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第1報多目的用金合金の焼付強度
丸谷 善彦, 清野 豊, 芝 樺彦
1999 年 43 巻 5 号 p.
781-790
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
Multi-purpose gold alloys (Degunorm, Degudent LTG) were investigated as casting metal for conical double-crown telescopic prosthesis. Bond strength between porcelain and metal was compared to conventional ceramo-metal system. In addition, bond strength with some four treatments was also examined. The results were as follows:
1. Bond strength of multi-purpose gold alloy with its original low-fused porcelain was similar to those of conventional dental porcelain-fused metal.
2. Bond strength of Degunorm painted bonding agent after sandblasting showed the highest value under all test conditions in this study.
3. According to SEM observation, body-opaque interface after firing was definite. However, bondingopaque interface was not distinguishable.
4. The values of Vickers hardness (Hv) for body, opaque and bonding porcelain were 712, 325 and 468respectively.
5. Particle size of opaque porcelain was approximately 50 pm, and was coarser than that of bonding porcelain.
6. Leucite was detected in all of porcelain powders before firing. However, the leucite peak of body powder drawn in the X-ray diffraction chart was not obviously steep because it was amorphous.
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境界の連続性を考慮した解析
本永 三千雄, 石橋 実, 笠原 紳, 木村 幸平
1999 年 43 巻 5 号 p.
791-796
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
The purpose of this study was to investigate the stress distribution of porcelain crowns in function, using three dimensional finite element method (3 D FEM) analysis.
Conventionally, it was regarded the complex crown-cement-abutment as a continuum unit in 3 D FEM analysis. However, these analyses were not applicable to fracture aspects in the actual situation. Therefore, in this study, analysis was carried out under the condition that the complex crown-cement-abutment was regarded as a non-continuum unit in 3 D FEM analysis.
The results were as follows:
1. As for the complex crown-cement-abutment as a non-continuum unit, 3 D FEM analysis of porcelain crowns showed better results than conventional method.
2. Distribution of high tensile stress was localized in the convex portion of the cervical proximal inner line of crowns.
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佐藤 敬, 坂下 勝啓, 照井 崇之, 村松 弘康, 永井 成美, 石橋 寛二
1999 年 43 巻 5 号 p.
797-801
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
It has been suggested that a carving wax pattern might affect the color of heat-pressed dentin core. The purpose of this study was to evaluate the influences of carving wax on color of dentin ingot before and after heat-pressing. Seven kinds of carving wax (Inlay wax medium red, Inlay wax medium green, Color wax for enamel, Crown wax, Inlay wax hard, THO wax, Paraffin wax) for wax pattern were used and the color change of dentin ingot (T 2 and A 1) before and after heat-pressing were analyzed based on CIELAB color system. Color wax for enamel and THO wax influenced the color of dentin ingot (T 2, A 1), and Inlay wax hard influenced the dentin ingot A 1 with color difference dE over 3.0. On the other hand, visible color difference dE over 3.0 was not indicated in the heat-pressed dentin ingots fabricated by Inlay wax medium red and Crown wax.
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苦瓜 明彦, 山内 六男, 松木 光洋, 李 吉寿, 長澤 亨
1999 年 43 巻 5 号 p.
802-808
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
The antibacterial activity of newly-developed adhesive resin cement and primer on oral bacteria was investigated. Three types of adhesive resin cements and primers, and glass-ionomer cement as a control were used in the experiment.
S. mutansATCC 25175,
S. sanguisATCC 10556,
S. mitisATCC 3339,
S. salivariusATCC 25975, and
B. gingivalisATCC 3327 were used as test strains. Antibacterial activity of the resin cement immediately after mixing, after setting and after immersion in artificial saliva for one week were tested. A pH and fluoride release from resin setting were measured, and elute from settings was also measured by high-performance liquid chromatography.
Most resin cements and primers showed antibacterial activity against the
Streptococci, but did not show antibacterial activity against the
Bacteroides. Primers and resin cement immediately after mixing showed greater antibacterial activity compared to the settings of resin after immersion of artificial saliva. A pH and fluoride release of settings of resin cement were not related to the antibacterial activity. HEMA, Mac-10, MDP and Bis-GMA were identified from settings and primers by high-performance liquid chromatography.
The results suggested that the antibacterial activity was produced by the monomer of resin cement and primer.
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支台間の傾斜の影響について
石浦 雄一
1999 年 43 巻 5 号 p.
809-820
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
The purpose of this study was to investigate the accuracy of working casts made from two types of model, aparallel type and an angled type. Athree-dimensional measuring microscope was used to measure reference points on the master model and working casts.
The master model was made from metal, and standard points A, B and C were located on the base of the master model. Reference points were provided on the occlusal surface and on the measuring jigs for implants.Impressions were taken using a custom tray and additional type silicone impression material, and working casts were made. Then the working casts were measured and compared to the master model.
The results were as follows:
1. In the implant area the distance between the two implants was greater than that of the master model for both types of working casts.
