importance of removing aligners before intake and following appropriate cleaning procedures. Conclusions Within the limitations of this in vitro study, the following conclusions can be drawn: Pediatric iron and multivitamin syrups cause significant optical changes in Invisalign First aligners, with iron formulations producing the greatest discoloration and translucency loss. Combined mechanical–chemical cleaning (toothbrushing plus cleaning tablets) reduces syrup‑induced discoloration more effectively than single‑method protocols do but cannot fully restore the original optical properties. Clinicians should advise families to remove aligners before syrup intake and to adopt combined daily cleaning routines to preserve aesthetics and support treatment compliance. Declarations Conflicts of interest: The authors declare that they have no conflicts of interest related to this work. Funding: This research received no external funding and was conducted without any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Author Contribution E.K.: Conceptualisation, methodology, investigation, data acquisition, and writing—original draft. M.F.: Methodology, data collection, formal analysis, and writing—original draft. I.E.G.: Conceptualisation, methodology, writing—original draft, review and editing, and supervision. Data Availability The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. References Martins, M., Costa, C., Abrão, J. & Borri, M. Expansão rápida da maxila: análise da densidade radiográfica da sutura palatina mediana e sua correlação nos estágios de neoformação óssea, por meio de imagem digitalizada. Rev Dent. Press. Ortod E Ortop. Facial 14 , (2009). Gonçalves, A., Ayache, S., Monteiro, F., Silva, F. S. & Pinho, T. Efficiency of Invisalign First® to promote expansion movement in mixed dentition: a retrospective study and systematic review. Eur. J. Paediatr. Dent. 24 , 112–123 (2023). Kalaoglu, E. E. & Dumanli Gok, G. 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Evaluation of the Upper Arch Morphological Changes after Two Different Protocols of Expansion in Early Mixed Dentition: Rapid Maxillary Expansion and Invisalign(®) First System. Life (Basel Switzerland ) 12 , (2022). Elkhodary, H. et al. The impact of long-term use of pediatric liquid medications on primary tooth enamel: an in vitro study. J. Clin. Pediatr. Dent. 49 , 119–128 (2025). Tüzüner, T. et al. Effects of Different Pediatric Drugs on the Color Stability of Various Restorative Materials Applicable in Pediatric Dentistry. Biomed Res. Int. 9684193 (2017). (2017). Aktaş, N., Akın, Y., Bal, C. & Bani, M. & Bankoğlu Güngör, M. Effect of the Different Dietary Supplements on the Average Surface Roughness and Color Stability of Direct Restorative Materials Used in Pediatric Dentistry. Child (Basel Switzerland ) 11 , (2024). Perumalla, B. P. et al. Assessing colour stability of direct printed and thermoformed aligners: An in vitro study on aesthetics longevity. Int. Orthod. 24 , 101105 (2026). Tsomos, G., Ludwig, B., Grossen, J., Pazera, P. & Gkantidis, N. Objective assessment of patient compliance with removable orthodontic appliances: a cross-sectional cohort study. Angle Orthod. 84 , 56–61 (2014). Cohen, J. Statistical power analysis for the behavioral sciences (Routledge, 2013). Šimunović, L. et al. Impact of various cleaning protocols on the physical and aesthetic properties of 3D-printed orthodontic aligners. Sci. Rep. 15 , 19022 (2025). 7 simple tips to help you maintain your Invisalign clear aligners. (2022). Available at: https://www.invisalign.co.uk/resources/care/7-simple-tips-to-help-you-maintain-your-invisalign-clear-aligners Yılmaz Savaş, T. & Akın, C. Effects of sintering protocol and dipping time on the optical properties of monolithic zirconia. J. Prosthet. Dent. 127, 801.e1-801.e8 (2022). Paravina, R. D. et al. Color Difference Thresholds in Dentistry. J. Esthet Restor. Dent. 27 , S1–S9 (2015). Castillo Peña, R. et al. Effect of polishing and bleaching on color, whiteness, and translucency of CAD/CAM monolithic materials. J Esthet Restor. Dent 37 , (2024). Sharma, G., Wu, W. & Dalal, E. N. The CIEDE2000 color-difference formula: Implementation notes, supplementary test data, and mathematical observations. Color. Res. Appl. 30 , 21–30 (2005). Paravina, R. D., Pérez, M. M. & Ghinea, R. Acceptability and perceptibility thresholds in dentistry: A comprehensive review of clinical and research applications. J. Esthet. Restor. Dent. Off. Publ. Am. Acad. Esthet. Dent. … et al.] 31, 103–112 (2019). ISO/TR 28642:2016 Dentistry. Guidance on colour measurement. March (2026). Available at: https://www.iso.org/standard/69046.html . (Accessed: 5th. Ghanem, R., Adel, A. & Al-Zordk, W. Effect of simulated intraoral adjustment on the color and translucency of gradient multilayered monolithic zirconia. J. Prosthet. Dent. 132, 1313.e1-1313.e8 (2024). Salas, M. et al. Translucency thresholds for dental materials. Dent. Mater. 34 , 1168–1174 (2018). Bichu, Y. M. et al. Advances in orthodontic clear aligner materials. Bioact Mater. 22 , 384–403 (2023). Houle, J. P., Piedade, L., Todescan, R. J. & Pinheiro, F. H. S. L. The predictability of transverse changes with Invisalign. Angle Orthod. 87 , 19–24 (2017). Asgari, I., Soltani, S. & Sadeghi, S. M. Effects of Iron Products on Decay, Tooth Microhardness, and Dental Discoloration: A Systematic Review. Arch. Pharm. Pract. 11 , 60–72 (2020). Olteanu, N. D. et al. Color Stability of Various Orthodontic Clear Aligner Systems after Submersion in Different Staining Beverages. Materials 17 , 4009 (2024). Cremonini, F., Vianello, M., Bianchi, A. & Lombardo, L. A Spectrophotometry Evaluation of Clear Aligners Transparency: Comparison of 3D-Printers and Thermoforming Disks in Different Combinations. Appl. Sci. 12 , 11964 (2022). Chang, C. S., Al-Awadi, S., Ready, D. & Noar, J. An assessment of the effectiveness of mechanical and chemical cleaning of Essix orthodontic retainer. J. Orthod. 41 , 110–117 (2014). Wible, E. et al. Long-term effects of different cleaning methods on copolyester retainer properties. Angle Orthod. 89 , 221–227 (2019). Ajwa, N., Radhi, F., Aloraini, R. & AlSaydalani, G. Comparative color stability assessment of orthodontic clear aligners: an in vitro study. Sci. Rep. 15 , 2041 (2025). Alweneen, A. & Alqahtani, N. The Effectiveness of Different Cleaning Methods for Clear Orthodontic Aligners: Impacts on Physical, Mechanical, and Chemical Properties-An In Vivo Study. Polymers (Basel) 17 , (2025). Bernard, G., Rompré, P., Tavares, J. R. & Montpetit, A. Colorimetric and spectrophotometric measurements of orthodontic thermoplastic aligners exposed to various staining sources and cleaning methods. Head Face Med. 16 , 2 (2020). Kılıç, B., Canpolat, Ş. & Öztürk, M. Comparative evaluation of the effect of different cleaning agents on colour and surface roughness of Invisalign clear aligners: a cross-over randomized controlled trial. BMC Oral Health . 25 , 1745 (2025). Nayak, M. et al. A comparative evaluation of efficacy of 4 different disinfectant solutions on clear aligner translucency: An In-Vitro study. Int J. Multidiscip Res 7 , (2025). Gardner, G. D., Dunn, W. J. & Taloumis, L. Wear comparison of thermoplastic materials used for orthodontic retainers. Am. J. Orthod. Dentofac. Orthop. Off Publ Am. Assoc. Orthod. its Const. Soc. Am. Board. Orthod. 124 , 294–297 (2003). Liu, C. L. et al. Colour stabilities of three types of orthodontic clear aligners exposed to staining agents. Int. J. Oral Sci. 8 , 246–253 (2016). Fidan, M. & Gelgor, I. E. Effect of aging and mechanical brushing on color stability and translucency of three-dimensionally printed and thermoformed aligners of different thicknesses. Angle Orthod. 96 , 83–92 (2025). Kobkiatkawin, C., Panyayong, W., Suphangul, S. & Thiradilok, S. Color stability of clear aligners exposed to various beverages: an in vitro study. BMC Oral Health . 25 , 971 (2025). Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Revision Version 1 posted Reviews received at journal 26 Apr, 2026 Reviewers agreed at journal 26 Apr, 2026 Reviews received at journal 23 Apr, 2026 Reviewers agreed at journal 19 Apr, 2026 Reviewers agreed at journal 19 Apr, 2026 Reviewers invited by journal 19 Apr, 2026 Editor assigned by journal 16 Apr, 2026 Editor invited by journal 31 Mar, 2026 Submission checks completed at journal 29 Mar, 2026 First submitted to journal 29 Mar, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9226773","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":629737160,"identity":"730c7456-aa33-4e29-ba7e-e82438cbaf59","order_by":0,"name":"Hasibe Elif Kuru","email":"","orcid":"","institution":"Usak University School of Dentistry","correspondingAuthor":false,"prefix":"","firstName":"Hasibe","middleName":"Elif","lastName":"Kuru","suffix":""},{"id":629737161,"identity":"f805a91b-0d13-407f-bb22-06796f9feca4","order_by":1,"name":"Muhammet Fidan","email":"","orcid":"","institution":"Usak University School of Dentistry","correspondingAuthor":false,"prefix":"","firstName":"Muhammet","middleName":"","lastName":"Fidan","suffix":""},{"id":629737162,"identity":"73cfd641-ba29-44c1-90ab-597370551020","order_by":2,"name":"İbrahim Erhan Gelgör","email":"data:image/png;base64,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","orcid":"","institution":"Usak University School of Dentistry","correspondingAuthor":true,"prefix":"","firstName":"İbrahim","middleName":"Erhan","lastName":"Gelgör","suffix":""}],"badges":[],"createdAt":"2026-03-25 19:53:29","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9226773/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9226773/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":107896283,"identity":"a27e15f2-36ba-46a8-a489-5c7e7affdee3","added_by":"auto","created_at":"2026-04-27 10:52:54","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":64093,"visible":true,"origin":"","legend":"\u003cp\u003eFlow chart of the study design.\u003c/p\u003e","description":"","filename":"Figure1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-9226773/v1/aee6a4854334c9bbd80ccf7a.jpeg"},{"id":108006687,"identity":"61ceccfe-a52f-4b08-b7fa-218e8c29653a","added_by":"auto","created_at":"2026-04-28 12:56:28","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":495819,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9226773/v1/18405505-0527-42ea-8c97-f09cec645cdc.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Effects of Pediatric Iron and Multivitamin Syrups on Invisalign First Aligners and the Efficacy of Cleaning Methods","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe transition from mixed dentition to permanent dentition is a critical growth period marked by significant orthodontic and orthopedic changes [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Early interceptive treatment during this phase is essential for guiding skeletal development and managing arch discrepancies, which usually involve fixed or removable expansion appliances [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Clear aligners, initially developed for adults, have increasingly been adapted for pediatric use because of their aesthetic benefits and clinical effectiveness in mild to moderate malocclusions. Invisalign First\u0026reg; (Align Technology, Santa Clara, CA, USA), introduced in 2018 [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], was specifically developed for mixed dentition, allowing controlled incremental tooth movement with sequential removable aligners tailored to growing jaws and erupting teeth [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Clinical evidence suggests that Invisalign first can effectively address mild arch deficiencies and contribute to dentoalveolar expansion, although treatment outcomes remain dependent on patient compliance [\u003cspan additionalcitationids=\"CR6\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eInvisalign first is indicated during the mixed dentition phase, a period of rapid growth when children often need vitamin and mineral supplements. Pediatric syrups usually contain iron, vitamin C, B-complex vitamins, zinc, colourants, and acidic flavoring agents, many of which have a low pH and chromogenic potential [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Previous studies have shown that such liquid formulations can cause discoloration and changes in the translucency of resin-based restorative materials due to their acidic and staining components [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003cp\u003ePatients are advised to drink only water while wearing aligners; however, they often consume pigmented drinks, which can change the polymer structure and decrease transparency [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Although each aligner is typically worn for a short time (one to two weeks), discoloration can still be clinically significant. Exposure to common beverages such as coffee, tea, red wine, soda, and other acidic drinks can significantly alter the chemical composition of clear aligners, potentially affecting patient motivation [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe evidence suggests that compliance with removable appliances in children may also be inconsistent, particularly regarding recommended daily wear time and adherence to professional instructions [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Some pediatric patients might wear aligners while drinking beverages or taking supplements, which can lead to staining. This discoloration can affect the appearance of the aligners and might make patients less willing to wear them as instructed, possibly impacting the success of the treatment.\u003c/p\u003e \u003cp\u003eAdditionally, although methods such as brushing and commercial aligner-cleaning tablets are advised for maintaining aligners, their effectiveness in removing residues or stains from pediatric medicinal syrups remains uncertain. To the authors\u0026rsquo; knowledge, no prior research has examined how pediatric medicinal syrups affect the optical properties of Invisalign First aligner materials or compared different cleaning methods for eliminating these residues. Therefore, the aims of this in vitro study were i) to evaluate the effects of iron and multivitamin pediatric syrups on the color stability and translucency of Invisalign First aligner material and ii) to assess the cleaning efficacy of different maintenance protocols (toothbrushing, cleaning tablets, and their combined use in removing syrup-induced discoloration and residues from aligners). The null hypotheses tested were as follows: i) exposure to iron and multivitamin syrups would not cause significant changes in the color or translucency of the Invisalign First aligner material; and (ii) there would be no difference among the evaluated cleaning protocols (toothbrushing, cleaning tablets, and the combined use of both methods) in their ability to remove syrup-induced discoloration and residues from the aligners.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cp\u003eAs this was an in vitro study using commercially available materials and no human or animal subjects were involved, ethical approval was not needed.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy design and sample size\u003c/h2\u003e \u003cp\u003eA power analysis was performed for a two-way factorial design via G*Power software (version 3.1.9.7; Heinrich-Heine University, D\u0026uuml;sseldorf, Germany). Assuming a 95% confidence level (α\u0026thinsp;=\u0026thinsp;0.05), 85% statistical power (1\u0026ndash;β\u0026thinsp;=\u0026thinsp;0.85), and an effect size of f\u0026thinsp;=\u0026thinsp;0.25, the minimum required sample size was calculated as 90 samples [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Based on this calculation, eight samples were allocated to each subgroup, resulting in a total of 96 samples across 12 subgroups included in the study.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eSpecimen preparation\u003c/h3\u003e\n\u003cdiv class=\"Heading\"\u003eSpecimen preparation\u003c/div\u003e \u003cp\u003eInvisalign First\u0026reg; (Align Technology, Santa Clara, CA, USA) was fabricated from a mixed‑dentition digital model according to the manufacturer\u0026rsquo;s protocols. Standardization targeted the maxillary central incisor (tooth #11) region. The samples were divided into three main groups, each further subdivided into four subgroups according to the cleaning protocol applied.