1-Year pullout strength and degradation of ultrasound welded vs tapped craniomaxillofacial fixation screws

Autor: Alejandro López, Thayanithi Ayyachi, Tessa Brouwers, Jonas Åberg, Anna Finne Wistrand, Håkan Engqvist
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Polymer Testing, Vol 109, Iss , Pp 107519- (2022)
Druh dokumentu: article
ISSN: 0142-9418
DOI: 10.1016/j.polymertesting.2022.107519
Popis: A knowledge on the pullout forces of degradable craniomaxillofacial screws is essential in designing pediatric cranial implants. Herein, four non-identical commercially available screws composed of different aliphatic polyesters were fixated to 3D-printed poly(l-lactide) screw hole test rig and onto a bone substitute material using manual tapping and ultrasonic welding fixation techniques. A method for mechanical testing was developed to determine and compare their quasi-static pullout strength. The degradation of the screws was followed for up to one year in three different degrading environments. While the screw size influences the initial pullout force, the degrading environment, size, and screw composition determine the degradation rate which in turn influences the pullout force over time. Given the limited availability of standard methods, the method developed herein can be used in determining the pullout forces of degradable craniomaxillofacial screws and comparing the effectiveness of various screw insertion techniques.
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