A three-in-one tooth-cleaning device structured as a toothpick, an interdental brush, and a floss pick includes a main body and an interdental elastic-bristle portion. The main body is integrally formed of a first plasticized material by injection molding and is structured as a floss pick at one end and as a toothpick at the opposite second end. The interdental elastic-bristle portion is integrally formed by injection molding a second plasticized material over the periphery of the main body in a section adjacent to the second end of the main body and forms a plurality of bristles. The second plasticized material has a lower hardness than the first plasticized material. The three-in-one tooth-cleaning device can be carried around to perform diversified, thorough, and effective removing operations on the dental plaque or food debris on and/or between teeth anytime and anywhere to prevent dental caries (especially interdental caries) and periodontal disease.
