BIOMECHANICAL STABILITY OF ORTHODONTIC MINI-IMPLANTS: EXPERIMENTAL EVALUATION UNDER QUASI-STATIC LOADING AT A 90-DEGREE ANGLE
DOI:
https://doi.org/10.35220/2523-420X/2026.1.17Keywords:
orthodontic mini-implants, skeletal anchorage, biomechanics, ultimate load, stiffness, mechanical stability, bone model, cancellous bone, quasi-static loading, stressstrain state, orthodontic treatmentAbstract
In modern orthodontics, mini-implants are widely used as a reliable means of skeletal Anchorage, which allows you to effectively control the movement of teeth. At the same time, their biomechanical properties, in particular their behavior under load and stability in bone tissue, remain poorly understood. Of particular importance is the determination of the maximum loads and stiffness of the “mini-implant – bone tissue” system, which directly affects the clinical effectiveness of treatment. Purpose of the study. The purpose of the test was to determine the maximum pull-out load and stiffness of the “mini – implant-bone model” joint for a series of orthodontic mini-implants under quasi-static load, provided that they are installed at an angle of 90° to the direction of force application. Material and research method. The objects of the study were five samples of orthodontic mini-implants of various designs (No. 1–No. 5) made of TI–6AL–4V titanium alloy by mechanical processing. To simulate the mechanical properties of spongy bone tissue, each mini implant was placed in epoxy resin. The implant was fixed in the matrix so that the implant axis formed an angle of 90° with the direction of application of the load. After polymerization of the epoxy resin, samples were formed in the form of blocks with dimensions of approximately 20-25 mm in cross-section and 25-30 mm in height, in which the mini-implant was rigidly fixed at a given angle. The tests were carried out on a TIRATEST-2151 universal test machine with a maximum load of 5 kn. the load was applied to the mini-implant head using a metal wire and a special gripper. The epoxy block was installed on the lower support of the test machine. Conclusions. It is established that the obtained force – displacement diagrams (F–δ) do not fully reflect the real behavior of the system due to the complex nature of the load, so it is advisable to determine the moment of destruction based on the results of visual analysis. The linear part of the diagram can be used to determine the system stiffness. It was found that the stiffness of the “mini implant – bone model” system varies from 13.04 to 24.19 N/mm, depending on the implant design. The highest stiffness was recorded in 3 samples – 24.19 N/mm
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