\u003c/p\u003e \u003cp\u003eThe main groups were defined as follows:\u003c/p\u003e \u003cp\u003eGroup 1: Control group (artificial saliva exposure)\u003c/p\u003e \u003cp\u003eGroup 2: Iron syrup exposure\u003c/p\u003e \u003cp\u003eGroup 3: Multivitamin syrup exposure\u003c/p\u003e \u003cp\u003eEach group was further divided into four subgroups:\u003c/p\u003e \u003cp\u003eSubgroup A: No cleaning protocol was applied\u003c/p\u003e \u003cp\u003eSubgroup B: Toothbrushing only\u003c/p\u003e \u003cp\u003eSubgroup C: Cleaning tablet only\u003c/p\u003e \u003cp\u003eSubgroup D: Combinations of toothbrushing and cleaning tablets\u003c/p\u003e \u003cp\u003eThe detailed distribution and workflow of the experimental groups are presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\n\u003ch3\u003eSolutions and exposure protocol\u003c/h3\u003e\n\u003cp\u003ePreexperiment measurements of color and translucency were conducted as described below. For the iron exposure group, 5 mL of Ferro Sanol B pediatric syrup was used. Each 5 mL dose provides 112.5 mg of iron(II)-glycine sulfate complex, equivalent to 20 mg of Fe\u0026sup2;⁺. It also contains 0.43 mg of riboflavin-5-sodium phosphate, 0.32 mg of vitamin B1 (thiamine hydrochloride), and 0.63 mg of vitamin B6 (pyridoxine hydrochloride). The formulation also includes excipients such as ascorbic acid, refined sugar, glucose monohydrate, sorbitol, sulfuric acid (95\u0026ndash;98%), orange flavor, pear flavor, and deionized water.\u003c/p\u003e \u003cp\u003eIn Group 1, the samples were stored in artificial saliva (sodium chloride (0.4 g/l), potassium chloride (0.4 g/l), calcium chloride\u0026middot;H2O (0.795 g/l), sodium dihydrogen phosphate\u0026middot;H2O (0.69 g/l), sodium sulfur\u0026middot;9H2O (0.005 g/l), and 1000 mL distilled water) for one week [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFor the multivitamin exposure group, Argivit Immun-C syrup was used. The formulation contained deionized water, sorbitol, glycerol, black elderberry extract (250 mg per dose), L-ascorbic acid (vitamin C; 250 mg), zinc gluconate (5 mg), quercetin (50 mg), lactoferrin (25 mg), grape seed extract (5 mg), sodium carboxymethyl cellulose, polysorbate 80, potassium sorbate, xanthan gum, sucralose, sodium selenite (50 \u0026micro;g), and mixed flavoring agents.\u003c/p\u003e \u003cp\u003eIn Groups 2 and 3, each aligner specimen was immersed in 5 mL of undiluted pediatric syrup placed in a test tube. The samples were agitated for 1 min daily, and both the buccal and palatal surfaces were gently agitated via an applicator to ensure contact of the solution with the inner and outer surfaces of the aligner material. This procedure was intended to simulate daily oral exposure of clear aligners to pediatric liquid supplements [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e After immersion, the cleaning protocols were applied according to the subgroup allocation.\u003c/p\u003e\n\u003ch3\u003eCleaning protocols\u003c/h3\u003e\n\u003cp\u003eSubgroup A: Specimens were rinsed with distilled water for 5 seconds.\u003c/p\u003e \u003cp\u003eSubgroup B (Mechanical cleaning): Specimens were cleaned once daily with an electric toothbrush in continuous mode (Oral-B Genius Pro 9000; Braun, Melsungen, Germany). Brushing was performed once daily for 30 seconds using a pea-sized amount of toothpaste (Sensodyne Clinical Repair; Haleon, Weybridge, United Kingdom), and the samples were subsequently rinsed with warm water for 5 seconds, following the manufacturer\u0026rsquo;s aligner cleaning recommendations [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSubgroup C (chemical cleaning): Specimens were immersed in glass water at room temperature to prevent potential deformation of the aligner material. A Corega BioFormula cleaning tablet (Stafford-Miller, Dungarvan, Co. Waterford, Ireland) was dissolved in the water, and each sample was immersed in the solution for 5 minutes daily, followed by rinsing with distilled water for 5 seconds [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSubgroup D (Mechanical\u0026thinsp;+\u0026thinsp;Chemical cleaning): The samples were first cleaned via the toothbrushing protocol described above and then immersed in the cleaning tablet solution, and both methods were applied sequentially.\u003c/p\u003e \u003cp\u003eThe immersion and cleaning procedures were repeated daily for one week, simulating the typical wear period of a single Invisalign First aligner, which is approximately one week before replacement with the next aligner in the treatment sequence. Between immersion periods, the samples were stored in distilled water.\u003c/p\u003e\n\u003ch3\u003eProcedure for measurement of color values\u003c/h3\u003e\n\u003cp\u003eThe color values (L, a, b) of the aligners were measured on a white background (L\u0026thinsp;=\u0026thinsp;96, a\u0026thinsp;=\u0026thinsp;0, b\u0026thinsp;=\u0026thinsp;1) and black background (L\u0026thinsp;=\u0026thinsp;8, a\u0026thinsp;=\u0026thinsp;1, b=-1) (GC3; Danes Picta) via a spectrophotometer (VITA Easyshade V, VITA Zahnfabrik, Bad S\u0026auml;ckingen, Germany). The \u0026ldquo;L\u0026rdquo; parameter represents lightness, the \u0026ldquo;a\u0026rdquo; parameter represents the color coordinates between red (+) and green (-), and the \u0026ldquo;b\u0026rdquo; parameter represents the color coordinates between yellow (+) and blue (-). Measurements were performed under D65 conditions [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Color measurements were performed via a spectrophotometer calibrated according to the manufacturer's instructions. A probe tip with a diameter of 5 mm was placed at the center of each sample. A silicone matrix was prepared to standardize the color measurement area and was used as a template. A circular window with a diameter of 6 mm was created in the silicone matrix via a circular cutter, and the aperture was placed in the middle third of the buccal surface to ensure consistent measurement. Each sample was measured three times, and the average value of these measurements was recorded. Color coordinates (L*, a*, b*) were obtained at two time points: baseline (T0) and after immersion in the solutions (T1).\u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eDetermination of color change values\u003c/h2\u003e \u003cp\u003eThe color change (ΔE00) values were calculated on the basis of white background data. Three measurements were taken for each sample, and their average was used as the representative color value. The color change values were calculated via the CIEDE2000 color difference formula in the T0\u0026ndash;T1 time interval [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]:\u003c/p\u003e \u003cp\u003e\u003cimg src=\"https://myfiles.space/user_files/127393_c7e80a1c9bb65875/127393_custom_files/img1777278815.png\" style=\"width: 607px;\"\u003e\u003c/p\u003e \u003cp\u003ewhere Δ\u003cem\u003eL\u0026rsquo;\u003c/em\u003e, Δ\u003cem\u003eC\u0026rsquo;\u003c/em\u003e, and Δ\u003cem\u003eH\u0026rsquo;\u003c/em\u003e represent the variations in lightness, chroma, and hue between the two samples, respectively. Weighting functions (\u003cem\u003eS\u003c/em\u003eL, \u003cem\u003eS\u003c/em\u003eC, and \u003cem\u003eS\u003c/em\u003eH) are used to modify the total color difference on the basis of the location of the color difference pair within the L, a, and b values. The parametric factors (\u003cem\u003eK\u003c/em\u003eL, \u003cem\u003eK\u003c/em\u003eC, and \u003cem\u003eK\u003c/em\u003eH) function as correction terms for the experimental settings, with values set at 1:1:1 in the current research. The rotation factor (RT) defines the relationship between color and hue variations in the blue spectrum [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Metric discontinuities due to mean hue computation and hue difference computation were considered in the ΔE00 calculation [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. All values of the color differences were clinically interpreted by comparison with their respective 50:50% thresholds for perceptibility (PT00) and acceptability (AT00), which were determined in the literature [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e] and recommended by the Technical Report ISO/TR 28642:2016 [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. In this study, ΔE00 differences were evaluated using thresholds of 