Deposition of Biocompatible Polymers by 3D Printing (FDM) on Titanium Alloy.

Dominika Grygier,Maciej Kujawa,Piotr Kowalewski

doi:10.3390/polym14020235

Dominika Grygier, Maciej Kujawa + Show 1 more

Open Access

https://doi.org/10.3390/polym14020235

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Abstract

Nowadays, the replacement of a hip joint is a standard surgical procedure. However, researchers have continuingly been trying to upgrade endoprostheses and make them more similar to natural joints. The use of 3D printing could be helpful in such cases, since 3D-printed elements could mimic the natural lubrication mechanism of the meniscus. In this paper, we propose a method to deposit plastics directly on titanium alloy using 3D printing (FDM). This procedure allows one to obtain endoprostheses that are more similar to natural joints, easier to manufacture and have fewer components. During the research, biocompatible polymers suitable for 3D FDM printing were used, namely polylactide (PLA) and polyamide (PA). The research included tensile and shear tests of metal–polymer bonds, friction coefficient measurements and microscopic observations. The friction coefficient measurements revealed that only PA was promising for endoprostheses (the friction coefficient for PLA was too high). The strength tests and microscopic observations showed that PLA and PA deposition by 3D FDM printing directly on Ti6Al4V titanium alloy is possible; however, the achieved bonding strength and repeatability of the process were unsatisfactory. Nevertheless, the benefits arising from application of this method mean that it is worthwhile to continue working on this issue.

Highlights

The replacement of a hip joint after osteoarthritis or fracture is nowadays a standard surgical procedure performed worldwide [1]
Researchers focus on creating endoprostheses that are structurally similar to the natural joint [6]
The use of “soft” sliding materials results in lower friction resistance and higher durability than with classic “hard” materials used in endoprostheses

Summary

Introduction

The replacement of a hip joint after osteoarthritis or fracture is nowadays a standard surgical procedure performed worldwide [1]. Researchers focus on creating endoprostheses that are structurally similar to the natural joint [6]. Sonntag et al distinguished four approaches to the development of new endoprostheses [7]: (a) (b) (c) (d). The introduction of new materials; The application of a coating; The modifcation of the surface layer; The use of “soft” sliding materials. The usage of “soft” sliding materials is the closest to a natural joint, where there is a soft tissue covering. The use of “soft” sliding materials results in lower friction resistance and higher durability than with classic “hard” materials used in endoprostheses

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