• Restorative Dentistry and Endodontics
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• v.1 no.1
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• pp.43-49
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• 1975

This study was divided into two parts. In the first experiment, the in vitro antimicrobial effect was tested in order to evaluate the effect of vapors, and the effectiveness of the nonspecific endodontic medicaments (formocresol, camphorated parachlorophenol and eugenol). In the second experiment, the intracanal effect was tested in vitro under simulated clinical condition. The actual bactericidal effect of the nonspecific endodontic medicaments (formocresol, camphorated parachlorophenol and eugenol) was quantitated. The results were obtained as follows: 1. The zone of inhibition was appeared on the vapors of formocresol only, however there were no zone of inhibition appeared on the vapors of camphorated parachlorophenol and eugenol. 2. Formocresol produced the widest zone of inhibition and eugenol, the next and camphorated parachlorophenol, the narrowest. 3. All of the tested medicaments were vaporized in the root canal. They proved to be the effective antimicrobial activity in the root canal. 4. All of the tested medicaments were showed more bactericidal effect at 72 hours than 48 hours. 5. In comparing with the bactericidal effect of the tested medicaments in the root canal, formocresol was showed the most bactericidal medicament, camphorated parachlorophenol was showed the least. 6. Complete sterilization of the root canal was not achieved in any medicaments applied in this study.

• Restorative Dentistry and Endodontics
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• v.15 no.1
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• pp.97-105
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• 1990

When conventional root canal treatment is failed or contraindicated, retrograde root canal filling following apicoectomy is a valuable procedure, aimed at hermetically sealing the root canal against leakage of irritants from the canal into the periapical tissue. In this in vitro investigation, to analyze apical microleakage electrochemically in teeth with different retrograde filling materials and preparation types, single - rooted tooth was cut 2mm from the apex and each Class I and Slot preparation was prepared. Experimental groups : Group 1. Amalgam filling with cavity varnish in Class I preparation Group 2. Scotchbond 2+Silux filling in Class I preparation Group 3. Gutta percha filling with ZOE cement in Class I preparation Group 4. Amalgam filling with cavity varnish in Slot preparation Group 5. Scotchbond 2+Silux filling in Slot preparation Each specimens was immersed in 1% solution of KCl, and applied a potential of 9V external power supply. Measurements of the current flow were obtained at 1, 2, 3, 7, 9, 12, 14, 18, 21, 25 and 28 day after immerson. Marginal microleakage were compared and evaluated. The results were as follows ; 1. The group filled with composite resin with dentin bonding agent shows lower apical microleakage value than the group filled with amalgam following varnish application (P<0.01). 2. In the group filled with gutta percha, apical microleakage value was the hightest 3. There was no significant difference between Class I cavity and Slot type cavity regardless of the used materials.

• Restorative Dentistry and Endodontics
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• v.25 no.3
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• pp.474-482
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• 2000

Currently frequency-dependent type electronic apex locators have been widely used to determine the working length in endodontic treatment. But, accuracy of electronic apex locators is controversial. The purpose of this study was to evaluate the accuracy of Root-ZX(Morita Co., Japan) at different kinds of conditions of root canals compared with the radiographic working length. The 40 extracted human anterior teeth with fully formed apices and without any caries were used. The radiographs were taken for working length with the 0.5mm short of #15 K-file tip just visible at the foramen under the surgical microscope(Carl Zeiss Co. Germany) at 25X. Then the electronic working lengths were determined with Root-ZX at the different kinds of conditions of root canals according to the presence of electrolyte and Crown-down pressureless technique. The results were as follows ; 1. There was no significant statistical difference in working length between radiograph and Root-ZX. 2. There was no significant statistical difference in electronic working length between the canal with electrolyte and without electrolyte. 3. There was no significant statistical difference in electronic working length between the canal without any instrumentation and after Crown-dow pressureless technique. 4. Of the total 40 root canals, 85% in Group I, 92.5% in Group II, 95% in Group III and 95% in Group IV using Root-ZX showed coincidence within 0.5mm accuracy compaing with the radiographic working length. The results showed that the Root-ZX can be use effectively for measuring the working length of root canal after instrumentation with Crown-down pressureless technique regardless of the presence of electrolyte in root canal.

• Restorative Dentistry and Endodontics
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• v.46 no.1
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• pp.5.1-5.13
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• 2021

Objectives: The aim of the current study was to assess whether the amount of extruded debris differs for straight and severely curved root canals during retreatment using H-files, R-Endo, Reciproc and ProTaper Universal Retreatment (PTU-R) files. Additionally, the area of residual filling material was evaluated. Materials and Methods: Severely curved (n = 104) and straight (n = 104) root canals of maxillary molar teeth were prepared with WaveOne Primary file and obturated with gutta-percha and AH Plus sealer. Root canal filling materials were removed with one of the preparation techniques: group 1: H-file; group 2: R-Endo; group 3: Reciproc; group 4: PTU-R (n = 26). The amount of extruded material and the area of the residual filling material was measured. The data were analyzed with 2-way analysis of variance (ANOVA) and 1-way ANOVA at the 0.05 significance level. Results: Except for Reciproc group (p > 0.05), PTU-R, R-Endo, and H-file systems extruded significantly more debris in severely curved canals (p < 0.05). Each file system caused more residual filling material in severely curved canals than in straight ones (p < 0.05). Conclusions: All instruments used in this study caused apical debris extrusion. Root canal curvature had an effect on extruded debris, except for Reciproc system. Clinicians should be aware that the difficult morphology of the severely curved root canals is a factor increasing the amount of extruded debris during the retreatment procedure.

