There is hydroxyappatite granules and the paste (cement). The 2 are different. I think but am not exactly sure that the paste is used to FILL in dents to the bone. It is a good material to fill in a dent or dingie, kind of like plaster to fill in a hole in the wall. Orthopedic surgeons use it for bone fill as do max faxes. But has LIMITATIONS when used to BUILD UP a SHAPE.
Plastic surgeons, such as Mendelson, use the GRANULES which are said to be porous and are mixed with the patients blood and additional collagen (powder) which is said to assist in tailoring a SHAPE to it. HOWEVER, it is used for small volume augmentation. So, it's use would be best for someone where an off the shelf implant would be too BIG for someone needing a small augmentation. But not good if a more significant augmentation was needed.
As to the MATERIAL; hydroxyappetite, it's a calcium phosphate compound like bone and an INORGANIC material LIKE bone. (Minerals are inorganic materials even though your bones are made from them.). With regard to the GRANULES, Coral from the ocean is the DEAD skeletans of the coral sessile animals which is mostly lime (cacium carbonate). The porous ocean coral used for the HA granules is formed by a hydrothermal exchange reaction where the calcium carbonate coral is converted to hydroxyappetite such that the porousity remains. With regard to the PASTE or 'cement' used to fill bone dents (and sometimes by max faxs to augment), the HA is higher density--not so porous--. It's usually found in some rocks. But can be synthesized.
What I'm trying to convey here is that to the best of my knowledge, the HA used either for the bone paste to fill in dents or the granules used is NOT obtained from COWS. However, the collagen powder used WITH the granules (in facial augmentation as some PS's like to use it) might come from cows (or some other mammal). Collagen, along with the patient's BLOOD is mixed with the granules to make it more MOLDABLE to get a SHAPE with it.
So, for face augmenting, providing it's only a SMALL augmentation where an implant could be too BIG, you'd want to have what the PS's use which are the HA GRANULES and not the paste stuff the orthos use to fill bone dents or some max fax docs use to augment with.
Personally, and this is probably JUST ME (given the arthritis in almost every joint), I would NOT use it HA. Because the stuff can crystallize into NEEDLE SHAPES and lodge in the joints. Even people who have not had any of this stuff implanted in them can get Hydroxyapatite crystal deposition disease (arthritis everywhere). PERHAPS it is this type of crystallization or re-Xtalization that MIGHT occur which would explain tissue IRRITATION.
Here is article by a PS who uses the GRANULES for modest augmentation.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2906722/
