Bioceramics are ceramic materials specially developed for use as medical and dental implants.
They are usually used to replace hard tissue in the body like bone and teeth. Common bioceramics
are alumina, zirconia and a form of calcium phosphate known as hydroxyapatite.
Bioactive and bioinert:
Bioactive ceramics interact with the body so that tissue bonding and eventual incorporation into
the body occurs after a time. Calcium phosphate-based bioceramics are bioactive.
Bioinert ceramics do not interact with the body environment apart from causing an initial ‘fibrous tissue’
reaction, which coats the ceramic. Alumina and zirconia-based ceramics are classed as bioinert.
Alumina (Al2O3) is a white powder. When shaped, compressed and heated to a high temperature (sintering),
the ceramic that results has high density, high strength, excellent corrosion resistance, good
biocompatibility and high wear resistance. It can be machined, ground and polished to a high-quality product.
Zirconia (ZrO2) is also a white powder. It can be compressed and sintered into a very strong ceramic.
By adding yttrium oxide and small amounts of magnesium oxide, a better-wearing bioceramic called
Y-TZP can be made.
Calcium phosphate or hydroxyapatite – Ca10(PO46(OH)2 – is the principal component of natural bone in the body.
Ceramics made from synthetic calcium phosphate can also be used in medical applications. The problem is that
these ceramics are not as strong as alumina or zirconia ceramics.
Bioceramic bones and teeth:
Alumina bioceramics are used as replacement parts in hip and knee operations. The inertness of the ceramic,
its high wear resistance and its excellent biocompatibility make it the ceramic of choice.
The high load-bearing properties of alumina also makes it an ideal ceramic for dental implants.
Calcium phosphate ceramics can bond to bone and promote bone growth at their surfaces. A popular use of
these ceramics is as coatings on dental and orthopaedic implants. For example, titanium tooth root pegs
coated with hydroxyapatite (a form of calcium phosphate) give a longer lasting implant than pegs that
have been glued or cemented in place. The hydroxyapatite binds chemically with living bone because
it is a bioactive ceramic.
Often as a result of injuries sustained in road crash accidents, bone reconstruction operations are needed.
Material is heated to 1,000°C. After this heating process, what remains is an open 3D mineral shell of
Small cubes of this material can be grafted into the damaged living bone site. Over a period of time,
new bone develops and grows in and around the implant. Successful repair of the damaged bone is achieved.
Wishing you all the best,