scholarly journals Effects of the Taper Shape, Dual-Thread, and Length on the Mechanical Properties of Mini-Implants

2009 ◽  
Vol 79 (5) ◽  
pp. 908-914 ◽  
Author(s):  
Young-Kyun Kim ◽  
Yoon-Ji Kim ◽  
Pil-Young Yun ◽  
Jong-Wan Kim

Abstract Objective: To analyze the mechanical effects of the length and the various shapes such as cylindrical shape, taper shape, and dual-thread shape on the insertion and removal torque of mini-implants. Materials and Methods: Mini-implants (diameter 1.6 mm and length 6 mm and 8 mm) consisting of cylindrical, taper, and dual-thread groups were inserted and removed in Sawbones while measuring the torque and time. Mechanical analysis was done of maximum insertion torque (MIT), maximum removal torque (MRT), torque ratio (TR; MRT/MIT), insertion angular momentum (IAM), removal angular momentum (RAM), and time of MIT. Measurements were statistically evaluated to analyze any differences of shapes and lengths. Results: The cylindrical shape had the lowest MIT and MRT in each length. Although taper shape showed the highest MIT in each length, dual-thread shape showed significantly higher MRT, TR, and RAM in each length (P < .05). Dual-thread groups showed a gentle increase of insertion torque and a gentle decrease of removal torque in contrast to the other shape groups. However, it had higher IAM and time of MIT. The long length group showed significantly higher measurements except for TR. Conclusions: Dual-thread shape provided better mechanical stability with high removal torque on the broad range than other shapes. However, dual-thread shape may need improvement for reducing the long insertion time to decrease the stress to the surrounding tissue.


2013 ◽  
Vol 83 (6) ◽  
pp. 1009-1014 ◽  
Author(s):  
Il-Sik Cho ◽  
Sang-Ho Baek ◽  
Young Ho Kim

ABSTRACT Objective: To investigate the effects of wobbling angle on the stability measures of orthodontic mini-implants (OMIs) during insertion and removal procedures in artificial bone blocks. Materials and Methods: A total of 36 OMIs (self-drilling type, cylindrical shape, 7 mm in length, 1.45 mm in diameter) were allocated into three groups according to the amount of wobbling angle (W-0°, W-2°, and W-4° groups; N = 12 per group). The OMIs were installed and subsequently removed from artificial bone blocks (Sawbone) using a driving torque tester with a uniform speed of 28 rpm. Insertion peak time (IPT), maximum insertion torque (MIT), total insertion energy (TIE), near-peak insertion energy (NPIE), maximum removal torque (MRT), and near-peak removal energy (NPRE) were measured. Results: The W-4° group showed the longest IPT and highest TIE and NPIE, followed by the W-2° and W-0° groups (W-0° < W-2° < W-4°, all P < .001). The W-2° and W-4° groups showed significant increase in MIT compared with the W-0° group (W-0° < [W-4°,W-2°]; P < .001). Although there was no significant difference in NPRE among the three groups, the W-4° group showed a decrease in MRT compared with the W-0° and W-2° groups (W-4° < {W-2°,W-0°]; P < .05). Although the W-4° group showed a 14.5% (2.9 Ncm) increase in MIT compared with the W-0° group, there was only a 6% (1.3 Ncm) decrease in MRT from the W-0° group to the W-4° group. Conclusion: Slight wobbling during the OMI insertion procedure may be acceptable in terms of the stability measures of OMIs during insertion and removal procedures.



2014 ◽  
Vol 2 (2) ◽  
pp. 169
Author(s):  
Fabiana Padovan Di Lello ◽  
Flávia Regina Vergamine Salles Sgarbi ◽  
Eloisa Marcantonio Boeck ◽  
Nadia Lunardi ◽  
Rodolfo Jorge Boeck Neto

AIM: The aim of this work was evaluate the insertion and removal torque for orthodontic mini-implants inserted in different inclination. MATERIALS AND METHODS: Ten self-drilling mini-implants from the brand SIN (Sistema de Implantes Nacional, São Paulo/SP, Brazil), and the surgical kit for their insertion were used. Two plaques of synthetic bone of 120 mm x 170 mm x 41,5 mm were used (Sawbones, Pacific Research Laboratories Inc, Vashon, Wash), with 1,5 mm height, simulating the cortical bone (density 40 pcf) and 40 mm simulating the medullary bone (density 15 pcf). In each block, five areas were demarcated for each mark, totalizing ten areas. The ten mini-implants were inserted by the same operator, previously calibrated; five of them at 900 and five at 600, using the manual key kit. After the insertion of all the mini-implants, the final threading and the reading of insertion torque value were carried out with a manual torque wrench digital Lutron TQ-8800 (Lutron Electronic Enterprise Co., Ltd, Taipei, Taiwan) until the trans-mucosal profile achieve the cortical bone. The maximum insertion torque value was registered in N/cm. After all the implants inserted, the measurement of removal torque was started, performed in the same way of insertion, but in the opposite anticlockwise. The results were submitted to the T test (parametric) and to a Mann-Whitney test (non-parametric). RESULTS: The results demonstrated that the insertion torque was lower than the removal one in both insertion degrees, with statistically significance. Despite insertion torque at 90 degrees had been lightly higher than that inserted at 60 degrees, they were not statistically significant. CONCLUSION: In view of the results, it was possible conclude that insertion at 60º angulation does not offer advantages to the primary stability for orthodontic mini-implants.



