Oral Ca/PO4 After Chewing Multiple-Salt Gums Following Sucrose Rinse

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.