Abstract
TITLE: THE BEHAVIOR OF DIGITALLY FABRICATED FIXED RETAINERS IN RELATION TO DIFFERENT MATERIAL PROPERTIES. A THREE-DIMENSIONAL FINITE ELEMENT ANALYSIS
AIM: The purpose of this study is to investigate the influence of material properties used to fabricate retainers on physiologic root movement.
MATERIALS AND METHOD: A finite element model of six lower teeth with simulated roots was created from an intraoral scan. A 0.012" x 0.012" (0.3 mm x 0.3 mm) flat square retainer was designed. The apices of all teeth were constrained in the buccal-lingual and mesial-distal directions. The apices of the central incisors were additionally constrained in the vertical axis. A single force of 100N was applied vertically on tooth 43 to simulate an occlusal force. Different moduli of elasticity were assigned to the retainer to represent four different materials: martensitic Nitinol (m-NiTi @ 28 GPa), austenitic Nitinol (a-NiTi @ 83 GPa), beta-Titanium (β-Ti @ 115 GPa) and Stainless Steel (SS @ 220 GPa). The displacements of the teeth were calculated and examined.
RESULTS: For m-NiTi, the vertical displacement of 43 was more than double compared to SS (1.33 and 0.61 mm, respectively). In case of β-Ti, the vertical displacement was 0.73 mm. The upward displacement of 33, due to the seesaw effect of the retainer, ranged from 0.18 mm for SS to 0.21 mm for m-NiTi.
CONCLUSIONS: The higher the modulus of elasticity, the less physiological root movement is seen on the loaded side. However, the upward movement of the canine on the contralateral side of the retainer was almost independent of the stiffness of the retainer.
AIM: The purpose of this study is to investigate the influence of material properties used to fabricate retainers on physiologic root movement.
MATERIALS AND METHOD: A finite element model of six lower teeth with simulated roots was created from an intraoral scan. A 0.012" x 0.012" (0.3 mm x 0.3 mm) flat square retainer was designed. The apices of all teeth were constrained in the buccal-lingual and mesial-distal directions. The apices of the central incisors were additionally constrained in the vertical axis. A single force of 100N was applied vertically on tooth 43 to simulate an occlusal force. Different moduli of elasticity were assigned to the retainer to represent four different materials: martensitic Nitinol (m-NiTi @ 28 GPa), austenitic Nitinol (a-NiTi @ 83 GPa), beta-Titanium (β-Ti @ 115 GPa) and Stainless Steel (SS @ 220 GPa). The displacements of the teeth were calculated and examined.
RESULTS: For m-NiTi, the vertical displacement of 43 was more than double compared to SS (1.33 and 0.61 mm, respectively). In case of β-Ti, the vertical displacement was 0.73 mm. The upward displacement of 33, due to the seesaw effect of the retainer, ranged from 0.18 mm for SS to 0.21 mm for m-NiTi.
CONCLUSIONS: The higher the modulus of elasticity, the less physiological root movement is seen on the loaded side. However, the upward movement of the canine on the contralateral side of the retainer was almost independent of the stiffness of the retainer.
| Originalsprog | Engelsk |
|---|---|
| Publikationsdato | 17 jun. 2018 |
| Antal sider | 1 |
| Status | Udgivet - 17 jun. 2018 |
| Begivenhed | 94th EOS 2018 European Orthodontic Society Congress - Edinburgh, Storbritannien Varighed: 17 jun. 2018 → 21 jun. 2018 http://www.eos2018.com/ |
Konference
| Konference | 94th EOS 2018 European Orthodontic Society Congress |
|---|---|
| Land/Område | Storbritannien |
| By | Edinburgh |
| Periode | 17/06/2018 → 21/06/2018 |
| Internetadresse |