Methods and kits for removing calculus from a tooth, wherein the method can include applying a component A to the tooth, wherein component A comprises a hydrogen peroxide or a precursor thereto; applying a component B to the tooth, wherein component B comprises a non-enzymatic, hydrogen peroxide decomposition catalyst for generating oxygen gas; wherein components A and B are applied simultaneously or sequentially to the tooth, thereby generating oxygen gas to soften and/or loosen at least part of the calculus on the tooth; and removing at least a part of the calculus from the tooth.