You should always use regular toothpaste daily to brush your teeth with but yes you can use coconut oil to brush your teeth with as well.
I brush my teeth everyday using regular toothpaste but then every other day I will also brush my teeth with coconut oil as well which helps to remove bacteria and help prevent gum disease and tooth decay.
Coconut oil also helps to keep my teeth white and you can also oil pull for extra benefits to clean your teeth.