Dental materials based on polymerizable binders, which contain at least one
chromophoric xerogel of the formula I:
(SiO.sub.2).sub.a (SiO.sub.1.5 -Sp-X-CG)(Me.sub.n O.sub.m).sub.b (I)
in which Me represents a main-group metal of the 2.sup.nd to 3.sup.rd main
groups or a transition metal of the 4.sup.th sub-group of the periodic
table of elements; n being equal to 1 or 2, m being equal to 1 or 2 if n
is equal to 1 and m being equal to 3 if n is equal to 2; Sp is a C.sub.1
to C.sub.10 alkylene radical or C.sub.2 to C.sub.10 oxyalkylene radical
with 1 to 4 oxygen atoms or is absent; X is a compound group, such as
CO--O, O--CO, CO--NH, NH--CO, O--CO--NH, NH--CO--O, NR, O or S or is
absent, R being hydrogen or a C.sub.1 to C.sub.5 alkyl radical; CG is a
chromophore; a is an integer from 0 to 20 and b is an integer from 0 to 5.
