Acta of bioengineering and biomechanics最新文献

The constantly growing need for the use of implants in osteotomy is mainly due to the aging population and the need for long-term use of this type of biomaterials. Improving implant materials requires the selection of appropriate functional properties. Currently used titanium (Ti) alloys, such as Ti6Al4V and Ti6Al7Nb, are being replaced by materials with better biocompatibility, such as vanadium (V) or niobium (Nb), allowing for creation of the so-called new generation alloys. These new alloys, with the incorporation of zirconium (Zr), iron, and tantalum, possess Young's modulus close to that of a bone, which further improves the improves the biomaterial's. biocompatibility. This article describes the atomic layer deposition (ALD) method and its possible applications in the new generation of titanium alloys for biomedical applications. Also, the exemplary results of tin oxide (SnO2) thin coatings deposited by ALD and physical vapor deposition (PVD) methods are presented. This study aimed to evaluate the physicochemical properties of a Ti13Nb13Zr alloy used for elements in the skeletal system. As the temperature and the number of cycles vary, the results demonstrate that the surface area of the samples changes. The uncoated Ti13Nb13Zr alloy exhibits hydrophilic properties. However, all coated specimens improve in this respect and provide improved clinical results. after the applied modification, the samples have a smaller contact angle, but still remain in the range of 0-90°, which makes it possible to conclude that their nature remains hydrophilic. Coating the specimens decreased the mineralization risk of postoperative complications. As a result, the biomaterials demonstrated improved effectiveness, decreased complication indicators, and improved patient well-being.

The drag in walking, running and sprinting locomotion can be assessed by analytical procedures and experimental techniques. However, assessing the drag variations by the above-mentioned types of locomotion were not found using computational fluid dynamics (CFD). Thus, the aim of this study was two-fold: (1) to assess the aerodynamics of human walking, running and sprinting by CFD technique; 2) compare such aerodynamic characteristics between walking and running. Three 3D models were produced depicting the walking, running and sprinting locomotion techniques, converted to computer aided design models and meshed. The drag varied with locomotion type. Walking had the lowest drag, followed-up by running and then sprinting. At the same velocities, the drag was larger in walking than in running and increased with velocity. In conclusion, drag varied with locomotion type. Walking had the lowest drag, followed-up by running and then sprinting. At the same velocities, the drag was larger in walking than in running and increased with velocity.

Purpose: The aim of this study was to evaluate the mechanical stimuli transfer at the bone-implant interface via stress and strain energy density transfer parameters. This study also aimed to investigate the effect of different implant stiffness and parafunctional loading values on the defined mechanical stimuli transfer from the implant to the surrounding bone.

Methods: A three-dimensional finite element model of two-piece threaded dental implant with internal hexagonal connection and mandibular bone block was constructed. Response surface method through face-centred central composite design was applied to examine the influence of two independent factors variables using three levels. The analysis model was fitted to a second-order polynomial equation to determine the response values.

Results: The results showed that the implant stiffness was more effective than the horizontal load value in increasing the stress and strain energy density transfers. The interaction between both factors was significant in decreasing the likelihood of bone resorption. Decreasing the implant stiffness and horizontal load value led to the increased stress transfer and unexpected decrease in the strain energy density, except at the minimum level of the horizontal load. The increase in the implant stiffness and horizontal load value (up to medium level) have increased the strain energy transfer to the bone.

Conclusions: The stress and strain energy density were transferred distinctively at the bone-implant interface. The role of both implant stiffness and parafunctional loading is important and should be highlighted in the preoperative treatment planning and design of dental implant.