Synthesis and Characterization of Eggshell-derived Hydroxyapatite for Dental Implant Applications

¹ Department of Materials and Metallurgical Engineering, University of Ilorin, Ilorin, Nigeria
² Department of Mechanical Engineering, Nile University of Nigeria, Abuja, Nigeria
³ Department of Mechanical Engineering, Landmark University, Omu-Aran, Nigeria
⁴ Department of Mechanical Engineering Science, University of Johannesburg, Johannesburg, South Africa
⁵ Gallogly College of Engineering, University of Oklahoma, Oklahoma, United States
⁶ Mechanical and Construction Engineering Department, Northumbria University, Newcastle, United Kingdom

^* Corresponding author: omoniyi.po@unilorin.edu.ng

Abstract

Hydroxyapatite (HAp) production from eggshells for dental implant purposes involved a novel approach utilizing a wet chemical precipitation technique. The eggshells, finely ground to a size below 250 µm, underwent calcination at a high temperature of 900°C for 2 hours. This thermal treatment facilitated the conversion of calcium carbonate into calcium oxide (CaO) while eliminating any organic components in the eggshell. To initiate the synthesis of HAp, a solution comprising 0.6 M phosphoric acid was added to the CaO dispersed in water. The resulting mixture was allowed to undergo aging at different time intervals ranging from 0 to 24 hours, promoting the formation of HAp. Subsequently, the HAp particles were oven-dried at 100°C for 2 hours to remove residual moisture. Finally, the dried particles were sintered at 1200°C in a muffle furnace to achieve the desired properties for dental implant applications. XRD peaks at 25, 33, 40, and 50° confirm the synthesized material as HAp. Vibrational modes of phosphate (PO₄^3-), hydroxyl (OH^-), and carbonate (CO₃^2-) groups indicate carbonated HAp. Synthesized HAp holds potential for biomedical applications.