A composition including nanoparticles each having an acidic polymerizable siloxane moiety. For example, a hydrolysis stable, self-etching, self-priming dental adhesive composition including 90 to 10 percent by weight of an aqueous phase, and 10 to 90 percent by weight of acidic polymerizable nanoparticles. The acidic polymerizable nanoparticles are obtainable by hydrolysis of a mixture containing one or more hydrolyzable organosilicon compounds wherein (i) at least a portion of the hydrolyzable organosilicon compounds contains one or more polymerizable groups and (ii) at least a portion of the hydrolyzable organosilicon compounds contain one or more acidic moieties.