ArticleBMC oral health2026
Hygroscopic behaviour and colour stability of 3D-printed and thermoformed aligner materials: an in vitro study.
Article in BMC oral health, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundDirectly 3D-printed aligner materials have recently emerged as an alternative to established thermoformed clear aligners. The aim of this in vitro study was to investigate the colour stability, water sorption, and water solubility of directly 3D-printed aligner materials in comparison with an established thermoformed reference, as these properties are essential for clinical performance but currently insufficiently investigated for directly 3D-printed aligners.
methodsTera Harz TC-85DAC, Freeprint Aligner, Freeprint Aligner with digital polishing, Dental LT Clear V2 and one thermoformed polyethylene terephthalate glycol material (Biolon) were examined. Water sorption and solubility were determined after seven days in distilled water at 37 °C. Colour stability was assessed after 12 h of immersion at 37 °C in turmeric, coffee, black tea, orange juice and distilled water. Total colour differences (ΔE*) were calculated spectrophotometrically using the Commission Internationale de l'Éclairage L*a*b* system and converted into National Bureau of Standards units. Data were analysed by one-way ANOVA with Games-Howell post hoc test and by Kruskal-Wallis test with Dunn's test and Bonferroni correction (p < 0.05).
resultsBiolon exhibited the lowest water sorption (mean 10.70 µg/mm³) and negligible solubility (median 0.00 µg/mm³). Among the printed resins, Tera Harz TC-85DAC showed the lowest water sorption (mean 17.28 µg/mm³) and solubility (median 2.50 µg/mm³), whereas Dental LT Clear V2 displayed the highest sorption (mean 29.53 µg/mm³) and Freeprint Aligner with digital polishing the highest solubility (median 17.38 µg/mm³). Turmeric caused the most pronounced discolouration, followed by coffee and black tea, while orange juice and water produced minimal changes. The thermoformed material remained most colour-stable (mean of the median ΔE* values across all immersion media = 4.21), whereas Dental LT Clear V2 showed the greatest discolouration (mean of the median ΔE* values = 27.35). Among the printed resins, Tera Harz TC-85DAC displayed the lowest staining susceptibility.
conclusionsThe tested aligner materials differed markedly in water sorption, solubility, and colour stability. The thermoformed polyethylene terephthalate glycol material consistently showed the most favourable profile. Among the printed resins, Tera Harz TC-85DAC exhibited the most favourable combination of the investigated properties, supporting its potential for clinical application.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.