Question

The conversion of hydroxyapatite occurs due to presence of $F^-$ ions in water. The correct formula of hydroxyapatite is:

• A. $\left[3 Ca _{3}\left( PO _{4}\right)_{2} \cdot Ca ( OH )_{2}\right]$
• B. $\left[3 Ca ( OH )_{2} \cdot CaF _{2}\right]$
• C. $\left[ Ca _{3}\left( PO _{4}\right)_{2} \cdot CaF _{2}\right]$
• D. $\left[3 Ca _{3}\left( PO _{4}\right)_{2} \cdot CaF _{2}\right]$

Answer 1

Answer: (A)

The $F ^{\ominus}$ ions make the enamel on teeth much harder by converting hydroxyapatite, $\left[3\left( Ca _{3}\left( PO _{4}\right)_{2}\right] \cdot Ca ( OH )_{2}\right]$, the enamel on the surface of the teeth into much harder fluroappatite. $\left[3 Ca _{3}\left( PO _{4}\right)_{2} . CaF _{2}\right]$