Orthodontic bracket and manufacturing method thereof

#1. Field of the Invention

#The present invention relates to an orthodontic bracket used in orthodontic treatment and a manufacturing method thereof. More specifically, the present invention relates to an orthodontic bracket having a bonding surface that has excellent adhesiveness to a tooth surface, and a manufacturing method thereof.

#2. Description of the Related Art

#FIG. 1 is an external view of an orthodontic bracket of the present invention;

#FIG. 2 shows a section along A-A in FIG. 1, and is a sectional view of the orthodontic bracket before undercut formation;

#FIG. 3 is a plan view of the bracket of FIG. 2 showing a bonding surface of the bracket;

#Following is a description of embodiments of the present invention with reference to the drawings. FIG. 1 is an external view of an orthodontic bracket 1 of the present invention. FIG. 1 shows a transparent synthetic resin hook-type bracket having two sets of wings 2. A gold-plated metallic groove member 3 is provided in a central part. Although not shown, arch wire is supported in this metallic groove member 3. There are many other types of such a bracket, for example a single bracket, or a bracket having a different shape such as a bracket in which the metallic groove member has an extension part, but for the embodiments of the present invention, description will be given assuming a hook-type bracket.

#After the arch wire has been inserted into the metallic groove member 3, installing wire is wound around the wings 2, thus fixing the arch wire to the bracket 1. There are various types of the bracket 1; the torque, angulation and so on for the bracket 1 differ according to the site of the tooth on which the bracket 1 is to be installed, for example according to whether the bracket 1 is for a canine tooth or a central incisor, and the shape differs according to the orientation and so on of the tooth to be straightened. A lower surface of the bracket 1 is a bonding surface 4 that is bonded to the tooth surface using an adhesive. The constitution of the bracket 1 of FIG. 1 is such that recessed parts 4a and protruding parts 4b are formed on the bonding surface 4, and after this undercuts 5 are provided. The structure and function of the main body of such brackets 1 is described in detail in, for example, Japanese Patent Application Laid-open No. 9-544 and Japanese Patent Application Laid-open No. 11-206783, and hence detailed description will be omitted here. The present invention relates to the constitution of the bonding surface 4 for bonding such a bracket 1 to a tooth.

#FIG. 2 shows a sectional view along A-A of the bracket 1 shown in FIG. 1. As described above, the bottom of the bracket 1 is a bonding surface 4 that is bonded to a tooth, and has a constitution in which recessed parts 4a and protruding parts 4b are arranged alternately. For explanatory purposes, FIG. 2 has been made to be a drawing that shows the state before the undercuts are formed, and hence there are slight differences to the external view of the completed state in FIG. 1. FIGS. 3 and 4 are plan views showing a side of the bracket shown in FIG. 2; FIG. 3 is a drawing in which the recessed parts 4a and the protruding parts 4b are arranged in a cross shape, and FIG. 4 shows a state in which the undulating shape of a joining surface (or a bonding surface) 11 of a completed bracket 10 is formed as parallel lines.