抄録
As one of the types of endodontic endosseous implants, taper pins are often employed. In implanting taper pins, reamers or drills are used for enlarging the root canal exteriorly and preparing the canal taper. In this study, four operative techniques (methods A to D) are assessed from the viewpoint of the compatibility of taper pins with the canal walls.
Method A: Drills are primarily used.
Method B: Hand reamers
Method C: General method (KYOCERA method)
Method D: Engine reamers
Materials used in this experiment include acrylic resin plates and extracted upper incisors. The compatibility was examined by use of Indian ink.
The resalts are as follows:
1. The compatibility between the taper pins and the canal walls created through the acrylic resin plates was not always satisfactory. The penetration of Indian ink was observed in the taper portions prepared by any of the four methods to a depth of 3 mm above the canal apices and in the straight portions further above.
However, method A was significant in that the penetration of ink was almost limited within the 3 mm taper portion.
2. As regards the damage to the root apices, in every method cracks and/or splinters occurred during the processes of perforating the root,enlarging the root canal and preparing the canal taper. The number of cracks and splinters was significantly smaller in methods A and D than in method C. The lengths of the cracks found after using methods A, B,and D were 0.2～2.39 mm shorter than those found after using method C. The lengths of the splinters found after using method D were significantly smaller by 0.08～0.25 mm than those found after using methods A, B, and C.
3. The damage occurred frequently when a 13 P drill (35%), an A-reamer (22.3%) and a hand reamer (17.6%) were used.A modified A-reamer and a B-reamer caused damage frequently……4.1% and 2.0%, respectively. No damage was wrought by a 17 P drill.
In conclusion, these results indicate that much improvement should be made on the instruments used for taper pin implantation.
