87 - Effects of aging on the mechanical properties of GraphyⓇ orthodontic aligners: An in vitro study

IF 3.5 Q1 DENTISTRY, ORAL SURGERY & MEDICINE

Journal of the World Federation of Orthodontists Pub Date : 2025-12-01 Epub Date: 2025-12-09 DOI:10.1016/j.ejwf.2025.07.091

Vande Vannet Bart , Ursat Pauline , Ursat Eric , Hocquel Thibaut , Canceill Thibault

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引用次数: 0

Abstract

Background: Direct 3D printing of aligners using Tera Harz TC-85 material (Graphy^Ⓡ, Seoul, Republic of Korea) eliminates the need for printed dental models, offering a potentially more precise, efficient, and cost-effective alternative. Current guidelines recommend wearing aligners for 22 hours daily and replacing them every 15 days.

Objectives: This in vitro study evaluates the mechanical properties of Tera Harz TC-85 aligners at different time intervals (D0, D7, D14) in artificial saliva to assess force delivery and deformation over time.

Methods: Eighteen identical Class I aligners (GRAPHY^Ⓡ, Forestadent Bernhard Foerster GmbH^Ⓡ, Pforzheim, Germany) were divided into three groups (D0, D7, D14) and subjected to continuous aging in Fusayama-Mayer artificial saliva (Serlabo Technologies, Vedene, France) at 37°C. Following aging, aligners underwent traction testing using a Universal Testing Machine (LRX Plus Dynamometer Lloyd Instruments) to measure maximum tensile and yield strength.

Results: The average rupture force was 169.98 N (SD 32.32, CV 19.02%) at the molars and 222.67 N (SD 35.56, CV 15.97%) at the incisors. Deformation at D0 was significantly different from D7 and D14 in both incisors and molars (p < 0.001).

Conclusions: The mechanical stability of Tera Harz TC-85 suggests that aligners should be replaced weekly rather than every 15 days. Direct 3D printing does not reduce the total number of aligners needed, as shape memory becomes unstable over time.

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老化对GraphyⓇ正畸矫正器力学性能的影响：一项体外研究

背景：使用Tera Harz TC-85材料直接3D打印牙齿矫正器（GraphyⓇ，Seoul, Republic of Korea）消除了对打印牙齿模型的需求，提供了一种潜在的更精确、更高效、更经济的替代方案。目前的指南建议每天佩戴牙齿矫正器22小时，每15天更换一次。目的：本体外研究评估Tera Harz TC-85对准器在人工唾液中不同时间间隔（D0, D7, D14）的力学性能，以评估力传递和变形随时间的变化。方法：18个相同的I类对准器（GRAPHYⓇ，Forestadent Bernhard Foerster GmbHⓇ，Pforzheim, Germany）分为3组（D0, D7, D14），在37°C的Fusayama-Mayer人工唾液（Serlabo Technologies, Vedene, France）中持续老化。老化后，矫直器使用通用试验机（LRX Plus Dynamometer Lloyd Instruments）进行牵引测试，以测量最大拉伸强度和屈服强度。结果：磨牙的平均破裂力为169.98 N (SD 32.32, CV 19.02%)，门牙的平均破裂力为222.67 N （SD 35.56, CV 15.97%）。门牙和磨牙在D0的变形与D7和D14有显著差异（p < 0.001）。结论：Tera Harz TC-85的机械稳定性建议每周更换矫正器，而不是每15天更换一次。直接3D打印不会减少所需对准器的总数，因为形状记忆会随着时间的推移而变得不稳定。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of the World Federation of Orthodontists DENTISTRY, ORAL SURGERY & MEDICINE-

CiteScore

3.80

自引率

4.80%

发文量