2. Clockwise rotation of the implants was observed in both types of working casts.
3. For the angled type working casts, reference points of the remaining teeth moved to a lower position.
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前後的傾斜の診断法の検討
村上 格, 大塚 昭彦, 梶井 正文, 浜野 徹, 川畑 直嗣, 長岡 英一
1999 年 43 巻 5 号 p.
821-829
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
In cases of mandibular distal-extension edentulous ridge, it is considered that the anteroposterior and buccolingual inclinations of the edentulous ridge affect the stress of the abutment teeth transmitted from the removable partial denture.
However, few studies have examined this effect, and ridge inclinations of these areas are usually assessed and diagnosed by visual examination of mounted diagnostic casts.
A shape analyzing system for the mandibular distal-extension edentulous area was developed using a semi-conductor laser, and this system was applied to three cases. In this system, the ridge contour was divided into small triangles and normal lines were drawn at the centers of gravity of the respective triangles. The ridge inclinations were evaluated on the angles between each normal line and the tentative plane of occlusion. The results were shown on a personal computer as the occlusal, lateral, and frontal views, and the distribution on the anteroposterior and buccolingual inclinations of the edentulous ridges was shown by a histogram.
It was considered that this system is more accurate for evaluating the ridge shape on the distribution and degrees of anteroposterior and buccolingual inclinations of the mandibular distal-extension edentulous ridges than visual examination.
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西田 圭, 小野 高裕, 野首 孝祠
1999 年 43 巻 5 号 p.
830-838
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
In function, the movement of removable partial denture in various directions is caused by biting force or masticatory force. For free-end saddle denture, these movements are known to have a bad influence on abutment teeth or residual ridges.
For denture retention and stability and for protecting supporting tissues, movement should be kept as small as possible.
In this study, by focusing on the artificial teeth arrangement procedure which minimizes denture movements in function, it was attempted to establish a method of measuring lower unilateral denture base movement under loading and of analyzing it as rotation with a three-dimensional 6-degree comparator.
The results were as follows: 1. An angle of denture base rotation on the horizontal plane (Yawing) tended to be smaller than that on the frontal plane (Rolling) and on the sagittal plane (Pitching). The loading position had little influence on the angle of Yawing. 2. Empirical equations, which express the angle of Rolling and Pitching, were obtained from the investigation of the relation between the denture base movement and the loading position in the frontal sections of the residual ridge. These results suggested that the position of artificial teeth on the residual ridge, which control the denture base movement, could be estimated by using these equations.
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切削法が表面性状に及ぼす影響
佐藤 吉則, 秋山 逸馬, 大山 哲生, 瀧本 博至, 中壼 一介, 中島 伸一郎, 太田 彰人, 永井 栄一, 大木 一三, 西山 實
1999 年 43 巻 5 号 p.
839-848
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
In this study, a dental CAD/CAM system using titanium in the dental clinic was investigated. This system consisted of a CAD to perform prostheses visualizing and CAM to perform the procedure. There are many reports on this system and studies on the CAD system. However, the fitness of prostheses in the dental clinic is important, and the accuracy of manufacturing by CAM must be investigated in detail.
High bio-compatibility titanium was very useful as the material for prostheses. Due to its characteristics, the casting method was difficult, and the CAD/CAM system using the cutting method as the manufacturing method was considered to be effective. In this study special attention was paid to the CAM system, and influence of milling methods on titanium surface was investigated. The results were as follows:
1. The difference in the milling method affected the external shape of the product.
2. The relationship of the cutting tool and shape of the titanium product and the difference in condition of milling affected the surface texture.
3. The configuration milling method necessary for high accuracy of manufacturing of the periphery was radial milling.
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中村 和夫, 小竹 雅人, 水谷 紘, 植野 良子, 藍 稔
1999 年 43 巻 5 号 p.
849-856
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
It has been pointed out that properties of the magnetic keeper may change from original condition after casting. In this study, to evaluate the effect of the casting and the heat treatments for the casting alloy on the property of the keeper, hardness test and light microscopic observation were carried out.
Two kinds of keepers (HICOREX Slim, Hitachi Metals, Japan and Magfit 600, Aichi Steel, Japan) were investigated in this study. These keepers were cast on with gold-silver-palladium alloy (Castwell MC, GC, Japan). Then homogenization heat treatment and hardening heat treatment for gold-silver-palladium alloy were performed on the casting-on specimens. After casting-on and each heat treatment, hardness test and microscopic observation on the keepers were performed. Before these experiments, non-heated keepers were estimated as control.
The results for casting-on samples showed a decrease in hardness for both keepers. Furthermore, after each heat treatment, a decrease in hardness was found as compared to the control for both keepers (p<0.01, ANOVA).
In both keepers, microscopic findings showed that grains became larger than those of control and grain boundaries became distinguished.
The results showed that heat treatments for the casting alloy should be avoided because the properties of keepers were adversely affected.
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コ一ティング法による反応層の改善
森口 愛, 小正 裕, 柿本 和俊, 権田 悦通
1999 年 43 巻 5 号 p.
857-866
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
It was attempted to coat the refractory models by zirconia to improve a reactive layer of the pure titanium denture base cast using phosphate-bonded investment and to compare with a usual investing method.
When the coating refractory models were used, the small residual investment on the casting plate removing from the mold was observed.
