乳歯根管充填に関する実験的研究

Abstract

In an experimental study of root canal filling in deciduous teeth, a cytotoxic test by the tissue culture method and a histopathological test in deciduous teeth of dogs were made with use of preparation of calcium hydroxide (Calvital), iodoform calcium hydroxide (Vitapex), and zinc oxide eugenol (Neodyne [○!R]). The results were as follows : 1. In the cell multiplication test, Calvital and Neodyne [○!R] markedly inhibited proliferation at 50% and 20% concentrations. Vitapex however showed only slight inhibition at every concentrations. 2. Calvital and Neodyne [○!R] showed active proliferation and recovery phenomenon in the third to fifth days. 3. In morphological changes, the reaction zone of cells was the most narrow one for Vitapex and its changes in pH of the medium were negligible. Calvital changed pH of the medium to high alkalinity and its reaction zone of cells was relatively width. Neodyne [○!R] also changed its medium to alkalinity and its reaction zone of cells was the widest and spreaded on nearly all surface of the Petri dishes. 4. In histopathological investigations, Calvital and Vitapex showed almost no inflammatory changes in the periodontal membrane. Neodyne [○!R] however induced inflammatory changes. 5. When the preparation was exudated through the apical foramen, Calvital and Vitapex showed very slight inflammatory cell infiltration limited to the periodontal membrane. For Neodyne [○!R], formation of abscess was observed. 6. On a longer term, the trend for inflammation disappeared and turned for healing for each preparation. 7. Vitapex showed vacuolar formation, as a specific change in the apical periodontal membrane. 8. In the cases where the exudated preparation approached the alveoler bone, necrosis of bone tissue, and degeneration and disappearance of osteoclast were observed in part. 9. Delay in resorption of deciduous root in the filled side was recognized for each preparation, but no distinct difference was found among these preparations.