Photocurable dental composition comprising (a) one or more radical-polymerizable monomers, (b) 0.1 to 7.0 percent by weight based on the total weight of radical polymerizable monomers in the composition of a compound of the following formula: R 1 R 2 R 3 X X'R 4 R 5 R 6 wherein X and X' which may be the same or different, independently represent Si or Ge, R 1, R 2, R 3, R 4, R 5, and R 6, which may be the same or different, independently represent a hydrocarbon group having 1 to 20 carbon atoms, whereby any two hydrocarbon groups of R 1, R 2, R 3, R 4, R 5, and R 6 may be bonded to each other and form together with either X, X' or the moiety X X' to which they are attached a 3 to 12- membered heterocyclic ring, whereby any of the hydrocarbon group or the heterocyclic ring may - contain one or more keto groups other than the keto group of the X X' moiety, or - be substituted by one or more groups selected from halogen atoms, a cyano group, an amino group, or a hydroxy group, and - in case the hydrocarbon group or the heterocyclic ring contains an alkylene chain or an alkenylene chain, one or more carbon atoms in the alkylene chain or alkenylene chain may be replaced by an oxygen atom, a sulfur atom, an amide group, an ester group, a urethane group or an NH group, and (c) a particulate filler and/or solvent, which contains an iodonium salt as an additional initiator. (a) one or more radical-polymerizable monomers, (b) 0.1 to 7.0 percent by weight based on the total weight of radical polymerizable monomers in the composition of a compound of the following formula: R 1 R 2 R 3 X X'R 4 R 5 R 6 wherein X and X' which may be the same or different, independently represent Si or Ge, R 1, R 2, R 3, R 4, R 5, and R 6, which may be the same or different, independently represent a hydrocarbon group having 1 to 20 carbon atoms, whereby any two hydrocarbon groups of R 1, R 2, R 3, R 4, R 5, and R 6 may be bonded to each other and form together with either X, X' or the moiety X X' to which they are attached a 3 to 12- membered heterocyclic ring, whereby any of the hydrocarbon group or the heterocyclic ring may - contain one or more keto groups other than the keto group of the X X' moiety, or - be substituted by one or more groups selected from halogen atoms, a cyano group, an amino group, or a hydroxy group, and - in case the hydrocarbon group or the heterocyclic ring contains an alkylene chain or an alkenylene chain, one or more carbon atoms in the alkylene chain or alkenylene chain may be replaced by an oxygen atom, a sulfur atom, an amide group, an ester group, a urethane group or an NH group, and X and X' which may be the same or different, independently represent Si or Ge, R 1, R 2, R 3, R 4, R 5, and R 6, which may be the same or different, independently represent a hydrocarbon group having 1 to 20 carbon atoms, whereby any two hydrocarbon groups of R 1, R 2, R 3, R 4, R 5, and R 6 may be bonded to each other and form together with either X, X' or the moiety X X' to which they are attached a 3 to 12- membered heterocyclic ring, whereby any of the hydrocarbon group or the heterocyclic ring may - contain one or more keto groups other than the keto group of the X X' moiety, or - be substituted by one or more groups selected from halogen atoms, a cyano group, an amino group, or a hydroxy group, and - in case the hydrocarbon group or the heterocyclic ring contains an alkylene chain or an alkenylene chain, one or more carbon atoms in the alkylene chain or alkenylene chain may be replaced by an oxygen atom, a sulfur atom, an amide group, an ester group, a urethane group or an NH group, and - contain one or more keto groups other than the keto group of the X X' moiety, or - be substituted by one or more groups selected from halogen atoms, a cyano group, an amino group, or a hydroxy group, and - in case the hydrocarbon group or the heterocyclic ring contains an alkylene chain or an alkenylene chain, one or more carbon atoms in the alkylene chain or alkenylene chain may be replaced by an oxygen atom, a sulfur atom, an amide group, an ester group, a urethane group or an NH group, and (c) a particulate filler and/or solvent, which contains an iodonium salt as an additional initiator.