Dental Biomechanics
Pedram Akhlaghi; Setareh Khorshidparast; Gholamreza Rouhi; Hamidreza Barikani
Volume 15, Issue 2 , August 2021, , Pages 151-159
Abstract
Primary stability is the initial mechanical engagement of the implant with its neighboring bone, which can be assessed through in-vitro assessment of stiffness and the ultimate load of the bone-implant complex. Implantation and the following loading on an implant after implantation, could cause mechanical ...
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Primary stability is the initial mechanical engagement of the implant with its neighboring bone, which can be assessed through in-vitro assessment of stiffness and the ultimate load of the bone-implant complex. Implantation and the following loading on an implant after implantation, could cause mechanical damage in the peripheral bone, and subsequently, reduce the primary stability of the implant. This study aimed at finding the effects of damage induced in the bone through exerting compressive loading-unloading cycles on the primary stability of the bone-implant system. For this purpose, firstly, a cylindrical bone sample was extracted from the proximal part of a bovine tibia. After implantation and bone-implant preparation, a quasi-static compressive step-wise loading-unloading cycles, with a displacement rate of 0.0024 mm/s and displacement-controlled were applied to the bone-implant structure with the amplitudes of 0.04 mm to 1.28 mm. In each step, after unloading, µCT images was captured from the bone-implant sample. Finally, the stiffness of the structure in each step and ultimate load were obtained from the mechanical test. The distribution of plastic stain in the bone due to loading-unloading of the construct was calculated using digital volume correlation, through correlating the µCT images before and after each loading step. Results of this work showed that increasing the step-wise displacement amplitude from 0 to 0.96 mm caused a stiffness reduction of 40%, compared to the initial stiffness. Also, the digital volume correlation results showed that maximum plastic strain occurred in the neighboring bone in the crestal part of dental implant, and also increasing loading amplitude from 0.64 to 0.96 mm led to 1.5% increase in the maximum plastic strain. It is hoped that results of this kind of investigation can be helpful in optimizing the dental implants design, with the approach of increasing their stability.
