Hi,

I'm afraid I don't completely understand your question, but a range of materials are used as implant materials, from degradable (bio-resorbable) polymers (PLA/PGA) to unresorbable polymers (PMMA), ceramics (HA), glasses (45S5 bioactive glass), metals (Ti, Au, SS, Co-Cr etc..). It is easy to classify materials broadly as bio-inert (such as gold, zirconia) and bio-active (HA, 45S5). Some are used as bulk materials, others as coatings on bulk materials, and yet others are scaffolds for tissue engineering applications.. What you probably mean by "biologically human" is those materials that don't get an adverse response from the body. Realistically speaking, it's one issue for the body to recognise something as "human or non-human", and another issue when the body has to deal with degradation products. Even if the material surface is bio-inert, the degradation products can generate a wide range of responses, from chronic inflammation to fibrous encapsulation depending on the chemical and physical properties of the bulk, as well as the surface characteristics of the newly formed degradation products. Therefore "biologically human" may not be a really textbook thing to aim for.. Biology is complicated =)

If you could elaborate your question, I may be able to provide a more detailed answer..

Best regards

Hi， I think the hydroxyapatite is the most important biomaterial in medicine。

Agree with Furqan - please rephrase your question to more specific. Such general formulation is difficult to answer.... It would be wise to consult internet sources first...

The most common materials used in orthopaedic implants are metals and polyethylene. But advances of marine biotechnology look into mullusks proteins.

www2.uakron.edu/cpspe/Columbus_Dispatch_Heinz_1-30-2011.pdf

https://www.osc.edu/files/press/releases/2011/.../hendrik_heinz.pdf

Thanks a lot to all support idea n information

I think that Dr Razak means which is the most biocompatible material can be used as dental or hip implant. If this is the question, I think that titanium and titanium alloy is the material of choice for these purposes. However, there are many attempts to use zirconia or titanium and zirconia alloy for dental implant. Hydroxyapatite and bioactive glasses can not be used as a bulk material for fabrication of dental implant, but can be used as coatings to improve bone-bonding ability of titanium dental implant in certain circumstances.

Some comment to the above answer. Indeed, if there are load-bearing implants, metals (Ti) are common choice, although in spinal instrumentation also polymers (PEEK) are being used. For dental (as far as I know) zirconia is used for abutments and restorations only, not for the screws. Many people mixing "zirconia" (ZrO2) and "zirconium" (metal), so "zirconia alloy" does not exist. Zirconium alloys (on the contrary to Ti) do not support osteo/osseointegration; they are used mainly for fixations to be removed later.

HAP is mostly used for coatings, and BAG for cavity fillings (BonAliveTM or the like), but there are also glass-fiber reinforced BAG composites which are very promising bone substitutes.

Thank you Micheal for your nice comments. Zirconium and titanium alloy has been used to fabricate dental implant which id used in the clinic nowadays.

Why zirconium alloy does not support or enhance osseointegration?

Because Ti oxid layer is biocompatible, although there are attempts to modify zirconia surface with hydroxyapatite. However, ask the manufacturer: do you want the zirconium dental implant ... Even if you hear: yes; you do not do this until you compare the stress intensity factor K1c with metals ;-][