露出損傷歯髄に対する各種覆髄剤の治癒効果に関する実験的研究

抄録

This study was carried out to investigate the healing effect of various pulp capping agents on the exposed pulp using the calcium hydroxide preparations such as Calvital, Dycal, Hydrex and pure calcium hydroxide and a zinc oxide eugenol preparation such as Cavitec in the lower molars of dogs. The results were as follows : 1. With Calvital, Dycal and pure calcium hydroxide, the dentin barrier formation, which was considered as an ideal healing process, occurred in most of the cases after fourteen days. However, no dentin barrier formation was observed with Hydrex and Cavitec. 2. The dentin barrier formation was classified into six types according to its structure and the rate of inducing the dentin barrier formation was estimated in each material. It was observed that the dentin barrier was mostly Types I and II in the teeth treated with Calvital and there were few Types IV and V with the amorphous structure, and the dentin barrier with the best quality was formed. The dentin barrier formation of Types I and II decreased in the teeth treated with Dycal, and the teeth treated with pure calcium hydroxide showed a greater decrease. With Hydrex and Cavitec, no Type I or II was formed and the formation of Types IV and V was observed. 3. The dentin barrier formation of Types I and II, which indicated the structure of dentin, occurred only where a necrotic zone and a border zone were evident in the superficial layer of the pulp contacting the capping agents. 4. In the pulpal inflammatory response with five agents, a mild cell infiltration was observed in early stages and gradually subsided with the least irritation in the teeth treated with Calvital. The severity was similar in the pulps treated with Dycal and pure calcium hydroxide. In the pulps treated with Cavitec a cell infiltration was severer than those in the pulps treated with Dycal and pure calcium hydroxide, and the pulps treated with Hydrex showed the severest inflammatory response and the suppurative inflammation in many cases even with a long term observation. 5. In the occurrence of the degenerative changes in the pulps with five agents, the pulps treated with Calvital showed the least rate followed by the pulps treated with Dycal, pure calcium hydroxide or Cavitec, which did not vary greatly in findings, and the pulps treated with Hydrex presented the most manifestiations.