Photocurable dental composition comprising(a) one or more radical-polymerizable monomers, and(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 (I): R1R2R3X(CO)X'R4R5R6 (I)whereinX and X' which may be the same or different, independently represent Si or Ge,R1, R2, R3, R4, R5, and R6, which may be the same or different, independently represent a hydrocarbon group having 1 to 20 carbon atoms, whereby any two hydrocarbon groups of R1, R2, R3, R4, R5, and R6 may be bonded to each other and form together with either X, X' or the moiety X(CO)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(CO)X' moiety, or- be substituted by on 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.