50%:50% perceptibility (PT: 0.8 ΔE00) and 50%:50% acceptability (AT: 1.8 ΔE00) [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eDetermination of relative translucency parameter values\u003c/h3\u003e\n\u003cp\u003eColor values were measured on both black and white backgrounds. Relative translucency parameter (RTP) values were recorded at T0 and T1. The formula CIEDE2000 (1:1:1:1) was used to calculate the RTP00 values. The RTP00 of each sample was calculated via the following formula [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]:\u003c/p\u003e \u003cp\u003e\u003cimg src=\"https://myfiles.space/user_files/127393_c7e80a1c9bb65875/127393_custom_files/img1777278967.png\" style=\"width: 465px;\"\u003e\u003c/p\u003e \u003cp\u003e\u0026ldquo;B\u0026rdquo; and \u0026lsquo;W\u0026rsquo; denote the lightness (L\u0026rsquo;), chroma (C\u0026rsquo;), and hue (H') of the samples against black and white backgrounds, respectively. Weighting functions (SL, SC, and SH) are used to modify the total color difference on the basis of the location of the color difference pair within the L, a, and b color space. The parametric factors (KL, KC and KH) serve as correction terms for the experimental settings, and in this investigation, RTP00 (1:1:1) values were used. The rotation factor (RT) defines the relationship between color and hue variations in the blue spectrum [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe translucency value indicates the degree of translucency of the material and ranges from 0\u0026ndash;100; values closer to 0 indicate lower translucency, whereas values closer to 100 indicate higher translucency. In this study, ΔTP00 differences were evaluated using thresholds of 50%:50% perceptibility (TPT: 0.62 ΔTP00) and 50%:50% acceptability (TAT: 2.62 ΔTP00). The ranges for the ΔRTP00 values were determined as T0\u0026ndash;T1. The perceptibility threshold for the relative translucency parameter difference (ΔRTP00) was set at 0.62, whereas the acceptability threshold was set at 2.62 [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e].\u003c/p\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eThe data obtained were analyzed with IBM SPSS V27 (IBM, Armonk, NY, USA). The normality of the data distribution was assessed via the Kolmogorov\u0026ndash;Smirnov test, and the homogeneity of variance was evaluated via Levene\u0026rsquo;s test. As a result, parametric tests were performed for the statistical analysis. The ΔE00 and ΔRTP00 values were evaluated via generalized linear model (GLM; two-way model) analysis (solution, cleaning method, and solution \u0026times; cleaning method). RTP00 values were evaluated via generalized linear model (GLM) three-way analysis (solution, cleaning method, time and interactions). The dependent variables were continuously measured and modeled under a normal distribution. When significant main or interaction effects were detected, pairwise comparisons were performed via Bonferroni correction. The results are presented as the means\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviations. The significance level was set at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eColor change (ΔE00) results\u003c/h2\u003e \u003cp\u003eThe GLM results for ΔE00 are presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The GLM results for color change (ΔE00) revealed that the main effects of the solution and cleaning methods were statistically significant (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The means and standard deviations of the ΔE00 values for all the groups are presented in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. When the solutions were compared, the greatest color change was observed in the iron supplement group (6.48\u0026thinsp;\u0026plusmn;\u0026thinsp;1.87) (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The lowest value was found in the artificial saliva (control) group (3.01\u0026thinsp;\u0026plusmn;\u0026thinsp;1.18). Among the cleaning methods, the noncleaned group presented the greatest color change (5.75\u0026thinsp;\u0026plusmn;\u0026thinsp;2.39) (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The mechanical (4.79\u0026thinsp;\u0026plusmn;\u0026thinsp;2.06) and chemical (4.81\u0026thinsp;\u0026plusmn;\u0026thinsp;2.19) cleaning methods presented similar ΔE00 values. The lowest color change was observed in the combined mechanical\u0026thinsp;+\u0026thinsp;chemical cleaning group (3.80\u0026thinsp;\u0026plusmn;\u0026thinsp;1.69) (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eGLM results for color change and translucency change *Generalized linear models\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eColor change\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eWald Chi-Square\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003edf\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003ep*\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntercept\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1036.392\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSolution\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e90.864\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMethod\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21.525\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSolution * Method\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.632\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.592\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTranslucency change\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eWald Chi-Square\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003edf\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003ep*\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntercept\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e167.193\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSolution\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e68.111\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMethod\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.207\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.240\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSolution * Method\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5.711\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.456\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDifferences of color change values between the groups\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cb\u003eMaterials\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003eSolutions\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eArtificial saliva\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eIron supplement\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMultivitamin\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eTotal mean\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNoncleaned\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.39\u0026thinsp;\u0026plusmn;\u0026thinsp;1.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.07\u0026thinsp;\u0026plusmn;\u0026thinsp;1.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.80\u0026thinsp;\u0026plusmn;\u0026thinsp;1.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.75\u0026thinsp;\u0026plusmn;\u0026thinsp;2.39a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMechanical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.11\u0026thinsp;\u0026plusmn;\u0026thinsp;1.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.26\u0026thinsp;\u0026plusmn;\u0026thinsp;1.96\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.99\u0026thinsp;\u0026plusmn;\u0026thinsp;1.59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.79\u0026thinsp;\u0026plusmn;\u0026thinsp;2.06b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChemical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.03\u0026thinsp;\u0026plusmn;\u0026thinsp;1.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.53\u0026thinsp;\u0026plusmn;\u0026thinsp;1.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.87\u0026thinsp;\u0026plusmn;\u0026thinsp;2.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.81\u0026thinsp;\u0026plusmn;\u0026thinsp;2.19b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMechanical\u0026thinsp;+\u0026thinsp;Chemical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.51\u0026thinsp;\u0026plusmn;\u0026thinsp;0.61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5.08\u0026thinsp;\u0026plusmn;\u0026thinsp;1.