In Vitro Gradual Decrease in Strength of Ti Scaffolds in Hank’s Solution upon Long-Term Immersion: Challenges and Prospective Solutions

Abstract

Although Ti scaffolds offer great potential in orthopedic applications, their porous nature raises new questions, such as low relative density and high surface area. This work investigated the gradual decrease in the strength of Ti scaffolds during long-term immersion in Hank’s solution. After 180-day immersion, the samples have a 23.3% and 26.6% reduction in yield strength and a 9.0% and 11.2% reduction in compressive strength in dynamic and static solutions, indicating potential failure during the long-term service. A large exposure area to the solution leads to a high corrosion rate, which results in the consumption of the scaffolds and, consequently, decreased strength. Although the covered deposits on the scaffolds reduce the ion release to some extent, the scaffolds still have a slowly ongoing decrease in strength. Based on the durability considerations, some methods, such as decreasing porosity and surface treatments, are proposed to alleviate this phenomenon of Ti scaffolds.