Evidence map›Paper›PMID 40624404›Full record

ArticleClinical oral investigations2025

Time-dependent microbiome dynamics in orthodontic thermoplastic materials: comparing PETG and TPU.

Tianyi Gao, Jieyu Yun, Yage Zheng, Chuangchuang Mu, Bingjiao Zhao

Abstract readComparative Study
In one paragraph

Article in Clinical oral investigations, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed, 1 pooled it
–field-weighted citation impact
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

3 citing papers in PubMed, 1 synthesis or guideline pooled it.

  1. Pooled it
  2. Review
  3. Article
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

5 authors.

Tianyi GaoDepartment of Orthodontics, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, China.
Jieyu YunDepartment of Orthodontics, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, China.
Yage ZhengDepartment of Orthodontics, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, China.
Chuangchuang MuShanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Fudan University, Shanghai, China. muchuangchuang@fudan.edu.cn.
Bingjiao ZhaoShanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Fudan University, Shanghai, China. joyce_zhao_ortho@fudan.edu.cn.ORCID http://orcid.org/0000-0001-5385-7452

Funding

Shanghai Municipal Health Commission 202240182Shanghai Stomatological Hospital SHH-2022-YJ-A01
6 · The paper itself

Abstract

objectivesThis study compares the effects of thermoplastic polyurethane (TPU) and polyethylene terephthalate glycol (PETG) aligners on the oral microbiome and salivary pH during orthodontic treatment. MATERIALS AND

methodsTen participants wore TPU and PETG aligners for 24 h. At five time points (1 min, 4, 8, 12, and 24 h), saliva was collected for pH analysis, and microbial samples were taken from both aligner and supragingival plaque surfaces for 16S rRNA sequencing. Statistical analyses included repeated Measures ANOVA for pH, Kruskal-Wallis test for alpha diversity, PERMANOVA for beta diversity, and two-way ANOVA for microbial composition.

resultsIn Group PETG, salivary pH significantly decreased from T0 to T4 (p < 0.05). No significant changes in alpha or beta microbiota diversity were observed in either group. Microbial shifts in supragingival plaque microbiomes were detected at T8 in Group PETG, while in Group TPU, these changes became evident between T12 and T24. In aligner microbiomes, Group TPU showed significant reductions in Veillonella, Actinomyces, and Fusobacterium at T24 (p < 0.05). In contrast, Group PETG exhibited significant increases in Streptococcus from T4 to T24 (p < 0.05) and Fusobacterium from T0 to T4 (p < 0.05), followed by a decline from T4 to T24 (p < 0.01).

conclusionsPETG aligners caused significant reductions in salivary pH at T4 and triggered pronounced fluctuations at T8 in supragingival plaque microbiomes. TPU aligners caused a delayed decline in salivary pH between T8 and T12 and drove distinct structural shifts during prolonged wear from T12 to T24. CLINICAL RELEVANCE: Material choice based on microbial impact highlights the need for personalized aligner materials and cleaning cycles.

Indexed as

MicrobiotaOrthodontic AppliancesPolyethylene GlycolsPolyethylene TerephthalatesPolyurethanesSalivaAdolescentAdultFemaleHumansHydrogen-Ion ConcentrationMaleRNA, Ribosomal, 16STime FactorsYoung AdultPolyethylene GlycolsPolyethylene TerephthalatesPolyurethanesRNA, Ribosomal, 16S16S RrnaClear alignersDentistryOral microbiomeOrthodonticsThermoplastic materials

Identifiers

PMID40624404
PMCPMC12234582

What Socratic holds

Textmetadata
LicenceCC BY-NC-ND
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Registered trials

None linked

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 Socratic graph.