The composition is comprised of a buffering agent having a pH buffering action in the oral cavity and a calcium preparation. The buffering agent is a phosphorylated oligosaccharide in the form of a sodium salt or a calcium salt. The concentrations of the buffering agent and the calcium preparation are selected to provide a Ca/P ratio in the saliva after mastication that is substantially 1.0 to 1.67. The phosphorylated oligosaccharide of the phosphorylated oligosaccharide in the form of a sodium salt or a calcium salt is a glucan consisting of 3 to 5 glucoses with α-1,4 linkages, one phosphate group being linked to the glucan, or glucan consisting of 2 to 8 glucoses with α-1,4 linkages, two phosphate groups being linked to the glucan. The calcium preparation is selected from the group consisting of calcium carbonate, calcium chloride, calcium lactate, calcium gluconate, whey calcium, organic acid calcium, colloidal calcium carbonate, casein phosphopeptide calcium and calcium fluoride.