The invention relates to adhesive compositions that exhibit a significant decrease in polarity upon polymerization. More specifically, it relates to curable self etching dental adhesive compositions that can be applied to the tooth hard substance in one step and exhibit this decrease in polarity upon curing. In this respect a formulation is provided combining phosphoric acid esters bearing substituents with one ethylenically unsaturated moiety on the phosphorus atom and phosphoric acid esters bearing substituents with two or more ethylenically unsaturated moieties on the phosphorus atom.