Rod-shaped apatite crystals for use e.g. in remineralization of teeth or bones or in toothpastes have improved length:breadth ratio and variable hydroxide:fluoride ion ratio

摘要

Rod-shaped apatite crystals are such that the length:breadth ratio is -5; and the hydroxide and fluoride ions can be exchanged. Rod-shaped apatite crystals of formula Ca5(PO4)3(OH)x(F)y are such that: (i) the length:breadth ratio is -5; and (ii) x + y = 1 such that when x or y is not zero the crystals exist as single hydroxide and fluoride apatite crystals and/or a mixture of mixed crystals and (1-x). 100% of the hydroxide ions can be replaced by fluoride ions when y = zero.