Previous studies suggest that gums containing separate calcium/phosphate compounds produce greater increases in salivary, plaque, and plaque fluid calcium and phosphate (Ca/PO4) concentrations than moderately soluble single salts (i.e. α-TCP) previously tested as anti-caries gum additives. Objectives: Compare the effects of single- and multi-salt chewing gums on these concentrations after a sucrose challenge. Methods: Baseline saliva and plaque specimens were collected from 14 subjects before a sucrose solution rinse. Subjects then chewed Ca/PO4 containing test gums (with 0.45 mmole Ca and 0.33 mmole PO4). (Gums: 1 = Ca/PO4 free control, 2 = Ca(C3H5O3)2·5H2O and NaH2PO4, 3 = Ca3(C6H5O7)2 and encapsulated Na2/K2HPO4, and 4 = commercial gum containing the single salt complex CPP-ACP. Post rinse samples collected at 2 times: saliva samples from 3-4 and 8-9 min.; plaque samples from 5 and 10 min. (timing suspended during plaque collection). Whole saliva, centrifuged saliva, plaque, and plaque fluid were analyzed for total Ca/PO4 concentrations by spectrophotometer. Centrifuged saliva and plaque fluid were analyzed for free Ca and pH by microelectrode. The data, computed as change from baseline, was examined by ANOVA or ANOVA on ranks. Results: Results where statistical differences were found (Rankings significant at p<0.05; an “=” indicates no statistical difference, but gums are shown in order of magnitude of measured values):
Time | Centrifuged Saliva | Whole Saliva | Plaque Fluid | |||
Free Ca | Total Ca | Total PO4 | Total Ca | Total PO4 | Free Ca | |
1 | 2>4=1>3 | 2=3>4=1 | 3<2=4=1 | 3=2>1; 3>4; 2=4; 4=1 | 3>2,4=1; 2>1 | 2>4=1=3 |
2 | 2=4=1>3 | 3=2>4=1 | 3=2=1=4 | 3=2>4=1 | 3>2=4=1 | 2>3,1; 2=4; 4=3=1 |
Conclusions: These increases suggest a greater cariostatic effect for separate-salt gums compared to the single-salt and Ca/PO4 free gum. For many parameters the single-salt gum was not different than the Ca/PO4 free gum.