Hydroxyapatite Deposition on Silicon Nitride and SiAlON Ceramic Substrates via Biomimetic Method

Authors : Şeniz Reyhan Kuşhan Akin

Pages : 146-151

View : 37 | Download : 82

Publication Date : 2023-11-01

Article Type : Research

Abstract :Silicon Nitride (Si3N4) ceramics hold significant promise as materials for biomedical implants, but their biocompatibility and osseointegration performance can still be improved to improve host tissue-implant interaction. One approach to improve interaction involves the application of a Hydroxyapatite (HAp) Ca10(PO4)(OH)2 coating. Various techniques, including solid-state reactions, hydrothermal methods, sol gel processes, and biomimetic approaches, have been employed for this purpose, achieving partial success in mimicking bone-like apatite formation. Biomimetic coating, among these methods, is particularly valuable for enhancing the biocompatibility of different orthopedic implants. It can be applied not only to ceramics but also to materials featuring active chemical groups on their surfaces, such as metals and organic polymers, which serve as nucleation sites for mineralization. In this study, Si3N4 and SiAlON ceramics were compared regarding their potential to deposit hydroxyapatite in simulated body fluid (SBF) with varying concentrations. The apatite layers formed on the surfaces after immersion in 1.5 SBF were analyzed using a Scanning Electron Microscope (SEM) and energy-dispersive X-ray (EDX) analysis. Consequently, Ca/P ratios matching nonstoichiometric biological apatite values were observed on surfaces exposed to 1.5 SBF. Microstructure studies revealed the widespread formation of a typical HAp structure in Si3N4 samples, whereas it was less prevalent in SiAlON samples. This behavior is discussed, particularly considering the grain boundary phase\'s influence on HAp formation tendency.
Keywords : Silicon Nitride, SiAlON, Biomimetic Coating