Influence of the diameter and length of the mini-implant on the primary stability after loading with composite forces
10.3760/cma.j.issn.1002-0098.2013.01.010
- VernacularTitle:转矩对微螺钉种植体初期稳定性影响的三维有限元研究
- Author:
Ying-Juan LU
1
;
Shao-Hai CHANG
;
Hong WU
;
Yan-Song YU
;
Yu-Shan YE
Author Information
1. 中山大学孙逸仙纪念医院正畸科
- Keywords:
Torque;
Finite element analysis;
Orthodontic anchorage procedures;
Mini-screw
- From:
Chinese Journal of Stomatology
2013;48(1):37-40
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the influence of the diameter and length of the mini-implant on the primary stability after loading with composite forces (CF) which contained torque and horizontal forces (HF).Methods Ninety-six finite element models were established by the combination of mini-implant and bone,diameters (1.2 mm,1.6 mm,2.0 mm) and length (6 mm,8 mm,10 mm,12 mm).There were 12 sizes,each size corresponded with 8 models.Group HF (each size n =4) was loaded with 1.96 N horizontal force and Group CF (each size n =4) was loaded with composite force which contained 6 N · mm torque and 1.96 N horizontal force.The maximum displacement of mini-implant with different force directions,implant diameters and lengths were evaluated.Results The effect of force direction on the displacement related to diameter of mini-implant.The maximum displacement under load with HF respectively was changed with the changing of diameter[1.2 mm:(7.71 ±0.49) μm; 1.6 mm:(3.94 ±0.31) μm; 2.0 mm:(2.32 ±0.43) μm],which were smaller than the maximum displacement of Group CF[1.2 mm:(9.22 ±0.63) μm; 1.6 mm:(4.62±0.52) μm; 2.0 mm:(2.69 ±0.49) μm](P＜0.05).When diameter was 1.2 mm,the difference of the maximum displacement[(1.61 ± 0.22) μm]between Group HF and CF was more obvious than that when the diameter was 1.6 mm or 2.0 mm[(0.64 ±0.12),(0.49 ± 0.06) μ m] (P ＜ 0.05).Conclusions The composite force had unfavorable effect on the primary stability of the mini-implant.The diameter of the mini-implant had better be larger than 1.2 mm when the composite forces were applied.
