Yes, they have teeth in rows just like sharks. The ones in back are often larger and more abrassive then the ones toward the front. an adult stingray sucking the the side of your arm is a sure way to clean any hairy regions. The males are often going to have larger teeth to hold on to the female during mating.
Furthermore there entire body are covered in teeth. Called denticles you can see the bumps on the rays backside. Cool huh!