Talk:Hydroxyapatite

Name

the international association of mineralogy strongly recommends the word hydroxylapatite rather than hydroxyapatite. I suggest this article is renamed to hydroxylapatite.

Bedrupsbaneman 16:32, 31 May 2005 (UTC)

Should Hydroxyapatite be listed as an alternate name? Is it an older spelling? RJFJR 18:42, 22 September 2005 (UTC)

I don't know about it being older but the alternate spelling is certainly in use in solid-state chemistry and quite a few of the medical articles I've read also call it Hydroxyapatite. If anyone can get a source for that recommendation then it's worth mentioning in the article IMHO --Edith The Hutt 16:10, 9 February 2006 (UTC)

I think that this is a case of two different sciences using two different names for the same thing. The medical profession seems to se hydroxyapatite. On the other hand the offical name of the mineral is Hydroxylapatite per the dictate of the International Mineralogical Association, the governing body of Mineralogy. Kevmin 04:06, 10 June 2007 (UTC)

I think it is pretentious to use an irregular spelling as the primary spelling for an article on a biomedical material, relying on an international association of mineralogy to set the standard. It is appropriate for them to control the usages of mineralogical names, such as whether a beryllium aluminum garnet should be called beryl, or one with a chromium color center should be called emerald while a similar green with an iron color center is not emerald, but it is not in their purview, with respect to mainstream chemistry to make up new names or spellings. Hydroxyapatite has been the proper spelling in chemical publications for longer than the mineralogy group has been in existence and it is acknowledged the preferred spelling in medical publications, and I would think that teeth had more to do with medical studies than with rocks.173.54.37.223 (talk) 18:44, 14 October 2010 (UTC)

As this article is primarily about the mineral, the accepted mineral name is appropriate. If you want, you could start a medical article or add to the bone mineral stub. Vsmith (talk) 20:32, 14 October 2010 (UTC)

I can't start a medical article, because I'm a mineralogist and not a medician. However, as the bones (teeth included) are largely comprising a mineral, this is the matter I am working with. The more, as my work adds and is very often related to the nomenclature and systematics of minerals - exclusively governed by the IMA and not IUPAC or any other commissions or associations - it is the IMA rules to be used for correct naming of minerals. Also, I will not provide Wikipedia with any more articles, for the reasons (fraud behaviour) explained in my page & talk page.Eudialytos (talk) 09:20, 29 May 2023 (UTC)

I agree with the anonymous editor 173.54.37.223, and I disagree with Vsmith. The article is not primarily about the mineral, in the sense of a substance found in rocks. In fact, I think the only place you find it in geology would be recent "fossils", which would more accurately be described as skeletal remains. In old deposits, which may come from bone originally, fluoride replaces much of the hydroxide, so it is no longer hydroxyapatite. So I think we should move the article to Hydroxyapatite. Eric Kvaalen (talk) 07:34, 29 July 2018 (UTC)

I have never encountered the use of the term with an ell in the middle in any chemistry textbook. Hydroxyapatite should be the name used consistently in the article. The lead should include the alternative name as aka Hydroxylapatite Petergans (talk) 08:42, 11 August 2018 (UTC)

Absolutely not.

"Hydroxyapatite" is WRONG. Again, point by point:

Bones are made of a MINERAL ---> the nomenclature proper for MINERALS (mineralogy) must be used --> IMA ([International Mineralogical Association] : List of Minerals (mineralogy-ima.org)) ---> the ONLY CORRECT name is H Y D R O X Y L A P A T I T E.

Using the name "hydroxyapatite" equals to lacking knowledge in mineralogy, and/or ignorance.Eudialytos (talk) 09:23, 29 May 2023 (UTC)

You do not seem to understand what is a mineral.

It doesn't matter if a mineral occurs in a bone, bladder stones, rocks, the Moon, or elsewhere.

There is ONLY ONE correct name for a mineral species. And this is/was set by the IMA - International Mineralogical Association, not IUPAC or any medical associations/commisions.

As such, EACH case of the COMPOUND we are talking about, which is, Ca5(PO4)3(OH) (ideally), is H Y D R O X Y L A P A T I T E.

Using the WRONG name "hydroxyapatite" is, simply, an ignorance.

Again, references:

[International Mineralogical Association] : List of Minerals (mineralogy-ima.org)

Hydroxylapatite: Mineral information, data and localities. (mindat.org)

Eudialytos (talk) 09:26, 29 May 2023 (UTC)

It doesn't matter if the name is given by a medical worker, mineralogist, or anyone else. We are talking about a SINGLE, THE SAME, mineral species. And its name is hydroxyLapatite, not "hydroxyapatite". If we talk about, say, a bacteria, we will always write Escherichia coli, right? Even though in, e.g., Polish it is pronounced differently, this is not a basis for writing it "Eszerichia koli".