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.80\u0026thinsp;\u0026plusmn;\u0026thinsp;2.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.80\u0026thinsp;\u0026plusmn;\u0026thinsp;1.69c\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal mean\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.01\u0026thinsp;\u0026plusmn;\u0026thinsp;1.18A\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.48\u0026thinsp;\u0026plusmn;\u0026thinsp;1.87B\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.86\u0026thinsp;\u0026plusmn;\u0026thinsp;1.86C\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.79\u0026thinsp;\u0026plusmn;\u0026thinsp;2.18\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003emean\u0026plusmn;standard deviation a-c There is no difference between methods with the same letter in the same column. A-C There is no difference between solutions with the same letter in the row.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eTranslucency change (ΔRTP00) results\u003c/h2\u003e \u003cp\u003eFor the RTP change (ΔRTP), GLM analysis demonstrated that the main effect of solution was statistically significant (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The greatest decrease in RTP00 was observed in the iron supplement group (-5.89\u0026thinsp;\u0026plusmn;\u0026thinsp;2.31) (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The lowest decrease in RTP00 was observed in the artificial saliva group (-0.44\u0026thinsp;\u0026plusmn;\u0026thinsp;3.97) (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDifferences of translucency change values between the groups\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cb\u003eMaterials\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003eSolutions\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eArtificial saliva\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eIron supplement\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMultivitamin\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eTotal mean\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNoncleaned\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.03\u0026thinsp;\u0026plusmn;\u0026thinsp;3.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-7.92\u0026thinsp;\u0026plusmn;\u0026thinsp;1.81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-5.67\u0026thinsp;\u0026plusmn;\u0026thinsp;1.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e-4.54\u0026thinsp;\u0026plusmn;\u0026thinsp;4.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMechanical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.62\u0026thinsp;\u0026plusmn;\u0026thinsp;4.76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-6.05\u0026thinsp;\u0026plusmn;\u0026thinsp;2.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-3.77\u0026thinsp;\u0026plusmn;\u0026thinsp;2.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e-3.48\u0026thinsp;\u0026plusmn;\u0026thinsp;3.92\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChemical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.61\u0026thinsp;\u0026plusmn;\u0026thinsp;3.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-5.15\u0026thinsp;\u0026plusmn;\u0026thinsp;1.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-4.73\u0026thinsp;\u0026plusmn;\u0026thinsp;2.61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e-3.50\u0026thinsp;\u0026plusmn;\u0026thinsp;3.30\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMechanical\u0026thinsp;+\u0026thinsp;Chemical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.50\u0026thinsp;\u0026plusmn;\u0026thinsp;5.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-4.41\u0026thinsp;\u0026plusmn;\u0026thinsp;1.84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-3.96\u0026thinsp;\u0026plusmn;\u0026thinsp;2.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e-2.96\u0026thinsp;\u0026plusmn;\u0026thinsp;3.64\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal mean\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.44\u0026thinsp;\u0026plusmn;\u0026thinsp;3.97A\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-5.89\u0026thinsp;\u0026plusmn;\u0026thinsp;2.31B\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-4.53\u0026thinsp;\u0026plusmn;\u0026thinsp;2.15C\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e-3.62\u0026thinsp;\u0026plusmn;\u0026thinsp;3.71\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003emeans\u0026plusmn;standard deviations. A-B There is no difference between solutions with the same letter in the row.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eFor the time-dependent RTP values, the main effects of solution (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), method (p\u0026thinsp;=\u0026thinsp;0.033), and time (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) were statistically significant. Additionally, the solution \u0026times; time interaction was significant (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). The lowest RTP values were observed in the iron supplement \u0026times; baseline (t0) interaction (32.78\u0026thinsp;\u0026plusmn;\u0026thinsp;1.98) (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eGLM results for RTP values before and after immersion in solutions\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSource\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eWald Chi-Square\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003edf\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003ep*\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntercept\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e44484.518\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSolution\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e14.295\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMethod\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e8.731\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e0.033\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTime\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e159.448\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSolution * Method\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5.721\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.455\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSolution * Time\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e64.956\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMethod * Time\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4.013\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.260\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSolution * Method * Time\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5.446\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.488\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e*Generalized linear models\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDescriptive statistics for RTP values before (T0) and after immersion (T1)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003eTime\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSolution\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMethods\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eBaseline (t0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAfter immersed (t1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"4\" rowspan=\"5\"\u003e \u003cp\u003e\u003cb\u003eArtificial saliva\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNoncleaned\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31.03\u0026thinsp;\u0026plusmn;\u0026thinsp;2.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e30.99\u0026thinsp;\u0026plusmn;\u0026thinsp;2.68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e31.01\u0026thinsp;\u0026plusmn;\u0026thinsp;2.57\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMechanical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31.84\u0026thinsp;\u0026plusmn;\u0026thinsp;2.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e31.21\u0026thinsp;\u0026plusmn;\u0026thinsp;3.