2009 ◽  
Vol 79 (5) ◽  
pp. 899-907 ◽  
Author(s):  
Seong-Hun Kim ◽  
Shin-Jae Lee ◽  
Il-Sik Cho ◽  
Seong-Kyun Kim ◽  
Tae-Woo Kim

Abstract Objective: To test the hypothesis that there is no difference in the stability and resistance to rotational moments of early loaded sandblasted and acid-etched (SLA) mini-implants and those of machined-surface implants of the same size and shape. Materials and Methods: A randomized complete block design was used in 12 skeletally mature male beagle dogs. Ninety-six orthodontic mini-implants were tested. Two types of implants were used: some had SLA surface treatment and some had machined surfaces without coating. After 3 weeks of healing, rotational moments of 150 g were applied. The success rates, maximum torque values, angular momentum, and total energy absorbed by the bone were compared. All values were subjected to mixed-model analysis to evaluate the influence of surface treatment, rotational force direction, and site of implantation. Results: The maximum insertion torque and angular momentum of SLA implants were significantly lower than those of machined implants (P = .034, P = .039). The SLA implants had a significantly higher value for total removal energy than the machined implants (P = .046). However, there were no significant differences in total insertion energy, maximum removal torque, and removal angular momentum between the 2 groups. There was no significant difference between clockwise and counterclockwise rotation in all measurements. Conclusion: SLA mini-implants showed relatively lower insertion torque value and angular momentum and higher total energy during removal than the machined implants, suggesting osseointegration of the SLA mini-implant after insertion.



2015 ◽  
Vol 20 (5) ◽  
pp. 35-42
Author(s):  
Giselle Naback Lemes Vilani ◽  
Antônio Carlos de Oliveira Ruellas ◽  
Carlos Nelson Elias ◽  
Cláudia Trindade Mattos

Objective: To compare in vivo orthodontic mini-implants (MI) of smooth (machined) and rough (acid etched) surfaces, assessing primary and secondary stability.Methods:Thirty-six (36) MI were inserted in the mandibles of six (6) dogs. Each animal received six (6) MI. In the right hemiarch, three (3) MI without surface treatment (smooth) were inserted, whereas in the left hemiarch, another three (3) MI with acid etched surfaces (rough) were inserted. The two distal MI in each hemiarch received an immediate load of 1.0 N for 16 weeks, whereas the MI in the mesial extremity was not subject to loading. Stability was measured by insertion and removal torque, initial and final mobility and by inter mini-implant distance.Results:There was no statistical behavioral difference between smooth and rough MI. High insertion torque and reduced initial mobility were observed in all groups, as well as a reduction in removal torques in comparison with insertion torque. Rough MI presented higher removal torque and lower final mobility in comparison to smooth MI. MI did not remain static, with displacement of rough MI being smaller in comparison with smooth MI, but with no statistical difference.Conclusions:MI primary stability was greater than stability measured at removal. There was no difference in stability between smooth and rough MI when assessing mobility, displacement and insertion as well as removal torques.



2014 ◽  
Vol 44 (4) ◽  
pp. 177 ◽  
Author(s):  
Višnja Katić ◽  
Ervin Kamenar ◽  
David Blažević ◽  
Stjepan Špalj


Prosthesis ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 76-86
Author(s):  
Luca Comuzzi ◽  
Margherita Tumedei ◽  
Adriano Piattelli ◽  
Giovanna Iezzi

(1) Background: The aim of the present in vitro investigation was to evaluate, on polyurethane sheets, two different drilling techniques for dental implant positioning using osteocondensing burs compared to a standard type protocol. (2) Methods: Three different implant designs (Implacil De Bortoli UN III 4 × 10 mm, Restore RBM 4 (HEX) × 10 mm; Implacil De Bortoli UN II 4 × 10 mm) were evaluated (test implant (osteocondensing drills) and control implant (standard drills)). The insertion torque (IT), the removal torque (RT) and the resonance frequency analysis (RFA) values of test and control implants inserted in different size and different density polyurethane foam models were compared for 120 experimental sites. Accordingly, 120 experimental holes were produced in different PCF polyurethane foams: 60 sites were produced in 10 PCF sheets and 60 sites in 10 PCF sheets with an additional 1 mm layer of 30 PCF. (3) Results: The IT, removal torque and RFA values were significantly higher for both of the evaluated implants, in the sites prepared with the osteocondenser drills when compared to sites prepared with standard drills (p < 0.05). The UNII and UN III showed significantly higher stability compared to the HEX implant; these differences increased drastically in the 10 PCF Polyurethane Block with the additional 1 mm cortical layer (p < 0.05). (4) Conclusions: The outcome of this investigation suggested a possible clinical application of osteocondensing burs in case of reduced bone quality and quantity in the posterior maxilla.



