Crystallography of Dental Calculus and the Precipitation of Certain Calcium Phosphates

Abstract

Samples (52) of dental calculus were examined by X-ray crystallography.. Apatite was found in all samples. The otherwise rare whitlockite was found in 41 of 52 samples, a higher frequency than in salivary gland calculi. This substantiates the authors'' hypothesis of an anti-apatite factor in saliva. Brushite was found in 7 samples of 21 in calculus from mandibular anterior teeth, but not from other regions. This seems to follow from the different saturation conditions, for in mandibular saliva from 19 students supersaturation with brushite was found in all samples but 3, in parotid saliva unsaturation with brushite in all samples but one. Five calculus samples contained calcium oxalate mono-hydrate, 3 samples an unidentifiable compound. Corrosion products from amalgam fillings were found in two samples. It is concluded that Ag3Sn corrodes faster than other constituents of set amalgam.