The present invention provides a patch which is attached to a tooth or the area around a tooth, the patch comprising a drug layer and support layer, wherein the patch can easily be removed by tooth brushing alone because the support layer comprises: a polymer which absorbs water such that the tensile strength reduces by more than 50% relative to before the water absorption, or else of which the static contact angle changes as time passes, or else which has a solubility parameter of between 5 and 22 (MPa)1/2; and a polymer of which same is between 23.5 and 40 (MPa)1/2. The patch is able to be easily removed by tooth brushing.