Influence of cortical bone thickness on miniscrew microcrack formation

Nguyen, Melissa V.; Codrington, John; Fletcher, Lloyd; Dreyer, Craig; Sampson, Wayne

doi:10.1016/j.ajodo.2016.12.028

Cited by 19 publications

(25 citation statements)

References 38 publications

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“…They are characterized by greater primary stability and a better BIC (bone implant contact); their insertion causes the creation of numerous bone fragments between the coils that can be interpreted as evidence that the bone is not compressed, but etched [ 28 ]. The miniscrews analyzed do not require predrilling, so they are under greater mechanical stress during the insertion [ 22 , 29 ]. Pre- and post-insertion morphostructural assessment performed with stereomicroscope and SEM showed no modification for all the miniscrews tested.…”

Section: Discussionmentioning

confidence: 99%

“…In addition, excessive insertion torque, heat at the border between the screw and the bone, and mechanical damage have been suggested to cause bone degeneration at the implant–tissue interface [ 21 ]. Nguyen et al stated that the ideal penetration torque range of 5–10 Ncm endorsed in the literature seems to be feasible only when the thickness of the cortical bone is between 0.5 and 1.0 mm [ 22 , 23 ].…”

Section: Introductionmentioning

confidence: 99%

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Drilling Capability of Orthodontic Miniscrews: In Vitro Study

et al. 2020

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The aims of this study were to assess the values and mechanical properties of insertion torque (IT) of steel miniscrews inserted in artificial bone blocks (Sawbones, Pacific Research Laboratories, Vashon, WA, USA) with different bone densities and to detect any scratches on the surface of the miniscrews after insertion. Forty self-drilling miniscrews (Leone S.p.A. ø 1.75 mm, L 8 mm) have been inserted into bone blocks that mimic different stability conditions (density: 20 PCF—pounds per cubic foot, 40 PCF, and 30 + 50 PCF with 2 mm and 4 mm of cortical bone). Before insertion and after removal, all miniscrews were inspected with a stereomicroscope 5x and a SEM to detect potential microscopic cracks. Using an electronic surgical motor (W&H Dentalwerk Bürmoos GmbH, Werner Bader Str. 1, 5111 Bürmoos, Austria), the maximum insertion torque value was registered. Stereomicroscope and SEM examination did not indicate any morphological and surface structural changes to the miniscrews, irrespective of the bone density they were inserted into. The findings showed that IT increased significantly with increasing bone density. In each artificial bone block, morphostructural analysis demonstrated the adequate mechanical properties of the self-drilling miniscrews. IT measurements indicated torque values between 6 and 10 Ncm for blocks with a density of 30 + 50 PCF, whereas the suggested values are between 5 and 10 Ncm.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Drilling Capability of Orthodontic Miniscrews: In Vitro Study

et al. 2020

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“…Various methods of imaging have been used previously to assess microdamage on the cortical bone surface. Some of the commonly used modalities are dental radiography, fluorescence imaging (Yadav et al, 2012), and histological studies (Nguyen et al, 2017). In studying microdamage, we need to bear in mind that the microcracks present in the cortical bone are a 3D entity and need to be studied as such.…”

Section: Comparisons Of Oct and μCt Images To Visualize Bone Microdamagementioning

confidence: 99%

Assessment of cortical bone microdamage following insertion of microimplants using optical coherence tomography: a preliminary study

Lakshmikantha

Ravichandran

Jeon

et al. 2018

J. Zhejiang Univ. Sci. B

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Objectives: The study was done to evaluate the efficacy of optical coherence tomography (OCT), to detect and analyze the microdamage occurring around the microimplant immediately following its placement, and to compare the findings with micro-computed tomography (μCT) images of the samples to validate the result of the present study. Methods: Microimplants were inserted into bovine bone samples. Images of the samples were obtained using OCT and μCT. Visual comparisons of the images were made to evaluate whether anatomical details and microdamage induced by microimplant insertion were accurately revealed by OCT. Results: The surface of the cortical bone with its anatomical variations is visualized on the OCT images. Microdamage occurring on the surface of the cortical bone around the microimplant can be appreciated in OCT images. The resulting OCT images were compared with the μCT images. A high correlation regarding the visualization of individual microcracks was observed. The depth penetration of OCT is limited when compared to μCT. Conclusions: OCT in the present study was able to generate high-resolution images of the microdamage occurring around the microimplant. Image quality at the surface of the cortical bone is above par when compared with μCT imaging, because of the inherent high contrast and high-resolution quality of OCT systems. Improvements in the imaging depth and development of intraoral sensors are vital for developing a real-time imaging system and integrating the system into orthodontic practice.

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“…However, in these papers, the diameter was determined with characteristics such as the Periotest value or the insertion torque, which are related to the screw’s stability and not related to the minimization of risk factors related to screw loosening (e.g., magnitude of microdamage). Furthermore, reproducibility in the experiments and extrapolation to clinics might be questionable because rodent or swine models were utilized [ 12 , 13 , 14 ].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Cortical Bone Microdamage and Primary Stability of Orthodontic Miniscrew Using a Human Bone Analogue

et al. 2021

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Orthodontic miniscrews have gained popularity; however, they have some drawbacks, including screw loosening that results from bone resorption caused by excess microdamage created during screw insertion. Pilot hole preparation through the cortical bone is considered beneficial to avoid such microdamage, while an overly large pilot hole impairs primary stability. Hence, we used a human bone analogue to evaluate the microdamage and primary stability to estimate the optimal pilot hole size that would minimize the screw loosening risk. Ti6Al4V orthodontic miniscrews and 1.0-mm-thick synthetic cortical bone pieces were prepared. Various compressive loads were applied in indentation tests to test pieces’ surfaces, and the microdamaged areas were confirmed as stress-whitening zones. Screw insertion tests were performed in which a miniscrew was inserted into the test pieces’ pilot hole with a diameter of 0.7–1.2 mm in 0.1-mm intervals, and the stress-whitening area was measured. The insertion and removal torque were also measured to evaluate primary stability. The stress-whitening areas of the 1.0–1.2 mm pilot hole diameter groups were significantly smaller than those of the other groups (p < 0.05), whereas the 0.9 and 1.0 mm pilot hole diameter groups showed higher primary stability than other groups. In conclusion, the bone analogue could be utilized to evaluate microdamage in cortical bones and the primary stability of miniscrews.

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Influence of cortical bone thickness on miniscrew microcrack formation

Cited by 19 publications

References 38 publications

Drilling Capability of Orthodontic Miniscrews: In Vitro Study

Drilling Capability of Orthodontic Miniscrews: In Vitro Study

Assessment of cortical bone microdamage following insertion of microimplants using optical coherence tomography: a preliminary study

Evaluation of Cortical Bone Microdamage and Primary Stability of Orthodontic Miniscrew Using a Human Bone Analogue

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