The present invention relates to a controlled release device for oral cavity, which is attached on a hard dental surface of a tooth. The attachment is done using any adhesive layer that can attach on enamel surface of a tooth or using a holder attached to the hard dental surface, to which holder the device can be attached, clipped or fastened. The device comprises of two or more polymeric materials forming a polymer matrix or matrices. The polymer matrices incorporate one or more agent(s), which release rate in the oral cavity can be con-trolled with the polymeric materials in the matrices. The invention also relates to a method producing a controlled re-lease device for delivering an agent to the oral cavity