Sodium polyphosphates are often added to pet foods to help slow the mineralisation of dental plaque. When released into the oral cavity, they bind calcium ion in saliva and directly limit the formation of tartar.
Sodium polyphosphate salts are used in many human toothpastes to improve oral hygiene. In animals, polyphosphates must be incorporated into the kibble where they are released during chewing.
The calcium ions in saliva are liable to form calcium hydroxyapatite crystals, which are the mineral matrix of tartar. Sodium phosphates have the capacity to chelate the calcium, significantly reducing tartar deposits on the teeth. The calcium phosphate complexes disassociate during digestion and the calcium and the phosphorus are released into the digestive tract where they are absorbed in accordance with the needs of the animal.
Sodium phosphates are a family of mineral salts comprising more than 150 different substances (orthophosphate, pyrophosphate, polyphosphate, metaphosphate).