Formation of Calcium Phosphates in Saliva and Dental Plaque

This is an X-ray diffraction study of the mineral phases in saliva and early dental plaque. The salivas studied came from pa-tients with cystic fibrosis (CF), those with asthma, and heavy and light calculus formers. One-week old plaque was studied from in-dividuals who are heavy, moderate, and light calculus formers. The submandibular saliva of children with cystic fibrosis (CF) has been shown to be turbid when compared to saliva from chil-dren without CF.1 In addition, calcium, plhosplhorus, and protein levels in saliva sam-ples from children with CF have been found to be higher than normal.1-3 It has been suggested that the combination of high cal-cium and high protein levels results in a precipitate that gives rise to the charac-teristic pathological and clinical findings of CF, that is, obstruction of the tracheo-bronchial tract and other mucous-secreting passageways.1.4 It has been shown that this precipitate, mainly a calcium-phosphopro-tein,5 is soluble in ethylenediaminetetraacetic acid in vitro and can be reprecipitated by adding calcium.1 When CaCl2 is added to normal submaxillary saliva, a precipitate identical to that found in saliva from people with CF forms and the electrophoretic pat-tern of the precipitate is similar to that found in saliva from people with CF.1 This finding indicates that the binding of calcium to protein rather than mineral formation i