| 摘要 |
PURPOSE: A bone screw for medical care is provided to increase the self-drilling, self-tapping and release-preventing function, as well as the wire hauling and screw fastening characteristic, and to overcome the defects of the existing medical screw. CONSTITUTION: The bone screw for a dental correction includes: a screw drilling portion(10); a body portion(20), extended from the drilling portion(10); and a head portion(30), extended from the body portion(20). The drilling portion(10) has a vertex angle of 35 deg. to 45 deg., starting from a center line so as to drill the bone, using the end of the bone screw. A cutting flute is formed from the drilling portion(10) to the body portion(20), and a continuous thread is formed on an outer circumference of the body portion(20), starting from the drilling portion(10). The body portion(20) is twice stepped and tapered so that it has a first and a second body segment. The release torque of a thread, formed on the both portion(10,20), is greater than the insertion torque thereof.
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