Abstract: A dental composition which comprises (A) a phosphoric acid group-containing monomer, (B) a carboxylic acid groups-containing monomer and (C) water as main components in amounts of 0.5 to 50% by weight, 1 to 50% by weight and 5 to 90% by weight, based on the composition, respectively; and a dental adhesive kit comprising a dental primer composition containing the monomer (A) and water and an adhesive containing a carboxylic acid-containing polyfunctional monomer and a polymerizable initiator.

Abstract: A dental composition containing an acid such as maleic acid, phosphoric acid or citric acid; an organosulfonate and/or an organosulfinate such as an acid group-containing (meth)acrylate monomer having in the molecules thereof a carboxyl group or a phosphoric acid group, a sodium benzenesulfonate or a sodium p-toluenesulfinate; a water-soluble organic solvent such as ethanol or propanol; and the water: but without substantially containing any polymerizable monomer except the above acid group-containing (meth)acrylate monomer, or further containing a hydroxy- or a dihydroxyalkyl (meth)acrylate monomer. For adhesion of a dental filling material to teeth, the composition of the invention is used as a pre-treatment agent on teeth prior to applying an adhesive. This makes it possible to treat enamel and dentin simultaneously and to accomplish strong adhesive strength to both of them.