| 摘要 |
<p>PURPOSE:To reduce the contact area with a jaw bone of the outer side surface of a blade part, to reduce the generation quantity of friction heat and to enhance the cutting property of a drilling tool for dental treatment, by forming the outer side surface of the blade part into a saw-tooth shape. CONSTITUTION:A notch part is formed to the side surface of the cylindrical blade body 3 provided to the lower end of the support shaft of a drilling tool and a blade part 5 is formed to the lower end of the blade body 3. The outer diameter of the blade part 5 is made larger than that of the blade body 3 and the leading end surface of the blade part 5 is formed into a saw-tooth shape. Further, the outer side surface of the blade part 5 is formed into a saw-tooth shape to form a lateral cutting blade 11 and the contact area with a jaw bone of the side surface thereof is reduced. As a result, the friction resistance of the outer side surface of the blade part 5 can be made small and the generation quantity of friction heat can be reduced and the cutting property of the drilling tool can be enhanced. Further, the saw-tooth cutting blade of the side surface of said blade part is inclined with respect to the axial direction of the blade body and a space is formed between the leading end of the blade part and the blade body. Therefore, chips can be well discharged and cooling water becomes easy to reach a place to be cut.</p> |
