Analysis on the stress of the bone surrounding mini-implant with different diameters and lengths under torque

Lü, Yong; Chang, Shaohai; Ye, Jiantao; Ye, Yushan; Yu, Yijun

doi:10.3233/bme-151344

“…More and more experiments have proven that miniscrews could provide composite torque force to move teeth in three dimensions. 27,28 The stability of miniscrews is adversely affected by composite torque force and the miniscrews tend to rotate. Therefore, it is necessary for orthodontists to develop a new type of miniscrew anchorage which could accommodate the placement of a square wire and have good stability after bearing rotation torque forces.…”

Section: Discussionmentioning

confidence: 99%

Primary stability analysis of the torque-resistant orthodontic miniscrew anchorage

Ye

¹

,

Hao

²

,

He

³

et al. 2022

Advances in Mechanical Engineering

Self Cite

0

View full text Add to dashboard Cite

Though miniscrews are widely used as a temporary anchorage device, research focusing on the primary stability of miniscrew loading torque force is limited. This study is aimed to design a novel torque-resistant miniscrew used as orthodontic anchorage (TRO-screws) and to compare the difference of primary stability between TRO-screws and commercial miniscrew anchorage (COM-screws) using torque tests and resonance frequency analysis (RFA). Fresh swine ribs were cut into pieces of 20 mm × 13 mm × 11 mm, and each piece was implanted with one screw after a 1.5 mm-deep hole with a diameter of 1.0 mm was pre-drilled. There were 20 TRO-screws and 20 COM-screws. Maximum insertion torque (MIT) and maximum removal torque (MRT) were measured. The implant stability quotient (ISQ) was recorded parallel to and perpendicular to the long axis of teeth respectively. The measurement was repeated three times for each direction, and the ISQ values were averaged and recorded as the ISQpar, ISQper, and ISQm. The mean values of MIT for TRO-screws and COM-screws were 11.86±1.58 N cm and 10.36±1.42 N cm. The mean values of MRT for TRO-screws and COM-screws were 8.45±2.24 N cm and 6.76±1.78 N cm. The mean values of ISQ for TRO-screws and COM-screws were 61.80±2.9 and 58.15±2.98. These indicated that TRO-screws were more stable than COM-screws. We found that the primary stability of the TRO-screw was better than that of the COM-screw.

show abstract

“…As per the setting conditions of our previous experiments, bones are the class III bone from Lekholm and Zarb classification, and all the materials were homogeneous, isotropic, and linear elastic materials [ 24 – 29 ]. The biomechanical parameters of the material, including Young's modulus and Poisson's ratio of cortical bone, cancellous bone, and miniscrew, are presented in Table 1 .…”

Section: Methodsmentioning

confidence: 99%

“…The biomechanical parameters of the material, including Young's modulus and Poisson's ratio of cortical bone, cancellous bone, and miniscrew, are presented in Table 1 . They were set in previous studies, and they are the reference for our study [ 24 – 26 , 28 – 30 ].…”

Section: Methodsmentioning

confidence: 99%

Optimization Analysis of Two-Factor Continuous Variable between Thread Depth and Pitch of Microimplant under Toque Force

Ye

¹

,

Jiao

²

,

Fan

³

et al. 2022

Computational and Mathematical Methods in Medicine

Self Cite

2

0

View full text Add to dashboard Cite

Microimplant, an anchorage device, is widely applied in clinical orthodontic treatment. Since tooth torque is required to be controlled during orthodontic tooth movement, a novel microimplant needs to be developed to apply better torque force during orthodontic. In this study, the optimal value ranges of thread depth and pitch under toque force were studied for choosing microimplant with relevant value ranges in clinical design from biomechanical perspective. Finite element analysis (FEA) and optimization design technology were used for accessing the optimal value ranges of thread depth and pitch under toque force. Thread depth ( D ) (0.1 mm to 0.4 mm) and pitch ( P ) (0.4 mm to 1 mm) were used as continuous variables, with the other parameters as constant, and the optimal value ranges were obtained by analyzing the tangent slope and sensitivity of the response curve. When a torque force of 6 Nmm was applied on the microimplant, the maximum equivalent stress (Max EQV) of cortical bone and maximum displacements (Max DM) of microimplant were analysis indexes. When 0.55 mm ≤ P ≤ 1 mm , the Max EQV of cortical bone was relatively smaller with less variation range. When 0.1 mm ≤ D ≤ 0.35 mm , the Max DM of microimplant was relatively smaller with less variation range. So in conclusion, the initial stability of microimplants with pitch 0.55 mm ≤ P ≤ 1 mm and thread depth 0.1 mm ≤ D ≤ 0.35 mm was better with the torque force applied.

show abstract

“…Various study designs have been combined with FEA to evaluate MI design. Some studies have evaluated one or two design factors such as MI pitch, 19 presence of cervical threads, 11 exposure length of the MI, 20 taper, 21 MI length, MI diameter 15,22-25 and thread configuration. 26,27 Some have evaluated several design factors such as taper, thread depth, thread shape and diameter at the same time but the quantified significance of each design factor was not calculated.…”

Section: Introductionmentioning

confidence: 99%

Investigation of the optimal design of orthodontic mini-implants based on the primary stability: A finite element analysis

Haghighi

¹

,

Pouyafar

²

,

Navid

³

et al. 2019

J Dent Res Dent Clin Dent Prospects

View full text Add to dashboard Cite

Background. The design of an orthodontic mini-implant is a significant factor in determining its primary stability and its clinical success. The aim of this study was to measure the relative effect of mini-implant design factors on primary stability of orthodontic mini-implants. Methods. Thirty-two 3-dimensional assemblies of mini-implant models with their surrounding bone were generated using finite element analysis software. The maximum displacement of each mini-implant model was measured as they were loaded with a 2-N horizontal force. Employing Taguchi’s design of experiments as a statistical method, the contribution of each design factor to primary stability was calculated. As a result of the great effect of the upper diameter and length, to better detect the impact of the remaining design factors, another set of 25 models with a fixed amount of length and diameter was generated and evaluated. Results. The diameter and length showed a great impact on the primary stability in the first set of experiments (P<0.05). According to the second set of experiments, increased taper angle in the threaded and non-threaded area decreased the primary stability. There was also an optimum amount of 2.5 mm for threaded taper length beyond which the primary stability decreased. Conclusion. It is advisable to increase the diameter and length if primary stability is at risk. In the second place, a minimum amount of taper angle, both in the threaded and non-threaded area with an approximate proportion of 20% of threaded taper length to MI length, would be desirable for MIs with a moderate size.

show abstract

Analysis on the stress of the bone surrounding mini-implant with different diameters and lengths under torque

Cited by 6 publications

References 11 publications

Primary stability analysis of the torque-resistant orthodontic miniscrew anchorage

Primary stability analysis of the torque-resistant orthodontic miniscrew anchorage

Optimization Analysis of Two-Factor Continuous Variable between Thread Depth and Pitch of Microimplant under Toque Force

Investigation of the optimal design of orthodontic mini-implants based on the primary stability: A finite element analysis

Contact Info

Product

Resources

About