| 摘要 |
The invention relates to a rotatable file dental treating device (1) which is driven by a motor (2) and comprises means (3, 18) for determining a root-canal position instruction related to a tooth apex, means (4) for stopping the motor according the file (1) position with respect to said position instruction and first means (5, 6) for measuring and calculating the canal length (L) remaining between the file and the position instruction, wherein the inventive device comprises second means (7, 7a, 7b) for calculating a value (D) derived from the remaining canal length and third means (8, 8a, 8b, 8c, 8d, 8e) for combining the derived value and the remaining canal length and the combination of the derived value and the canal length produced by the calculating means (6, 7, 8, 8a, 8b, 8c, 8d, 8e) controls the motor turn-off in such a way that the rotation of the file is stopped in anticipation of the position instruction. |