Again, References:

[International Mineralogical Association] : List of Minerals (mineralogy-ima.org)

Hydroxylapatite: Mineral information, data and localities. (mindat.org)

Eudialytos (talk) 09:08, 29 May 2023 (UTC)

"Hydroxyapatite" is, simply, a WRONG name. At most, it can be treated as a synonym.

Refs.:

[International Mineralogical Association] (mineralogy-ima.org)

[International Mineralogical Association] : List of Minerals (mineralogy-ima.org)

Hydroxylapatite: Mineral information, data and localities. (mindat.org) Eudialytos (talk) 09:31, 29 May 2023 (UTC)

Tooth enamel use

The tooth enamel page says it's made of hydroxylapatite. Can someone add to this article why this substance isn't used for dental fillings? It would seem like a natural choice if the substance is identical. (I also asked this over at the dental fillings talk page, and that article would benefit from the answer to this question, if anyone knows.) Tempshill 06:30, 20 January 2006 (UTC)

IIRC it's about 90% hydroxylapatite yes, I'd speculate it's got something to do with the difficulty of forming it and that HAp in tooth enamel has a pretty distinctive microstructure which is very difficult to reproduce. That and maybe the fact you want to replace dentin too, I'm not a dentist or a bio-materials engineer so I couldn't really comment on that aspect. --Edith The Hutt 16:10, 9 February 2006 (UTC)

On usage of hydroxylapatite for small fillings: http://www.newscientist.com/article.ns?id=dn7058

--Md2perpe 14:07, 26 February 2006 (UTC)

Specific gravity imprecision

Hello,

The specific gravity is quoted as 3.08 in the text, but between 3.14 and 3.21 in the cartouche. Which one is right?

24.37.29.254 (talk) 20:25, 27 July 2011 (UTC)

Provided references give both, but it is more likely the larger value [1]. Lower one (3.08) might be due to porosity. Materialscientist (talk) 22:35, 27 July 2011 (UTC)

Requested move 29 July 2018

The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review. No further edits should be made to this section.

The result of the move request was: Consensus to move, therefore, moved. (closed by non-admin page mover) Dreamy Jazz ^{talk | contribs} 18:38, 12 August 2018 (UTC)

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Hydroxylapatite → Hydroxyapatite – See the comments under #Name arguing for the form without the "l" in the middle. Problem is, the Hydroxyapatite redirect has been modified a few times, so we cannot do a simple rename anymore. Eric Kvaalen (talk) 15:20, 29 July 2018 (UTC)--Relisting. Dekimasuよ! 16:44, 5 August 2018 (UTC)

• Support' this move 2601:541:4500:1760:95FF:79E9:370A:6174 (talk) 19:35, 5 August 2018 (UTC)
• Support The letter l in hydroxylapatite is completely wrong. Petergans (talk) 08:27, 11 August 2018 (UTC)
• Support The letter l in hydroxylapatite is completely wrong per above. --Smokefoot (talk) 00:24, 12 August 2018 (UTC)

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The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.

Equation for Byphasic Hydroxyapatite is Incomplete

The equation is given as

Ca_10−x(PO₄)_6−x(HPO₄)_x(OH)_2−x → (1−x) Ca₁₀(PO₄)₆(OH)₂ + 3x Ca₃(PO₄)₂

I attempted to add a simple equation for x as a function of Ca/P and its inverse. Using this equation, I got

$Ca/P={\frac {10-x}{6-x}}$

and

$x={\frac {6\cdot (Ca/P)-10}{(Ca/P)-1}}$

The equation for Ca/P from x is obvious from inspection, and the second equation, for x from Ca/P, is a simple inversion of the equation for x. But, the first line of this section says that Ca/P varies from 1.67 to 1.5 as x varies from 0 to 1, but the first equation has Ca/P varying from 1.67 to 1.8, so the formula for byphasic hdrolyapatite is incomplete -- the variable x in the formula actually has a scaling for each term that is not given. Since the valence of the calcium ion is +2 and the valence of the phosphate ion is -3, perhaps the formula should begin Ca_10-3x(PO₄)_6-2x...

If this is correct, the statement "(where x is between 0 and 1)" is incorrect. I could infer a correction from elementary inorganic chemistry but, to be sure that the scalings for the HPO₄ and OH ions are corre3ct, a knowledgeable correction from a mineralogist is invited here.

-- motorfingers : Talk 20:24, 15 September 2019 (UTC)