Design and development of hydroxyapatite/zirconia (HA/ZrO2) scaffold for guided bone regeneration

Abstract

Highly porous scaffold made of bioceramics such as hydroxyapatite (HA) have been widely investigated for guided bone regeneration, however their inferior mechanical strength limits their clinical use to non load bearing applications. In this study we have synthesised HA/ zirconia (ZrO2) mixtures (5, 10, and 20 wt%) using microwave assisted wet precipitation method. Phase composition and particle morphology of the mixture was studied using X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) respectively. Presence of ZrO2 in mixtures was confirmed by the presence of peak at 30.22° in XRD, which increased in intensity as concentration of ZrO2 increased in the mixture. Porous structures were generated by using polymeric sponge burn off method. Solid loading of sponge was optimised to achieve good degree of porosity, pore size and pore interconnectivity. SEM analysis of scaffolds revealed good pore interconnectivity and pore size greater than 200 microns. Scaffolds were dipped in solution of poly-L-lactic acid and HA/ZrO2 prior to the compressive strength measurements. The compressive strength of scaffold increased from 1.73 to 2.47 MPa when ZrO2 content increased from 5% to 20% for 20 wt% solid loading. For 30 wt% solid loading, compressive strength increased from 1.83 to 2.63 MPa as concentration of ZrO2 increased.