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e31.53\u0026thinsp;\u0026plusmn;\u0026thinsp;2.69\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eChemical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31.02\u0026thinsp;\u0026plusmn;\u0026thinsp;2.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e30.40\u0026thinsp;\u0026plusmn;\u0026thinsp;2.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e30.71\u0026thinsp;\u0026plusmn;\u0026thinsp;2.29\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMechanical\u0026thinsp;+\u0026thinsp;Chemical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31.15\u0026thinsp;\u0026plusmn;\u0026thinsp;1.96\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e30.65\u0026thinsp;\u0026plusmn;\u0026thinsp;4.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e30.90\u0026thinsp;\u0026plusmn;\u0026thinsp;3.05\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31.26\u0026thinsp;\u0026plusmn;\u0026thinsp;2.20ef\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e30.81\u0026thinsp;\u0026plusmn;\u0026thinsp;3.00f\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e31.04\u0026thinsp;\u0026plusmn;\u0026thinsp;2.62X\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"4\" rowspan=\"5\"\u003e \u003cp\u003e\u003cb\u003eIron supplement\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNoncleaned\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e33.22\u0026thinsp;\u0026plusmn;\u0026thinsp;2.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e25.29\u0026thinsp;\u0026plusmn;\u0026thinsp;1.49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e29.25\u0026thinsp;\u0026plusmn;\u0026thinsp;4.48\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMechanical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e33.80\u0026thinsp;\u0026plusmn;\u0026thinsp;2.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e27.74\u0026thinsp;\u0026plusmn;\u0026thinsp;2.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e30.77\u0026thinsp;\u0026plusmn;\u0026thinsp;3.75\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eChemical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31.37\u0026thinsp;\u0026plusmn;\u0026thinsp;1.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e26.21\u0026thinsp;\u0026plusmn;\u0026thinsp;1.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e28.79\u0026thinsp;\u0026plusmn;\u0026thinsp;2.91\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMechanical\u0026thinsp;+\u0026thinsp;Chemical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32.74\u0026thinsp;\u0026plusmn;\u0026thinsp;1.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e28.32\u0026thinsp;\u0026plusmn;\u0026thinsp;1.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e30.53\u0026thinsp;\u0026plusmn;\u0026thinsp;2.70\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32.78\u0026thinsp;\u0026plusmn;\u0026thinsp;1.98c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e26.89\u0026thinsp;\u0026plusmn;\u0026thinsp;1.94bd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e29.84\u0026thinsp;\u0026plusmn;\u0026thinsp;3.55Y\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"4\" rowspan=\"5\"\u003e \u003cp\u003e\u003cb\u003eMultivitamin\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNoncleaned\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32.40\u0026thinsp;\u0026plusmn;\u0026thinsp;0.90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e26.73\u0026thinsp;\u0026plusmn;\u0026thinsp;1.57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e29.57\u0026thinsp;\u0026plusmn;\u0026thinsp;3.18\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMechanical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31.85\u0026thinsp;\u0026plusmn;\u0026thinsp;2.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e28.07\u0026thinsp;\u0026plusmn;\u0026thinsp;1.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e29.96\u0026thinsp;\u0026plusmn;\u0026thinsp;2.60\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eChemical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32.16\u0026thinsp;\u0026plusmn;\u0026thinsp;1.99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e27.43\u0026thinsp;\u0026plusmn;\u0026thinsp;2.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e29.80\u0026thinsp;\u0026plusmn;\u0026thinsp;3.17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMechanical\u0026thinsp;+\u0026thinsp;Chemical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32.44\u0026thinsp;\u0026plusmn;\u0026thinsp;1.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e28.47\u0026thinsp;\u0026plusmn;\u0026thinsp;1.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e30.45\u0026thinsp;\u0026plusmn;\u0026thinsp;2.60\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32.21\u0026thinsp;\u0026plusmn;\u0026thinsp;1.64ace\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e27.68\u0026thinsp;\u0026plusmn;\u0026thinsp;1.80b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e29.94\u0026thinsp;\u0026plusmn;\u0026thinsp;2.85Y\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"4\" rowspan=\"5\"\u003e \u003cp\u003e\u003cb\u003eTotal\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNoncleaned\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32.22\u0026thinsp;\u0026plusmn;\u0026thinsp;2.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e27.67\u0026thinsp;\u0026plusmn;\u0026thinsp;3.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e29.94\u0026thinsp;\u0026plusmn;\u0026thinsp;3.51ADC\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMechanical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32.49\u0026thinsp;\u0026plusmn;\u0026thinsp;2.36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e29.01\u0026thinsp;\u0026plusmn;\u0026thinsp;2.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e30.75\u0026thinsp;\u0026plusmn;\u0026thinsp;3.06BE\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eChemical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31.52\u0026thinsp;\u0026plusmn;\u0026thinsp;1.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e28.01\u0026thinsp;\u0026plusmn;\u0026thinsp;2.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e29.77\u0026thinsp;\u0026plusmn;\u0026thinsp;2.87C\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMechanical\u0026thinsp;+\u0026thinsp;Chemical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32.11\u0026thinsp;\u0026plusmn;\u0026thinsp;1.76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e29.15\u0026thinsp;\u0026plusmn;\u0026thinsp;2.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e30.63\u0026thinsp;\u0026plusmn;\u0026thinsp;2.74DE\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32.09\u0026thinsp;\u0026plusmn;\u0026thinsp;2.03x\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e28.46\u0026thinsp;\u0026plusmn;\u0026thinsp;2.85y\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e30.27\u0026thinsp;\u0026plusmn;\u0026thinsp;3.08\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003emean\u0026plusmn;standard deviation; A-E There is no difference between methods with the same letter in the same column. X-Y There is no difference between solutions with the same letter in the column. x-y There is no difference between times with the same letter in the row. a-f There is no difference between interactions (solution \u0026times; time) with the same letter. The total values represent the means obtained from GLM analyses and are provided to show the data for the main effects and interaction values; the inferential results are based on GLM tests.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn this study, the effects of pediatric iron and multivitamin syrups on the optical properties of Invisalign First orthodontic aligners were evaluated, and the effectiveness of different cleaning protocols in reducing syrup-induced discoloration was examined. The findings showed that exposure to pediatric medicinal syrups significantly affected both the color stability and translucency of the aligner material. Among the tested solutions, the iron-containing syrup produced the greatest color change and the most pronounced reduction in translucency, whereas the combined mechanical and chemical cleaning protocol yielded the lowest color change values. Accordingly, both null hypotheses were rejected.