Abstract : In 1993, the new automated thermatic condensation technique with Multi-phase gutta-percha and NT (material as nickel-titanium) condenser on a contra angle electric engine was introduced by McSpadden. This technique enable to seal root canal obturation of even complex root canal quickly.

 But, a cost of Multi-phase gutta-percha is expensive, so Multi-phase gutta-percha was not popularized. There, we thought of a utilization of a cheap Obturation gutta with NT condenser for root canal filling.

 The purpose of this study was compare the sealing ability of Obturation gutta by NT condenser ( : Obturation technique) with lateral condensation technique, Multi-phase gutta-percha by NT condenser ( : Multi-phase technique), main gutta-percha point and Obturation gutta by NT condenser ( : Hybrid technique).

 The root canals of seventy-seven extracted mandibular incisors were endodontically prepared and obtrurated by the four techniques and immersed in the India ink. The penetration distance of the dye was measured from apex of the root.

 The results were as follows :

 1. The penetration distance of dye on obturated root canals were observed with order of Hybrid technique, Obturation technique, Multi-phase technique, lateral condensation technique. However, at a penetration distance, there were not difference among result of Mann-Whitney U-test, each.

 2. At Obturation technique and Multi-phase technique, it was 57.9% that there were not penetration of dye from apex of the root. Hybrid technique was 47.4%, lateral condensation technique was 45.0%.

 3. Obturation technique and Multi-phase technique were judged, as there were capability for apical seal by two-way analysis (test for the proportion). But, the lateral condensation technique occurred question against a capability.

 4. By the test of the curve of life (generalized Wilcoxon test) used to assess the effect of treatment, there was no difference between Obturation technique and Multi-phase technique. And then, lateral condensation technique was slightly inferior from the formers.

 Finally, the automated thermatic condensation technique depend on Obturation gutta and NT condenser proved to be effective in sealing the apical foramen.

Abstract : On the precedent report, the authors pointed that the obturation technique by Obturation gutta with NT condenser was good ability for seal apical foramen. With this Obturation gutta is apt to become over obturation when the narrow part of the apical foramen is above #35.

 The purpose of this study was to investigate the root canal obturation depending on Obturation gutta with NT condenser an influence for sealing ability and size of apical foramen.

 The materials were seventy-seven mandibular incisors extracted teeth which were devided into three groups.

 Group 1 : #15 apical foramen, moreover as were endodontically prepared at working length (1 mm short of the apex) to a #50 file (apical seat).

 Group 2 : #30 apical foramen, moreover as instrumented for apical seat of #70.

 Group 3 : The teeth had #40 apical foramen, moreover as prepared for apical seat of #80.

 We filled these standardized root canal with the automated thermatic condensation technique depend on Obturation gutta and NT condenser, then immersed in the India ink. The distance of the dye penetration was measured from apex of the root.

 The results were as follows :

 1. The mean value of ink penetration. Group 1 : 0.68 mm. Group 2 : 1.05 mm. Group 3 : 0.78 mm. There was no statistically difference between the groups with result of Mann-Whitney U-test.

 2. Group 1 : no penetration of dye from apex of the root was 63.0%. Group 2 and group 3 were 68.0%.

 3. The evaluation of this technique was good sealing ability for apical seal by two-way analysis (test for the proportion).

 4. This technique was imagined the rate of over filling from apical foramen and size.

 5. By the test of the curve of life (generalized Wilcoxon test) used to assess the effect of treatment. No statistically significant differences were observed among 3 groups. But, group 1 was a little superior from others.

Abstract : Usually, NaClO and H₂O₂ are used for root canal irrigation in Endodontic therapy. When CuCl₂ was added to H₂O₂, hydroxyl radical, the most destructive active oxygen, was generated. Hydroxyl radical generated from CuCl₂ and H₂O₂ mixture has bactericidal effect. We studied the effect of CuCl₂ and H₂O₂ mixture on smear layer using SEM. When the sample bearing smear layer on root canal was immersed in CuCl₂ and H₂O₂ mixture, smer layer was not removed. After washing the root canal, smear layer’s substance changed to hyaloid structure. This hyaloid structure was not removed by NaClO, but by EDTA. After removal of hyaloid structure by EDTA, dentinal plug like substances were observed in the dentinal tubules.

Abstract : In the endodontic therapy, endodontists must have caution for prevention of dental accident. Especially, the relation between maxillary sinus and clinical root is important. Sometimes, molar and premolar roots perforate in maxillary sinus. In this case report, remained gutta percha in maxillary sinus was pursued for over five years. In the case 1, the first root canal treatment of palatal root canal of upper right first molar, over filled gutta percha point was cut off. The point remained in maxillary sinus. After seven weeks, patient has incompatibility in nose, and he excreated pituita. Then, remained gutta percha point was checked by taking X-ray before root canal filling, and gutta percha point disappeared from maxillary sinus. The gutta percha point might be excreted from maxillary ostium. After five years, patient has no problem on maxillary sinus and tooth. In the case 2, root canal filling for upper left second molar, gutta percha mass was overflowed from apical foramen of palatal root. The aberrant gutta percha mass was found in maxillary sinus. After six years, gutta percha mass disappeared from maxillary sinus. The gutta percha mass might be excreted from maxillary ostium. After six years, patient has no problem on maxillary sinus and tooth.

Abstract : It is necessary to investigate primarily the strength relation between inflammation factor and the host when we discuss the infectious disease. The effort to make sterile inside of the root canal and the application of the culture test to confirm the sterile state are very important, but they are the approach only from the factor of origin side. Namely, it is thought that the approach from the power of resistance of the host side is lacking in the former way of thinking.

 In the Otani Endodontics which we practice, we exclude the inflammation bacteria and remove the organic component such as the layer of predentin by the mechanical root canal formation and we endeavor to remove the every inflammation factor in the root canal and to make sterile. However, we thought that the mechanical sterilization is impossible, so we made it our object to accomplish the state of the mechanical disinfection. Then, as for the insufficient sterilization, the root canal packing without any dead space is performed by the Obturation System which is the vertical condensation filling method and its modification and it is thought that the root canal treatment is guided to success in the result. We leave the movement of last healing to the homeostasis of a living body and it is necessary to us the view point of the way increase the power of resistance of the living body and prevent to be taken sick and guide the healing.

 I will report here the practice and the results of the Otani Endodontics which has the above-mentioned conception.