PROBLEM TO BE SOLVED: To provide a dental composition having high adhesiveness even to a tooth substance having a carious portion. A phosphoric acid group-containing monomer (A-1) represented by the following general formula (1), a phosphoric acid group-containing monomer (A-2) represented by the following general formula (2), and water ( B) and a hydrophilic monomer (C) having no acidic group as an optional component, and the mass ratio of the monomer (C) and water (B) ([of the monomer (C) The content]/[content of water (B)]) is less than 1. (In the general formula (1), R 1 represents a hydrogen atom or a methyl group, and m represents an integer of 6 to 12.) (In the general formula (2), R 2 represents a hydrogen atom or a methyl group, and n represents an integer of 3 to 5.) [Selection diagram] None【課題】齲蝕部分が存在する歯質に対しても高い接着性を示す歯科用組成物の提供。【解決手段】下記一般式（１）で示されるリン酸基含有単量体（Ａ－１）、下記一般式（２）で示されるリン酸基含有単量体（Ａ－２）、水（Ｂ）、および、任意成分として酸性基を有しない親水性の単量体（Ｃ）を含み、当該単量体（Ｃ）と水（Ｂ）との質量比率（［単量体（Ｃ）の含有量］／［水（Ｂ）の含有量］）が１未満である、歯科用組成物。（一般式（１）中、Ｒ1は水素原子またはメチル基を表し、ｍは６～１２の整数を表す。）（一般式（２）中、Ｒ2は水素原子またはメチル基を表し、ｎは３～５の整数を表す。）【選択図】なし
