Two root canal filling materials, consisted chiefly of calcium hydroxide and iodoform, "Calvital" and "Vitapex" were used to the teeth of a 78-year-old man and an 82-year-old woman respectively. One or two years later these teeth with alveolar bone were resected from the patients died, and observed histopathologically. 1. These human materials especially periapical tissues to which applied "Calvital" and "Vitapex" were thought to be the first cases examined histopathologically. 2. In 6 "Calvital" cases, 3 cases with enlargement and cleaning of the root canals before filling showed a good healing, and 1 case with the same treatment was nearly good, but 2 cases without this root canal treatment showed not so good. 3. The "Vitapex" case was only one, in which the root canal filling was carried out after the pulp extripation. The apical foramen was closed by an osteoid hard tissue, meaning a success healing. 4. In this "Vitapex" case, the patient was old and laid up with illness soon after the filling. Therefore this success healing may be suggested that "Vitapex" is excellent for root canal filling and that the cells in periodontal ligament of such an aged patient still have a capacity of differentiation to osteoblasts or.cementoblasts. 5. Clinically it may be noticed that in the radiograph the disappear of radiopaque materials in the root canal does not mean disappear of calcium hydroxide but of iodoform
