Gums that contain calcium phosphate compounds, e.g., amorphous calcium phosphate (ACP), have been shown to have anticaries properties in in situ models. Objectives: To investigate (1) effects of chewing gums containing different amounts of separate Ca and PO₄ sources on salivary Ca and PO₄ levels compared to an ACP containing gum, and (2) effects of using basic or acidic PO₄ source on salivary pH, Ca and PO₄.  Materials: The ACP containing gum Tridentä was used as control. Eight experimental gums were prepared by adding Ca lactate (5 or 1.3 mass%) and Na₂HPO₄ or NaH₂PO₄ (2 or 0.5 mass%) in Extra^TM.  Methods: 1-min saliva samples were collected from 5 subjects after 2 and 15-min gum chewing.  Each sample was divided into three aliquots. #1 was directly acidified (total) and #2 was centrifuged and then acidified (cent) to release Ca and PO₄, which were analyzed spectrophotometrically. Aliquot #3 was used to measure pH under 5% CO₂.  Results:  All differences noted were significant at p<0.05, ANOVA.  The 2 and 15-min pH's for all the gums were not significantly different. The 2-min total Ca's (18±7.3 to 27.2±15.2 mM) from 4 gums with the 5% Ca content were significantly greater than those for the Trident^TM (3.8±1.0 mM).  Gums contained 5% Ca and 0.5% PO₄ produced a higher 2-min cent Ca (18.2±7.9 and 16.4±7.7 mM) than the Tridentä (2.1±0.5 mM). Gums containing 2% PO₄ and 5% Ca additives produced a higher 2-min total PO₄ (14.0±6.8 and 18.3±1.4 mM) than the Tridentä (5.9±1.0 mM).  Although some differences were noted in the 15-min samples, they appeared to be unrelated to the Ca and PO₄ contents in the gums.  Conclusions: Gums containing separate Ca and PO₄ sources can provide higher 2-min salivary Ca and PO₄ than a gum containing ACP. Supported by NIDCR grant DE05354, ADAF, and NIST.