Preparation and Deposition of Hydroxyapatite on Biomaterials by Sol-Gel Technique-A Review

Abstract

Hydroxyapatite Ca 10 (PO 4) 6 (OH) 2 (HAP) is an important inorganic biomaterial which has attracted the attention of researchers in recent years. Due to its chemical and structural similarity with the mineral phase of bone and teeth, it is widely used for hard tissues repair. Amongst various methods, sol-gel technique has achieved more popularity recently due to synthesis of ceramics powders. The sol-gel process is easily applicable to surface coating as it allows the preparation of high-quality HA thin films on metal substrates. It has been observed from the studies that the protective atmosphere during sintering process accomplished after sol-gel coating produces good uniformity of coating material which significantly leads to a reduction in the porosity of the coating film. In another study it was revealed that mechanical properties of commercial HAP can be significantly improved by adding P 2 O 5 and Na 2 CO 3 without altering its biocompatibility. It has been found from the extensive literature review that homogeneous and crack-free coatings were obtained on biocompatible substrate implant at higher sintering temperatures. The particle size of the HAP powder increases with the increase of the sintering time and sintering temperature. In this paper a review of the studies done for the preparation and deposition of HAP powder with the solgel technique has been detailed.

Biodegradable/biocompatible coated metal implants for orthopedic applications

“…Sol-gel technique has attracted much attention to the researchers due to its well-known inherent advantages in generating ceramic powders [55]. Sol-gel approach is the process of introducing coated surface into implant at a relatively low temperature that tolerates the deposition of calcium phosphate materials during the formation of coated layer.…”