The carrying of artificial teeth attached to an orthodontic appliance while moving teeth (Clinic)

Almost all orthodontic wires suffer from corrosion as they are intra-orally engaged. This chemical structure alteration appears on the surface of these wires, surface topography can be easily visualised with scanning electron microscope method. The aim of our study was to assess the intraoral corrosion of the retrieved orthodontic Ni-Ti archwires. Archwire retrieval procedure yielded approximately 30 retrieved wires, placed intra-orally for 1-5 months. SEM analysis was performed and surface changes were interpreted. Our SEM results showed, that surface corrosion and pitting can be seen on the surface of retrieved Ni-Ti wires, the depth of corrosion depends on the time wires have been engaged in the oral cavity. With regards of metal liberation consequently surface corrosion, practitioners should be avare of these chemical changes which can affect the resistence of the orthodontic appliance and patient health.

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Numerical Analysis of the Bond Strength between Two Methacrylic Polymers by Surface Modification

Materials ◽

10.3390/ma14143927 ◽

2021 ◽

Vol 14 (14) ◽

pp. 3927

Author(s):

Joanna Taczała ◽

Katarzyna Rak ◽

Jacek Sawicki ◽

Michał Krasowski

Keyword(s):

Numerical Analysis ◽

Bond Strength ◽

Angular Position ◽

Fem Analysis ◽

Groove Depth ◽

Chemical Reagent ◽

Shear Process ◽

3D Geometry ◽

The Right ◽

Artificial Teeth

The creation of acrylic dentures involves many stages. One of them is to prepare the surfaces of artificial teeth for connection with the denture plates. The teeth could be rubbed with a chemical reagent, the surface could be developed, or retention hooks could be created. Preparation of the surface is used to improve the bond between the teeth and the plate. Choosing the right combination affects the length of denture use. This work focuses on a numerical analysis of grooving. The purpose of this article is to select the shape and size of the grooves that would most affect the quality of the bond strength. Two types of grooves in different dimensional configurations were analyzed. The variables were groove depth and width, and the distance between the grooves. Finally, 24 configurations were obtained. Models were analyzed in terms of their angular position to the loading force. Finite element method (FEM) analysis was performed on the 3D geometry created, which consisted of two polymer bodies under the shear process. The smallest values of the stresses and strains were characterized by a sample with parallel grooves with the grooving dimensions width 0.20 mm, thickness 0.10 mm, and distance between the grooves 5.00 mm, placed at an angle of 90°. The best dimensions from the parallel (III) and cross (#) grooves were compared experimentally. Specimens with grooving III were not damaged in the shear test. The research shows that the shape of the groove affects the distribution of stresses and strains. Combining the selected method with an adequately selected chemical reagent can significantly increase the strength of the connection.

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Identification of bone morphogenetic protein 4 in the saliva after the placement of fixed orthodontic appliance

Progress in Orthodontics ◽

10.1186/s40510-021-00364-6 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Lovorka Grgurevic ◽

Ruder Novak ◽

Grgur Salai ◽

Vladimir Trkulja ◽

Lejla Ferhatovic Hamzic ◽

...

Keyword(s):

Growth Factor ◽

Bone Morphogenetic Protein ◽

Bone Remodeling ◽

Small Sample ◽

Central Position ◽

Published Data ◽

Bone Morphogenetic Protein 4 ◽

Orthodontic Appliance ◽

Morphogenetic Protein ◽

Fixed Orthodontic Appliance

Abstract Background This study was conducted in order to explore the effects of orthodontic tooth movement (OTM) on the changes of salivary proteome. This prospective observational pilot study recruited 12 healthy teenage boys with malocclusion treated with a fixed orthodontic appliance and 6 appropriate control participants. Saliva samples were collected a day before and at 0, 2, 7, and 30 days after initialization of treatment, corresponding to the initial, lag, and post-lag phases of OTM. Pooled samples were analyzed by liquid chromatography-mass spectrometry, ELISA, and Western blotting. To date, there is no published data on the presence of BMP molecules or their antagonists in the saliva or in the gingival cervical fluid related to orthodontic conditions. Results A total of 198 identified saliva proteins were classified based on their functional characteristics. Proteins involved in bone remodeling were observed exclusively 30 days post appliance placement, including bone morphogenetic protein 4 (BMP4), a BMP antagonist BMP-binding endothelial regulator, insulin-like growth factor-binding protein 3, cytoskeleton-associated protein 4, and fibroblast growth factor 5. Based on the analysis of protein interactions, BMP4 was found to have a central position in this OTM-related protein network. Conclusions The placement of a fixed orthodontic appliance induced occurrence of proteins involved in bone remodeling in the saliva at a time corresponding to the post-lag period of OTM. Limitations of this study include a relatively small sample size, limited time of monitoring patients, and the lack of interindividual variability assessment.

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Orthodontic Aligner Incorporating Eucommia ulmoides Exerts Low Continuous Force: In Vitro Study

Materials ◽

10.3390/ma13184085 ◽

2020 ◽

Vol 13 (18) ◽

pp. 4085

Author(s):

Sayuri Inoue ◽

Satoshi Yamaguchi ◽

Hiroshi Uyama ◽

Takashi Yamashiro ◽

Satoshi Imazato

Keyword(s):

Water Immersion ◽

In Vitro Study ◽

Nickel Titanium ◽

Orthodontic Appliances ◽

Orthodontic Appliance ◽

Measuring Device ◽

Orthodontic Force ◽

Custom Made ◽

Titanium Wire

The aim of this study was to investigate the orthodontic force exerted by thermoplastic orthodontic appliances incorporating Eucommiaulmoides in terms of usefulness as the aligner-type orthodontic device. Erkodur, Essix C+®, Eucommia elastomer, and edgewise brackets were used (n = 3, each; thickness = 1.0 mm, each). The orthodontic force on the upper right incisor was measured every 24 h for two weeks using a custom-made measuring device. The force of the Eucommia elastomer (4.25 ± 0.274 N) and multi bracket system (5.32 ± 0.338 N) did not change from the beginning to the end (p > 0.01). The orthodontic force exerted by the Eucommia elastomer was lower than that of the multi-bracket orthodontic appliance from the beginning to the end. The force of Erkodur significantly decreased from the beginning to 24 h (6.47 ± 1.40 N) and 48 h (3.30 ± 0.536 N) (p < 0.01). The force of Essix C+® significantly decreased from the beginning (13.2 ± 0.845 N) to 24 h (8.77 ± 0.231 N) (p < 0.01). The thermoplastic orthodontic appliance made of Eucommia elastomer continuously exerted a constant orthodontic force for two weeks under water immersion conditions. The orthodontic force of Eucommia elastomer was found to be similar to the orthodontic force exerted by the multi-bracket orthodontic appliance with 0.019 × 0.025 in nickel–titanium wire. These results suggest that the Eucommia elastomer has possibly become one of the more useful materials to form thermoplastic orthodontic appliance exerting low continues orthodontic force.

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