Effect of in vitro aging by water immersion and thermocycling on the mechanical properties of PETG aligner material

Ihssen, Benjamin; Willmann, Jan H.; Nimer, Amr; Drescher, Dieter

doi:10.1007/s00056-019-00192-8

Cited by 44 publications

(49 citation statements)

References 40 publications

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“…The orthodontic force was either too much, causing root resorption, or too small, which led to prolonged treatment period. One particular study explored the value of clear aligner therapy using the force value of 0.0 mm, 0.1 mm and 0.2 mm three different tooth movements, and found that the orthodontic force value changed with the amount of activation as follows: the force of 0.0 mm activation < the force of 0.1 mm activation< the force of 0.2 mm activation, and provided the foundation for different activation aligners therapy [7,19]. In the current study, we examined the effect of three different activations, 0.0 mm, 0.1 mm and 0.2 mm on the orthodontic force properties using AS immersion, and our ndings were in line with those reported in Adham Skaikpr's papers.…”

Section: Discussionmentioning

confidence: 99%

The Force Effects of Two Types of Polyethylene Terephthalate Glyc-olmodified Clear Aligners Immersed in Artificial Saliva

Xiang¹,

Wang²,

Wu³

et al. 2020

Preprint

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Numerous factors can influence the force exerted by clear aligners teeth. This study aimed to investigate the stability of the force delivered by two different material appliances. 90 clear aligners with 2 materials and three different activations were designed and fabricated. Then, a device was employed to measure the force generated by the two types of PET-G material appliances immersed in artificial saliva for 0, 3, 7, 10, 14 days. Scanning electron microscopy was applied to observe the morphologic alterations on the aligner surfaces, respectively. The forces generated by different activation appliance exhibited differently, 0.0 mm < 0.1 mm < 0.2 mm. In addition, increasing the immersion times and the orthodontic force also decreased , but the forces decreased differently. Compared with the forces of conventional PETG appliances with 0.20 mm activation, the modified PETG appliances with the same activation exhibited significantly higher mean force. When comparing the mean force for modified PETG appliances after 10 and 14 days with conventional PETG appliances, the delivery forces exhibited significant differences (P<0.05). The force delivered by both materials decreased obviously following artificial saliva immersion, and the force generated by modified aligners exhibited better stability than conventional aligners.

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Section: Discussionmentioning

confidence: 99%

The Force Effects of Two Types of Polyethylene Terephthalate Glyc-olmodified Clear Aligners Immersed in Artificial Saliva

Xiang¹,

Wang²,

Wu³

et al. 2020

Preprint

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“…Low stiffness, good defomability, dimensional and environment stability as well as high biocomptability are the conditions that must met by the polymers to be used. The invisible orthodontic force, derived from the deformation and elasticity of aligners, depends on the chemical composition, arrangement and entanglement of the polymer chains, thickness, and the clinical protocol [1][2][3]5,17,[32][33][34][35][36][37][38]. The ideal clear aligner material must deliver sufficient machanical force to induce an orthodontic movement in a highly controlled manner and simultaneously preventing a damage of the surrounding perodontal Tissues [37].…”

Section: Review Articlementioning

confidence: 99%

“…The decrease in elastic modulus is due to an increase in temperature and water absorbtion. It is accompanied by the decrease in the initial forces that the aligner applies in the early phase after intraoral use [34].…”

Section: Elastic Modulusmentioning

confidence: 99%

Effect of Dental Thermoplastic Materials on the Clinical Effectiveness of Clear Aligner

L¹,

Gerngro²

2021

Austin J Dent

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Objective: The aim of this review is to evaluate the influence of chemical and mechanical material properties properties on the effectiveness of the clinical treatment with a clear aligner. Methods: A systematic literature study of recent and most relevant publications in this field has been performed to identify the most important material effects on the clinical effectiveness of clear aligners. Results: Clear aligner devices have found a wide application in orthodontics. The development of new materials which are metal-free and the CAD/CAM engineering technique make it possible to treat the various kinds of malocclusion. Patients prefer clear aligners because of their aesthetics and comfort. The thermoplastic materials have inherent advantages: excellent aesthetic appearance, simple to be used and superior formability. Various thermoplastic materials are being developed for manufacturing of clear aligners. The mechanical properties of polymers play a crucial role in the effectiveness of the therapeutic treatments. Therefore, the elasticity, dimension and environment stability as well as biocompatibility are the main conditions, which the polymer must meet for being used in clear aligners. Conclusions: The main advantages of clear aligner in comparison to metal or ceramic devices is their excellence aesthetic with better patient acceptance and a general better quality of life. From a clinical point of view, the treatment with clear aligner causes less pain compared to a traditional treatment and also reduce the damage to the gingiva and perodontal tissue. The clinical success of the clear aligner therapy strongly depends on the properties of the used aligner materials. Significance: The use of thermoplastic materials for orthodontic tooth movements requires a better understanding of the material properties for selecting the optimal material and design.

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“…Several studies reported that mechanical and physical properties of orthodontic aligner materials may change after thermoforming, cyclic mechanical loading and/or thermocycling processes as well as after clinical use [3]. Thus mechanical properties should be determined after thermoforming and under the influence of thermocycling and cyclic loading [2,8,10,21].…”

Section: Introductionmentioning

confidence: 99%

Variation of the modulus of elasticity of aligner foil sheet materials due to thermoforming

et al. 2021

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Objective Investigate and compare the mechanical properties of different aligner materials before and after deep drawing and determine differences in the mechanical properties after thermoforming. Materials and methods Four aligner film sheets from three manufacturers (Duran Plus® [Scheu Dental, Iserlohn, Germany]; Zendura® [ClearCorrect, Bay Materials LLC, Fremont, CA, USA]; Essix ACE® and Essix® PLUS™ [Dentsply Sirona Deutschland, Bensheim, Germany]) were tested in 3‑point bending with support distances of 8, 16, and 24 mm. Dimension of the specimens was 10 × 50 mm2. Two groups each were tested: (1) 10 specimens were investigated in the as-received state (before thermoforming), (2) 10 specimens were deep drawn on a master plate with cuboids of the dimension 10 × 10 × 50 mm3. Then, specimens were cut out of the upper side and lateral walls and were measured in 3‑point bending. Forces and reduction in thickness were measured and corrected theoretical forces of drawn sheets after thickness reduction as well as Young’s modulus were calculated. Results At a support distance of 8 mm and a displacement of 0.25 mm Essix® PLUS™, having the highest thickness in untreated state, showed highest forces of 28.2 N, followed by Duran Plus® (27.3 N), Essix ACE® (21.0 N) and Zendura® (19.7 N). Similar results were registered for the other distances (16, 24 mm). Thermoforming drastically reduced thickness and forces in the bending tests. Forces decreased to around 10% or less for specimens cut from the lateral walls. Young’s modulus decreased significantly for deep drawn foil sheets, especially for Essix® PLUS™. Conclusions Three-point bending is an appropriate method to compare different foil sheet materials. Young’s modulus is significantly affected by thermoforming.

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Effect of in vitro aging by water immersion and thermocycling on the mechanical properties of PETG aligner material

Cited by 44 publications

References 40 publications

The Force Effects of Two Types of Polyethylene Terephthalate Glyc-olmodified Clear Aligners Immersed in Artificial Saliva

The Force Effects of Two Types of Polyethylene Terephthalate Glyc-olmodified Clear Aligners Immersed in Artificial Saliva

Effect of Dental Thermoplastic Materials on the Clinical Effectiveness of Clear Aligner

Variation of the modulus of elasticity of aligner foil sheet materials due to thermoforming

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