2011 ◽  
Vol 81 (5) ◽  
pp. 776-782 ◽  
Author(s):  
Ki-Ho Park ◽  
Eun-Man Lee ◽  
Seung-il Shin ◽  
Seong-Hun Kim ◽  
Young-Guk Park ◽  
...  

Abstract Objective: To compare the effect of clockwise and counterclockwise torque on the primary stability of a mini-implant with a lever-arm–shaped upper structure. Materials and Methods: Twenty-four white rabbits were used for this study. Two screw-type mini-implants were placed in each tibia. In all, 96 screws were inserted. Two weeks later, a 2-N force was applied to the mini-implants without an upper structure in eight rabbits (control group). The mini-implants of the other 16 rabbits were loaded with an upper structure (experimental group). In the experimental group, the two left mini-implants were loaded in a clockwise direction (CW group) and the two right implants were loaded in a counterclockwise direction (CCW group). The rabbits were sacrificed at 1 week or 8 weeks after loading in both control and experimental groups. The removal torque value (RTV) was measured in 15 of 16 mini-implants in each group and the remaining implant was processed for histologic examination. Results: At 1 week there were no significant differences in the mean RTV between the control, CW, and CCW groups. At 8 weeks, the RTV was higher in the control and experimental groups than in the respective 1-week groups. At 8 weeks, there were no significant differences in the RTV between the control and CW groups, but the CCW group showed a lower RTV. Conclusions: CCW torque can decrease the stability of a mini-implant, whereas a CW torque has no effect.



Author(s):  
Bruno Di Leonardo ◽  
Björn Ludwig ◽  
Jörg Alexander Lisson ◽  
Luca Contardo ◽  
Rossano Mura ◽  
...  


Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5615
Author(s):  
Jie Jin ◽  
Gi-Tae Kim ◽  
Jae-Sung Kwon ◽  
Sung-Hwan Choi

Miniscrews have gained recent popularity as temporary anchorage devices in orthodontic treatments, where failure due to sinus perforations or damage to the neighboring roots have increased. Issues regarding miniscrews in insufficient interradicular space must also be resolved. This study aimed to evaluate the primary stability of miniscrews shorter than 6 mm and their feasibility in artificial bone with densities of 30, 40, and 50 pounds per cubic foot (pcf). The primary stability was evaluated by adjusting the intrabony miniscrew length, based on several physical properties: maximum insertion torque (MIT), maximum removal torque (MRT), removal angular momentum (RAM), horizontal resistance, and micromotion. The MIT and micromotion results demonstrated that the intrabony length of a miniscrew significantly affected its stability in low-density cortical bone, unlike cases with a higher cortical bone density (p < 0.05). The horizontal resistance, MRT, and RAM were affected by the intrabony length, regardless of the bone density (p < 0.05). Thus, the primary stability of miniscrews was affected by both the cortical bone density and intrabony length. The effect of the intrabony length was more significant in low-density cortical bone, where the implantation depth increased as more energy was required to remove the miniscrew. This facilitated higher resistance and a lower risk of falling out.



2019 ◽  
Vol 9 (8) ◽  
pp. 1673 ◽  
Author(s):  
Li-Ying Liu ◽  
Yang Ding ◽  
Bo Zhou ◽  
Ning-Ning Jia ◽  
Kuan Wang ◽  
...  

Na2Ti7O15 (NTO) can be selected as candidate anode for high-performance sodium-ion batteries (SIBs). However, there are few reports of research on the mechanical properties of low-dimensional NTO, which is important for the stability of SIBs. In this work, by using the one-step hydrothermal method, NTO nanowires (NWs) with good orientation were prepared successfully. The transmission electron microscopy (TEM) and selected area electron diffraction (SAED)showed that the NTO NWs had a good aspect ratio and dispersion, with lengths over 20 μm. Further microstructure analysis showed that the nanowires grew along the (020) direction, and there were some "stripe" structures along the growing direction, which provides a good tunnel structure for Na ion channels. Further, the in situ mechanical analysis showed that the NTO NWs had excellent elastic deformation characteristics and mechanical structural stability. In addition, the NTO NWs also showed a good gas sensitivity to NO and NH3. Our results showed that the prepared NTO nanowires with a stripe tunnel oriented-structure and excellent mechanical properties may have a potential application in SIBs or other wearable sensor devices.



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