Thesis about artificial bone

   I major in engineering sciences in college. Today, I read a thesis about artificial bone, which I was interested in. It was very difficult for me, but I have finished reading it! So, I wrote a summary of the thesis.

Summery
   Our body is supported by the bones from head to foot. But if once a bone is broken or does not engage smoothly ,because of a traffic accident or illness or aging, it will be difficult for us to live a daily life. So, we need “artificial bone” to make up for the fracture. And we also need “metallic material”, which display a small coefficient of friction and fuse itself with bones directly.
   For example, titanium and titanium alloys are capable metals. They don’t react easily on a water solution because their surfaces are covered by titanium oxide (TiO2). But titanium oxide reacts on sodium hydroxide (NaOH), and form hydration gel of sodium titanate. This hydration gel change into the amorphous layer of sodium titanate, which displays the high strength to the loading, with heated at 600℃ for 1 hour. The amorphous layer of this metal elutes sodium ions and draw oxonium ions in the body, and forms a lot of Ti-OH groups on its surface. These groups are combined to calcium ions and phosphate ions, and they form “apatite”, which is the crystal of hexagonal system. The layer of apatite fuse itself with the surrounding bones, and then work as an artificial bone. 

   The metallic materials,which display the high strength to the loading and fuse themselves into bones automatically like sodium titanate, are called “bioactive metal”. These bioactive metals expected to use as the artificial bones which locate in high loaded place in the body, like human knee, elbow, hip joint, wrist and other joints, or the root of a tooth. They will be a help for a lot of people, who suffer from physical injuries, to live a healthy and cultural life.




I will find a new and high-performance metallic material in the future!!

Reference
化成処理,高温処理/人工骨,人工関節
小久保正,金鉉敏(2000)