TECHNICAL FIELD The present invention relates to a dental composition comprising a polymerization initiator system containing a tertiary phosphine compound, for producing a photo-hardened dental composition, and a method of using the aromatic tertiary phosphine compound.Specifically, the present invention is a dental composition, (A) one or more compounds having at least one polymerizable double bond, (B) a polymerization initiator system, wherein the polymerization initiator system comprises (B1) a sensitizer, (B2) a compound represented by the following formula (I):Z-R(I) [In the formula, Z is represented by the following formula (II):R1(Ar) P-(II) (Wherein, R1 Represents a substituted or unsubstituted hydrocarbyl group, Ar represents a substituted or unsubstituted aryl or heteroaryl group, R represents an aryl group, and examples thereof include a hydroxyl group, an amino group,-NR2R3Group (wherein R2And R3May be the same or different from each other, and C1-6An alkyl group), a carboxyl group, and a group having a polymerizable double bond, and may be substituted by one or more groups selected from In the formula, R1Group and the Ar group are a hydroxyl group, an oxo group,-NR2R3Group (wherein R2And R3May be the same or different from each other, and a hydrogen atom and C1-6An alkyl group, a carboxyl group, and a group having a polymerizable double bond, and may be substituted with one or more groups selected from L represents a hydroxyl group, an oxo group,-NR2R3Group (wherein R2And R3May be the same or different from each other, and a hydrogen atom and C1-6And an aromatic tertiary phosphine compound of the formula ## STR3 ## wherein R 1 is selected from alkyl groups, carboxyl groups and one or more groups selected from groups having polymerizable double bonds , And a dental composition.本発明は、光硬化歯科用組成物を製造するための、第三級ホスフィン化合物を含む重合開始剤系を含む歯科用組成物、及び前記芳香族第三級ホスフィン化合物の使用方法に関する。具体的には、本発明は歯科用組成物であって、 (a) 少なくとも1つの重合性二重結合を有する1つ又は複数の化合物と、 (b)
