根管内器具破折の処置について

―イオン導入後における歯質内金属分布の透明標本による観察―

抄録

The extracted human teeth with a broken reamer in the root canal were embedded in agar and treated by iontophoresis with 3% ammoniacal silver nitrate. By means of transparent specimens, the distribution of the metal ion in the teeth was observed with a stereoscopic microscope. The results obtained were as follows: 1) In the case with a black stain in the agar, the silver ion was reached the root apex. The canal wall from the area with a broken reamer was stained black on the apical side and the electric resistance of the teeth was increased. 2) In the case with a brown stain in the agar, the ferric ion of the reamer which broke in the root canal was eluted. The canal wall from the area with a broken reamer was stained brown on the apical side and the electric resistance of the teeth was decreased. 3) In the case with a black and brown stain in the agar, both the silver ion and the ferric ion of the reamer which broke in the root canal reached beyond the root apex. The canal wall from the area with a broken reamer was stained black as well as brown on the apical side and the electric resistance of the teeth was increased. 4) In the case without any stain in the agar, nothing reached the apical region. However, a black stain was observed in the dentin in the cervical region of the teeth and the electric resistance of the teeth was increased.