Abstract: A dental adhesive composition which can quickly be hardened even in the presence of oxygen without using a radical generating agent such as a peroxide or a photopolymerization initiator, to give high bond strength, the composition including, in specific amounts, (A) a carboxylic acid compound having a (meth)acryloyl group and a carboxyl group, both of which are attached to an aromatic ring; (B) a bisphenol A derivative having two (meth)acryloyl groups; (C) a hydroxylalkyl (meth)acrylate; (D) a (meth)acrylate derivative having an acid group; and (E) at least one polymerization initiator selected from the group consisting of aromatic amines, aliphatic amines, and aromatic sulfinic acids; the composition being substantially free from any radical polymerization initiator.

Abstract: A dental filling composite material is disclosed, which contains 10-99% by weight of phosphazene of the formula: ##STR1## in which at least one of R.sub.1 and R.sub.2 represent radicals having not less than 3 carbon atoms and being polymerizable.The filling composite material is low in polymerization shrinkage, thermal expansion coefficient and water absorption and may be quickly polymerized and cured to form a polymer of high compressive strength, flexural strength and hardness.