Abstract : In recent years, the root canal treatment-tools made from Ni-Ti alloy have spread. There is the NT-condenser which is used to fill the root canal among them.

 The action of this NT-condenser is to twist around heat-softened gutta percha and carry it in the root canal and detach gutta percha by the friction between its rotation and the surface of the root canal. By this method gutta percha is carried to the apex of root.

 We have thought that there is a relation between the roughness of the surface of the root canal and the flow of the heat-softened gutta percha, then we have measured the relation between the compress test and the roughness of the surface of the root canal and treated statistically.

 As the results next matters are made obvious. When the heat temperature of gutta percha is constant and filled in the root canal, rougher the surface of the root canal the flow is worse. And the significant difference among the three lots can not acknowledge.

Abstract : It is reported that there is same difference in tenacity among the lots of even same production when the flow test of the root canal filling material of the gutta percha on the market is operated.

 We have operated the root canal filling by the meathod of the NT-condenser with the different lots of the obturation gutta-NT and have investigated the effect of the difference of tenacity on the sealing ability of the apex of root by the dye-stuff permeation test, and have the following results.

 The feeling of operation and the sealing ability of the apex of root among the three kind of lots on the market can not be acklowledged when the temperature control is accurate in the method of the NT-condenser.

Abstract : Hydrogen peroxide (H₂O₂) has been used for tooth bleaching. Especially, superoxol has been used for waking bleach technique. However, details of bleaching mechanisms using H₂O₂ have not been clarified yet. In this experiment, the root canal dentin surfaces were observed using SEM after applied several concentrations of H₂O₂ on root canal dentin. In the results, the intertubular dentin and peritubular dentin were resolved by high concentration of H₂O₂, and long time application of H₂O₂.

Abstract : In this case the root canal was filled by lateral condensation technique with sealer and gattapercha (G・P) 25 years ago.

 Since then sealer and G・P had been absorbed bit by bit, and the patient came again with pain.

 This time the root canal was filled by vertical condensation technique with GP but without sealer.

 A satisfactory result was obtained.

Abstract : Endodontic therapy of internal root resorption is very difficult. Therefore usually internal root resorption teeth is been extracted. This case has been treated by nonsurgical antibiotic endodontic therapy. For 12 years have been observated and no problem is founded.

Abstract : The odontogenic maxillary sinusitis is usually occurred via the maxillary molars. Tooth extraction and/or maxillary sinusectomy are performed in order to treat such the odontogenic maxillary sinusitis. Periapical lesion, periodontitis or accident of root canal treatment are also bring about the odontogenic maxillary sinusitis. However, no details of suggestions for the treatment are available for the root canal treatment on the odontogenic maxillary sinusitis in the textbook of endodontics. This case report is success case for the healing of the odontogenic maxillary sinusitis by endodontic therapy and drugs used.

Abstract : In our clinic we’ve investigated the relation in which we’ve had interest between a habit of life include a dietary life and health. When we visited the Republic of Kenya on February 2000, we went into the village of the Masai tribe and examined their oral cavity, a posture of the whole body, a countenance and a dietary life and so on. We report we learned original statue of human being from them through their state of teeth and gingiva and arch of teeth. And we consider the problem of physical degeneration which has now rapidly increased in Japanese by comparing with them under this investigation.