\u003c/p\u003e \u003cp\u003eThe discoloration observed in the iron syrup group can be explained by both chemical and material-related mechanisms. Iron-containing formulations may promote the formation of dark complexes and enhance pigment deposition on material surfaces. In addition, pediatric syrups often contain chromogenic agents, acidic components, and viscous excipients that prolong the contact time and facilitate stain adsorption [\u003cspan additionalcitationids=\"CR9\" citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. From a materials perspective, Invisalign First aligners are fabricated from 0.75 mm-thick thermoplastic polyurethane with a heterogeneous polymer network that may allow diffusion of staining molecules into the matrix [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. Exposure to low-pH solutions may further induce surface softening, increasing susceptibility to pigment penetration and retention [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. The lower color change observed in the multivitamin syrup group than in the iron syrup group can be explained by differences in chromogenic composition and metal ion content. Iron-containing formulations can undergo oxidation reactions and form dark-colored metal complexes that increase pigment accumulation and staining on polymer surfaces [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. In contrast, multivitamin syrups primarily contain organic pigments and vitamins with lower chromogenic potential, which leads to a reduced color change. The staining and oxidation processes caused by metal ions increase color changes in dental materials by promoting pigment adsorption and chemical interactions with the polymer matrix. Furthermore, previous studies on transparent dental restoratives have shown that the staining intensity depends on the chemical composition and chromogenic potential of the immersion solution, which supports the current findings [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThese findings are consistent with previous studies demonstrating that pediatric liquid medications can adversely affect the color stability of dental materials. T\u0026uuml;z\u0026uuml;ner et al. reported that iron-containing pediatric drugs caused the greatest discoloration among the tested formulations, whereas other studies have shown that multivitamin syrups and similar liquid supplements can also induce clinically perceptible color changes due to their chromogenic and acidic composition [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. In addition, studies on clear aligners have demonstrated that thermoplastic orthodontic materials are susceptible to staining when exposed to pigmented beverages such as coffee and tea, supporting the present results [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn addition to color changes, a significant reduction in translucency was observed, particularly in the iron syrup group. The optical properties of materials are closely related to light transmission, absorption, and scattering. Materials with higher light transmittance appear more transparent, whereas increased absorption and pigment penetration may reduce transparency [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Our results may be explained by the adsorption of pigments onto the polymer surface or by microstructural alterations occurring within the material. Furthermore, the observed decrease in RTP00 values after one week of exposure suggests that contact with artificial saliva and minor surface changes over time may also influence translucency [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. However, the magnitude of the observed translucency changes remained below clinically acceptable thresholds. Since one of the main advantages of clear orthodontic appliances is their aesthetic invisibility, maintaining translucency is an important factor for patient satisfaction [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. The findings of the present study indicate that appropriate cleaning protocols may contribute to preserving the aesthetic properties of clear aligners. In the clinic, orthodontists should consider the potential staining effects of liquid medications used in pediatric patients and provide guidance on appropriate cleaning protocols.\u003c/p\u003e \u003cp\u003eIn this study, combining mechanical and chemical cleaning methods resulted in the least color change, which aligns with existing research that suggests that such combined approaches are more effective for cleaning orthodontic appliances. The superior performance of the combined protocol may be explained by its dual mechanism of action: mechanical brushing disrupts and removes loosely bound surface deposits, whereas chemical cleaning products, such as effervescent tablets, facilitate the dissolution of organic residues and promote the breakdown of pigment complexes adhering to the material surface. This complementary effect enhances cleaning efficacy by removing both superficial and strongly attached stains. Chang et al. reported that this combination effectively reduces staining and maintains the translucency of Essix retainers [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. Similarly, Wible et al. reported that long-term cleaning can significantly impact the color and surface quality of copolyester retainers [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. Several other studies [\u003cspan additionalcitationids=\"CR32 CR33\" citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e] support the effectiveness of denture-cleaning tablets and specialized solutions in minimizing staining, although some agents may negatively affect material properties after extended use [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]. Consequently, consistent and thorough cleaning is crucial to prevent biofilm buildup and pigment deposits during prolonged aligner wear [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eClear aligners are increasingly preferred in orthodontic treatment because of their aesthetic advantages and patient comfort. Therefore, maintaining the transparency and color stability of the material throughout treatment is of clinical importance. Color changes may negatively affect the aesthetic appearance of the appliance, particularly in the anterior region, where visibility is highest, potentially reducing patient satisfaction and treatment compliance [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. In the present study, all color measurements were performed on the buccal surfaces of the maxillary anterior teeth, as this region is the most clinically visible region during speech and smiling, thereby providing a more relevant and sensitive assessment of optical changes under real-life conditions [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThis study has several key strengths. One of the few studies that have explored how pediatric medicinal syrups affect the optical properties of Invisalign First aligner materials is the addition of new data to the field. Additionally, assessing both color stability and translucency at the same time provides a more complete picture of aesthetic changes. Notably, this study introduces a clinically relevant and less explored method by focusing on staining agents routinely prescribed to pediatric patients instead of more optional consumables such as coffee or tea. This approach offers a more realistic clinical context and broadens the understanding of staining in clear aligners. Moreover, comparing different cleaning protocols provides useful insights into effective ways to maintain the aesthetic quality of aligners in everyday use.