| 摘要 |
The invention relates to a root canal instrument for preparing a housing for a pivot inside dental roots, characterised in that it comprises a working part extending along a longitudinal axis, a cross-section of a frustoconical envelope of the working part embodying an elliptical section or an ovoid section or an oblong section or a section of the type comprising a front circle portion (20) and a rear circle portion (30) joined by two side bend portions, a diameter (2) of the front circle portion (20) being longer than or equal to a diameter (3) of the rear circle portion (30). |
