Osseointegration of Titanium and Steel Additive Manufactured Implant in Rabbit Tibia under External Fixation: Comparative Study

Abstract

<jats:p><jats:bold>Relevance</jats:bold>. The main goals of successful prosthesis remain ensuring the osseointegration and infectious safety of implants.</jats:p><jats:p><jats:bold>The purpose of the study</jats:bold> — the comparative analysis of osseointegration of titanium and steel additive manufactured implants in the rabbit tibia under additional fixation by Ilizarov apparatus.</jats:p><jats:p><jats:bold>Materials and Methods</jats:bold>. The study was performed on 20 chinchilla male rabbits. The animals of the first group (n = 8 ) were implanted a stainless steel product EOS PH1 (EOS, Germany), the animals of the second group (n = 12) — a titanium alloy Ti6Al4V product. The implant was additionally fixed by Ilizarov apparatus. The implants were processed with additive technology by selective laser fusion at the EOSINT M 280 installation (EOS, Germany). The survival and safety of the implants were assessed using clinical, histological, laboratory and statistical methods.</jats:p><jats:p><jats:bold>Results</jats:bold>. The implant fall due to chronic inflammation was found in 2 animals of group 1 and none in group 2. The formation of weakly mineralized bone tissue on the surface of the implant was noted in 3 weeks in all cases. The bone became more mineralized by the 12<jats:sup>th</jats:sup> week of the experiment. However, in group 2, the calcium content and Ca / P ratio of the newly formed bone tissue at the 3<jats:sup>rd</jats:sup> and 12<jats:sup>th</jats:sup> week after implantation were significantly higher than in the animals of group 1. This indicated the greater maturity of the bone tissue in animals of group 2 at all stages of the experiment. In group 1, the compact plate osteoporosis and calcium-phosphorus balance disturbance were greater.</jats:p><jats:p><jats:bold>Conclusion</jats:bold>. The results of the study indicate that the survival rate (osseointegration) and safety of the product made of the titanium alloy were higher compared with the stainless steel product.</jats:p>

Design and Structural Factors’ Influence on the Fatigue Life of Steel Products with Additive Manufacturing

“…Surface roughness is believed to promote the osseointegration of implants [10]. In our case, we found a relatively low level of surface roughness regarding the studied steel AM implant (Table 4).…”

“…Thus, the EBM method requires more machining and, therefore, a margin regarding the size of the original model used for the final additive manufactured (AM) product. However, in medicine, the roughness of a product's surface is useful for the osseointegration process [10,11]. In addition, osseointegration is positively impacted by the internal porosity of AM products, which is usually viewed as undesirable for AM metal products in other industries due to a decrease in mechanical properties [11].…”