Surface Modification of Zirconia Substrate by Calcium Phosphate Particles Using Sol-Gel Method

摘要

Surface modification with a biphasic composition of hydroxyapatite (HA) and tricalcium phosphate (TCP) was performed on a zirconia substrate using a sol-gel method. An initial calcium phosphate sot was prepared by mixing a solution of Ca(NO3)(2)center dot 4H(2)O and (C2H5O)(3)P(O), while both porous and dense zirconia were used as substrates. The sol-gel coating was performed using a spin coater. The coated porous zirconia substrate was re-sintered at 1350 degrees C 2 h, while coated dense zirconia substrate was heat-treated at 750 degrees C 1 h. The microstructure of the resultant HATTCP coatings was found to be dependent on the type of zirconia substrate used. With porous zirconia as a starting substrate, numerous isolated calcium phosphate particles (TCP and HA) were uniformly dispersed on the surface, and the particle size and covered area were dependent on the viscosity of the calcium phosphate sol. Conversely, when dense zirconia was used as a starting substrate, a thick film of nano-sized HA particles was obtained after heat treatment, however, substantial agglomeration and cracking was also observed.