The crystalline components of dental calculus in the domestic cat

Feline dental calculus was found to consist of carbonate-containing hydroxyapatite, Ca10(PO4)3(CO3)3(OH)2. Other forms of calcium phosphates consistently present in human calculus, and calcium carbonates found in horse, dog, and miniature pig calculus were not present. Calculus composition was performed using wet chemical method, x-ray diffraction, spectrographic analysis, and infrared spectrophotometric analysis. All samples showed traces of amorphous material, including magnesium and ammonium, but were negative for uric acid, cysteine, and oxalate.