\u003c/p\u003e \u003cp\u003eThe 1-minute daily immersion protocol used in this study simulates the short but repeated exposure of clear aligners to pediatric syrups under clinical conditions. In routine practice, pediatric syrups are typically consumed quickly and do not remain in the mouth for long, whereas aligners are worn continuously for approximately 1\u0026ndash;2 weeks. This causes repeated exposure to staining agents, and even brief contact with chromogenic solutions can accumulate over time, leading to noticeable optical changes. Similar to this study, previous in vitro research on aligner staining used time-controlled immersion protocols to mimic real-life exposure to beverages and solutions during aligner wear, supporting the clinical importance of these models [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e, \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSeveral limitations of this study should be acknowledged. First, the experimental conditions were conducted in vitro and may not fully reflect the complex oral environment, where factors such as saliva, temperature changes, and mechanical wear can influence material behavior. Second, the immersion protocol simulated short-term daily exposure rather than continuous intraoral conditions. Third, only two types of pediatric medicinal syrups have been evaluated, and different formulations may have varying effects on aligner materials. Future studies should include a wider range of pediatric medications, longer exposure periods, and additional factors, such as salivary components, to better simulate clinical conditions.\u003c/p\u003e \u003cp\u003eDespite these limitations, this study provides clinically relevant information on the effects of pediatric medicinal syrups on clear aligners and highlights the importance of appropriate cleaning strategies in daily practice. Understanding these interactions is important for improving patient education and aligner maintenance strategies. Clinicians should inform patients and caregivers about the potential staining effects of pediatric syrups and emphasize the importance of removing aligners before intake and following appropriate cleaning procedures.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eWithin the limitations of this in vitro study, the following conclusions can be drawn:\u003c/p\u003e \u003cp\u003e \u003col\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003ePediatric iron and multivitamin syrups cause significant optical changes in Invisalign First aligners, with iron formulations producing the greatest discoloration and translucency loss.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eCombined mechanical\u0026ndash;chemical cleaning (toothbrushing plus cleaning tablets) reduces syrup‑induced discoloration more effectively than single‑method protocols do but cannot fully restore the original optical properties.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eClinicians should advise families to remove aligners before syrup intake and to adopt combined daily cleaning routines to preserve aesthetics and support treatment compliance.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003c/ol\u003e \u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eConflicts of interest:\u003c/h2\u003e \u003cp\u003eThe authors declare that they have no conflicts of interest related to this work.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding:\u003c/h2\u003e \u003cp\u003eThis research received no external funding and was conducted without any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eE.K.: Conceptualisation, methodology, investigation, data acquisition, and writing\u0026mdash;original draft. M.F.: Methodology, data collection, formal analysis, and writing\u0026mdash;original draft. I.E.G.: Conceptualisation, methodology, writing\u0026mdash;original draft, review and editing, and supervision.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eMartins, M., Costa, C., Abr\u0026atilde;o, J. \u0026amp; Borri, M. Expans\u0026atilde;o r\u0026aacute;pida da maxila: an\u0026aacute;lise da densidade radiogr\u0026aacute;fica da sutura palatina mediana e sua correla\u0026ccedil;\u0026atilde;o nos est\u0026aacute;gios de neoforma\u0026ccedil;\u0026atilde;o \u0026oacute;ssea, por meio de imagem digitalizada. \u003cem\u003eRev Dent. Press. Ortod E Ortop. 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L. et al. Colour stabilities of three types of orthodontic clear aligners exposed to staining agents. \u003cem\u003eInt. J. Oral Sci.\u003c/em\u003e \u003cb\u003e8\u003c/b\u003e, 246\u0026ndash;253 (2016).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFidan, M. \u0026amp; Gelgor, I. E. Effect of aging and mechanical brushing on color stability and translucency of three-dimensionally printed and thermoformed aligners of different thicknesses. \u003cem\u003eAngle Orthod.\u003c/em\u003e \u003cb\u003e96\u003c/b\u003e, 83\u0026ndash;92 (2025).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKobkiatkawin, C., Panyayong, W., Suphangul, S. \u0026amp; Thiradilok, S. Color stability of clear aligners exposed to various beverages: an in vitro study. \u003cem\u003eBMC Oral Health\u003c/em\u003e. \u003cb\u003e25\u003c/b\u003e, 971 (2025).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Cleaning protocols, Clear aligners, Color stability, Pediatric patient, Translucency","lastPublishedDoi":"10.21203/rs.3.rs-9226773/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9226773/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study evaluated the effects of pediatric iron- and multivitamin-containing syrups on the color stability and translucency of Invisalign First aligners and assessed the effectiveness of different cleaning protocols in reducing discoloration. Ninety-six specimens were divided into three solution groups (artificial saliva, iron syrup, and multivitamin syrup) and four cleaning subgroups (no cleaning, toothbrushing, cleaning tablets, and combined cleaning). The samples were immersed in the test solutions for 1 minute daily, followed by the assigned cleaning protocols, for one week. Color coordinates (L*, a*, b*) were measured using a spectrophotometer at baseline and after immersion, and color (ΔE00) and translucency (ΔRTP00) changes were calculated. Data were analyzed using generalized linear models (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Both solution type and cleaning protocol significantly affected color (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), with iron syrup causing the greatest discoloration (ΔE00: 6.48\u0026thinsp;\u0026plusmn;\u0026thinsp;1.87). Combined cleaning resulted in the lowest color change values. Translucency was also significantly reduced (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), particularly in the iron syrup group (ΔRTP00: \u0026minus;5.89\u0026thinsp;\u0026plusmn;\u0026thinsp;2.31). Pediatric syrups, especially iron-containing formulations, caused clinically perceptible discoloration and reduced translucency in clear aligners. Combined cleaning reduced discoloration, but measurable changes remained. Clinicians should advise removing aligners during syrup intake and maintaining appropriate cleaning routines to preserve aesthetics.\u003c/p\u003e","manuscriptTitle":"Effects of Pediatric Iron and Multivitamin Syrups on Invisalign First Aligners and the Efficacy of Cleaning Methods","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-27 10:52:51","doi":"10.21203/rs.3.rs-9226773/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2026-04-26T09:44:41+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"228155956117840612646194754668530688250","date":"2026-04-26T07:23:10+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-23T17:06:35+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"61703213148784215384826979686259729224","date":"2026-04-19T18:19:12+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"309482014990350579209450248464019749180","date":"2026-04-19T16:42:04+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-19T16:39:58+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-04-16T16:35:29+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-03-31T05:46:31+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-29T08:28:55+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2026-03-29T08:23:56+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"36812012-5342-4ba7-9af1-4f6ce28c73d2","owner":[],"postedDate":"April 27th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"in-revision","subjectAreas":[{"id":67026628,"name":"Health sciences/Diseases"},{"id":67026629,"name":"Health sciences/Health care"},{"id":67026630,"name":"Health sciences/Medical research"}],"tags":[],"updatedAt":"2026-05-11T07:59:03+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-27 10:52:51","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9226773","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9226773","identity":"rs-9226773","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}