Enhanced osseointegration of Ti6Al4V ELI screws built-up by electron beam additive manufacturing: An experimental study in rabbits
Abstract
In the present study, the osseointegration of additively manufactured screws with a micro-rough surface structure and conventionally machined Ti6Al4V ELI screws with a smooth surface structure is compared. Screws were implanted in rabbit femurs or tibiae for two weeks. The additively manufactured screws exhibited a micro-rough surface with attached semi-molten powder with a size of 50-100 μm and blunt threads, whereas the conventionally machined screws showed a smooth surface and sharp threads. The bonding strength of the additively manufactured screws was significantly higher than that of the conventionally machined screws. The additively manufactured screws showed higher bone-to-implant contact than the conventionally machined screws. Considerable amount of bone tissue on the surface of the additively manufactured screws remained after the push-out tests, and the rabbit tibiae with the additively manufactured screws were significantly damaged, indicating a higher osseointegration rate. Active osteogenesis was observed around the semi-molten powder of the additively manufactured screws, and new bone was well developed along the micro-rough surface. Overall, this study shows that the micro-rough surface improved the bone ingrowth and suggests that additively manufactured screws may be an alternative to conventionally machined screws.
- Publication:
-
Applied Surface Science
- Pub Date:
- April 2020
- DOI:
- 10.1016/j.apsusc.2019.145160
- Bibcode:
- 2020ApSS..50845160L
- Keywords:
-
- Additive manufacturing;
- Ti6Al4V ELI;
- Surface roughness;
- Osseointegration;
- Bone-to-implant contact