Torquing an upper central incisor with aligners--acting forces and biomechanical principles
| Autor: | Dietmar Kubein-Meesenburg, Wolfram Hahn, Antonia Zapf, Rudolf Gruber, Henning Dathe, Julia Fialka-Fricke, Susanne Fricke-Zech, Reza Sadat-Khonsari |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Dental Stress Analysis
Tooth Movement Techniques 0206 medical engineering Acrylic Resins Dentistry Orthodontics 02 engineering and technology Statistics Nonparametric Standard deviation 03 medical and health sciences 0302 clinical medicine Incisor Orthodontic Appliances Removable Maxilla medicine Humans Orthodontic Appliance Design Torque Statistical analysis Upper central incisor Physics business.industry Effective force 030206 dentistry 020601 biomedical engineering Biomechanical Phenomena Lift (force) medicine.anatomical_structure business Gingival margin |
| Zdroj: | The European Journal of Orthodontics. 32:607-613 |
| ISSN: | 1460-2210 0141-5387 |
| DOI: | 10.1093/ejo/cjq007 |
| Popis: | The forces delivered by aligners during torquing have still not been investigated. The purpose of this study was to measure the forces delivered to an upper central incisor during torquing with three different materials of the same thickness, and to describe the biomechanical principles of torquing with aligners. Five identical appliances were manufactured from each of three materials, all with a thickness of 1.0 mm (Ideal Clear®, Erkodur®, and Biolon®). An upper central incisor, as part of the measuring device, was torqued in defined steps in the vestibular and palatal directions with the respective appliance in place. For statistical analysis, the resulting forces, Fx (forces acting in the palatal and facial directions) and Fz (intrusive force as a side-effect) at a displacement of ±0.15 and ±0.8 mm from the tooth at the gingival margin were calculated. The mean Fx forces for ±0.15 mm displacement ranged from -1.89 N [standard deviation (SD) 0.48] to 0.11 N (SD 0.1). The mean Fz forces were between -0.97 N (SD 0.57) and -0.07 N (SD 0.22). The highest intrusive forces were measured during palatal displacement of the measuring tooth. An influence of direction of displacement on the levels of force was observed, especially for Fz at the greater displacement of ±0.8 mm. In relation to the intended amount of root movement during torquing, aligners tend to 'lift up' and therefore no effective force couple can be established for further root control. The force delivery properties are also influenced by the material used and the shape of the tooth. |
| Databáze: | OpenAIRE |
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