Table 2.

CaP-based compounds, Ca/P ratio, and pKs values [66,67].

Compound	Ca/P Ratio	Application	Reference
Monocalcium phosphate monohydrate	0.5	Increase root fluoride uptake	[68]
Monocalcium phosphate anhydrous	0.5	Artificial bone graft	[69]
Dicalcium phosphate anhydrous	1	Polish agent for teeth Source of Ca and P in food supplements	[70]
Dicalcium phosphate dihydrate	1	Sustained release of highly water-soluble drugs	[71]
α-Tricalcium phosphate	1.5	Biodegradable composite for bone repair	[72]
β-Tricalcium phosphate	1.5	Orthopedic surgery	[73]
Calcium-deficient hydroxyapatite	1.5–1.6	Bone grafting	[74]
Hydroxyapatite	1.67	Repairing of hard tissues	[75]
Fluorapatite	1.67	Used as source of fluorine in pharmaceutical products	[76]
Tetracalcium phosphate	2	Applied as cements and coatings on metallic implants	[77]