Composites comprising(A) general formula (I), compound of ##STR1## [in the formula, R.sub.1 indicates either hydrogen or methyl group and R.sub.2 indicates hydrogen, alkyl radical with carbon number 1-5 to be possibly substituted with halogen, alkyleneoxide group with carbon number 2-4 to be possibly substituted with halogen or --(CH.sub.2 CH.sub.2 O)nH group (n=integral number of 1-4) to be possibly substituted with either halogen or methyl group],(B) vinyl compounds and/or silane compounds, and optionally(C) free radical developing agent and/or light sensitizer have not only an excellent adhesiveness but anti-irritation and anti-harmfulness against tissue, pulp and the like, for teeth and dentin.