Evidence map›Paper›PMID 42642289›Full record

ArticleDental materials : official publication of the Academy of Dental Materials2026

Comparative evaluation of physicochemical, mechanical, and biological properties of biodegradable poly(lactic acid) (PLA) and commercial aligner materials.

Mayuri Parappullil Vellayappan, Sean Johnson, Taylor Stewart, Kristina Astleford-Hopper, Amy Tasca, Jae Sung Lee

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Dental materials : official publication of the Academy of Dental Materials, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
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0citing papers in PubMed
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1 · What the graph read from it

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.

2 · The registry

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.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Mayuri Parappullil VellayappanDivision of Biomaterials, Department of Restorative Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, USA; Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, MN, USA; Department of Materials Engineering, Indian Institute of Science, Bengaluru, Karnataka, India.
Sean JohnsonDivision of Biomaterials, Department of Restorative Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, USA; Cox School of Business, Southern Methodist University, Dallas, TX, USA.
Taylor StewartDivision of Orthodontics, Department of Developmental and Surgical Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, USA.
Kristina Astleford-HopperDivision of Orthodontics, Department of Developmental and Surgical Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, USA.
Amy TascaDivision of Orthodontics, Department of Developmental and Surgical Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, USA.
Jae Sung LeeDivision of Biomaterials, Department of Restorative Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, USA; Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, MN, USA. Electronic address: andjslee@umn.edu.

Funding

Minnesota Craniofacial and Oral Health Research ExperienceR25DE032529 · NIDCR · UNIVERSITY OF MINNESOTA · PI Kim Carpenter Mansky · 2023 to 2026
$521k
NIDCR NIH HHS R25 DE032529
6 · The paper itself

Abstract

objectivesThis study aimed to evaluate bio-based, biodegradable polylactic acid (PLA) as a sustainable material for clear aligners by comparing its physicochemical, mechanical, and biological properties with commercial aligner materials (Essix Ace, Essix C+, Zendura FLX, and Zendura).

methodsPLA and commercial materials, both neat and aged in artificial saliva for up to 14 days, were examined as sheets. Thermal properties were measured using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Mechanical and optical properties were evaluated using a universal testing machine (UTM) and UV-visible spectrophotometry. Degradation behavior was assessed via weight and average molar mass changes, and surface morphology via scanning electron microscopy (SEM). Cytotoxicity was tested using human gingival fibroblasts with an MTT assay.

resultsPLA showed a glass transition temperature of 55.4 °C, melting temperature of 152.1°C, and degradation onset temperature of 362.9 °C, comparable to commercial aligner materials. Its tensile strength and yield stress were similar to those of commercial materials, indicating adequate strength. However, PLA exhibited lower elongation at break and higher Young's modulus, reflecting higher brittleness and stiffness. Aging caused negligible water absorption, minimal weight loss, and minor thermal property change. Mechanical properties remained stable upon aging. Aged PLA was transparent when wet but became hazy when dry, which occurs reversibly. Extracts from PLA were non-cytotoxic, maintaining 90% cell viability in average. SIGNIFICANCE: PLA demonstrated properties comparable to commercial aligner materials, with the exception of increased stiffness and brittleness. Its stability during aging and favorable biocompatibility supports its potential as a sustainable alternative for clear aligner applications.

Indexed as

Artificial salivaBiocompatibilityBiodegradableClear alignersMechanical propertyPLAPolyethylene terephthalate glycolPolylactic acidThermal propertyThermoplastic polyurethane

Identifiers

PMID42642289
PMCPMC13560050

What OpenQuestion holds

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Registered trials

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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.