• Restorative Dentistry and Endodontics
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• v.8 no.1
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• pp.77-87
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• 1982

The purpose of this study is to estimate the reaction of rat subcutaneous tissues following exposure to the various concentrations of formocresol (100, 50, 20%), eugenol (100, 75, 50%), and sodium hypochlorite. (5, 3.5, 0.5%) The results were as follows: 1. As the concentration of formocresol was decreased, the inflammatory reaction was decreased conspicuously. 2. The inflammatory reaction of 100% eugenol was appeared to be similar to that of 75% eugenol. The inflammatory reaction of 50% eugenol was decreased conspicuously. 3. No significant differences were found in inflammatory response between 3.5% and 5% sodium hypochlorite. 4. The inflammatory reaction of 0.5% sodium hypochlorite was mild and appeared to be similar to that of saline solution in 7 days.

• Journal of the Korea Furniture Society
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• v.19 no.2
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• pp.124-129
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• 2008

Moisture content of Larix kapempferi was maintained at 28% after air drying. 5% CCFZ solution penetration depth was observed through longitudinal tracheid and axial resin canal. Penetration depth was increased significantly from heartwood to sapwood and the penetration depth was found 1.3 times higher for sapwood measured at 15.0 second of penetration. On the other hand, liquid flow in sapwood and heartwood involved most liquid first entering the resin canals. Overall resin canal conducted 1.4 times more than tracheid. Latewood was found more permeable than in earlywood. At the beginning of penetration, the speed was high and then decreased in the course of time.

• Journal of Chest Surgery
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• v.24 no.5
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• pp.475-479
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• 1991

Tetralogy of Fallot associated with atrioventricular canal defect is rare congenital anomaly. Because of complexity of the surgical corrections of two associated anomalies, the mortality of surgery has been high. We have experienced a case of the tetralogy of Fallot with atrioventricular canal defect in a 9-year-old boy of Down`s syndrome, and the anomalies were totally corrected with good result. Single Dacron patch was placed to close the ventricular septal defect and the pericardial patch for atrial septal defect. The right ventricular outflow tract was widened by infundibulectomy and pulmonary valvulotomy followed by Goretex patch in right ventricular outflow tract.

• Journal of Chest Surgery
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• v.17 no.2
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• pp.171-176
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• 1984

Successful correction of the partial form of atrioventricular[AV] canal is now readily achievable. The most challenging technical features of this anomaly are the associated mitral valvular deformity and the frequent inability to obtain mitral competence. Residual mitral incompetence after repair of mitral cleft figures importantly in the causes of early and late failure. So, accurate and complete repair of the mitral valve cleft might be important. Determination of residual severe mitral regurgitation after repair is desirable to permit mitral valve replacement at the time. We have experienced one case of severe mitral regurgitation which was occurred 6 months after repair of partial form of A-V canal [ASD primum] in 22 years old virgin. Pre-op. left ventriculogram revealed severe mitral regurgitation in this patient. We preferred to perform mitral valve replacement with St. Jude valve in this patient at March 1984. Post-op. course was uneventful to now for 5 months and we report this case, review and discuss the literatures.

• Restorative Dentistry and Endodontics
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• v.16 no.1
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• pp.181-189
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• 1991

The purpose of this study was to evaluate the effect of apical seal produced by ultrasonic instrumentation. 120 extracted, permanent single rooted teeth were randomly divided into 6 groups of 20 teeth and root canals were enlarged & obturated according to Table I. After canal obturation, the obturated teeth were immersed in 2.5 % Methylene blue for 72 hrs. at $37^{\circ}C$ incubator and longitudinally sectioned. The apical sealing ability was evaluated by measuring the degree of dye penetration into the canal. The results were as follows: 1. All groups showed varying depth of dye penetration. 2. There were no significant differences between Group I and N, Group II and V, Group III and VI. (P>0.05) 3. Regardless of obturation method, there were no significant differences between hand instrumented group and ultrasonic instrumented group.(P>0.05).

• Restorative Dentistry and Endodontics
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• v.43 no.3
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• pp.35.1-35.7
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• 2018

The aim of this article was to showcase the endodontic management of a maxillary first molar with an unusual crown and root anatomy. Clinical diagnosis of the roots and root canal configuration was confirmed by a cone-beam computed tomography (CBCT) and the detection of the canals was made using a dental operating microscope. CBCT images revealed the presence of 5 roots with Vertucci type I canal configuration in all, except, in the middle root which had 2 canals with type IV configuration. The 6 canal orifices were clinically visualized under the dental operating microscope. Clinicians should familiarize themselves with the latest technologies to get additional information in endodontic practice in order to enhance the outcomes of endodontic therapy.