The surface hardness of the castings prepared with TAIVEST was hardly different between the two samples. However, the surface hardness of the castings prepared with T-INVEST C & B was slightly greater control samples on the casting surface to a depth of about 30μm, but there was little difference between the samples for the depth.
In the coating samples, the microstructure of the surface of the castings showed almost no evident chill layer. The control samples had a chill layer and a columnar crystal layer extending from the surface toward the interior.
Use of the electron probe microanalyzer (EPMA) to determine distribution of various elements in the superficial layer of casting plates showed the reactive layer contained Si and P in control samples. In coating samples, it showed a small reactive layer contained impure elements though there was a high density of Zr of the surface layer of the castings.
The results are suggested that it is possible to improve a reactive layer of the surface of pure titanium denture base cast using phosphate-bonded investment by coating of the surface of the refractory models.
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森 宣昭, 高橋 裕, 清水 博史, 羽生 哲也
1999 年 43 巻 5 号 p.
867-870
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
This study was conducted to investigate the transverse strength at the proportional limit of a heat-cured denture base resin relined with low stimulative direct denture reline materials. The relined specimens with three low stimulative and a conventional self-cured direct denture reline materials were tested with a three-point loading test after 1 day of water immersion. Direction of load on the specimens also was tested. As a result, all relined specimens had significantly lower transverse strength than bulk of a heat-cured denture base material. The transverse strength of specimens relined with low stimulative direct denture reline materials was significantly low as compared with specimens relined with a conventional self-cured type direct denture reline material. There was no significant difference among three low stimulative direct denture reline materials. The direction of load on the specimens did not have an effect on the transverse strength at the proportional limit.
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佐藤 雅之, 谷田部 優, 藍 稔, 若林 則幸, 中村 和夫
1999 年 43 巻 5 号 p.
871-876
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
The purpose of this study was to investigate the relation between clinical variables and patients' satisfaction with their new removable partial dentures. Fifty-three patients (35 females: mean age: 58.8 and 18 males: mean age: 60.5 years) completed the clinical questionnaire and underwent the psychometric measurements regarding various aspects of their new removable partial dentures using visual analogue scales (VAS). The clinical questionnaire concerned gender, age, denture arch (maxilla or mandible), and years of denture experience. VAS items were aesthetic, pain, comfort, stability, speaking, eating, and general satisfaction. Patients expressed less satisfaction with comfort, aesthetic, and speaking items of their dentures than stability and pain items, suggesting that the patients were likely to remain unsatisfied regarding these three items even though the dentists judged the dentures functioned well. Female patients expressed significantly less satisfaction with all VAS items of their dentures than males. The younger patients tended to express less satisfaction with the eating item of their dentures than the older patients.
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第2報舌運動, 下顎運動との関連
森川 葉子, 市川 哲雄, 北岡 直樹, 河野 文昭, 羽田 勝
1999 年 43 巻 5 号 p.
877-883
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
Anterior palatal form affects the speech and is one of the important factors for the fabrication of upper denture. Air pressure in the incisor region was measured to examine the influence of the anterior palatal form on speech in the previous report. In the present study, the palatogram and jaw position were measured during the utterance of Japanese/sa/, /si/, /ta/, and /ci/. Subjects used and the experimental denture were the same in the report.
The results were as follows:
1. Palatogram was influenced by alterations of anterior palatal form. The thicker the anterior palatal counter, the posterior construction for fricative or plosive in the palatogram positioned during the utterances of /sal, /si/ and /ci/. The influence of the anterior palatal form was not observed during the utterance of /ta/.
2. The alterations of anterior palatal affected significantly the mandibular position. No general tendency was observed regardless of subjects.
The tongue movements primarily compensated alterations of anterior palatal form. This experiment confirmed that adequate anterior palatal form, i.e., width and location of S-ridge and the location, is important for the /s/sound production.
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咬合挙上による影響
羽田 詩子, 山村 理, 吉田 健, 三村 真一, 中村 和敬, 村上 昌之, 谷川 倫則, 丸井 義仁, 藤井 輝久
1999 年 43 巻 5 号 p.
884-890
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
This study was carried out in order to find out whether a mandibular position in pronunciation was effective in determination of the vertical dimension.
Cases of lost vertical dimension have often been seen in prosthetic treatment.
It is significant that these cases obtained correct vertical dimension and some methods have been reported. The advantage of pronunciation is used clinically.
The subjects bites were raised to a level above the free-way space by the bite plates, and the mandibularposition in pronunciation was recorded and analyzed by Bio PAK System.
The difference between with and without bite plate were observed.
The mandibular position in pronunciation has intra-individual variations, the greatest distance was decreased by the bite plate, and the mandibular positions without the bite plate were kept.
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岡 孝典, 倉知 正和
1999 年 43 巻 5 号 p.
891-902
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
Psychological and social stresses characteristic of the present age have been reported to not only induce psychological and mental instabilities but also affect systemic and local physiological functions and various tissues.
However, it is still unclear if those stresses have a direct influence on the functions of the jaw. With an aim to clarify the mechanism by which psychological stress causes functional changes of the jaw, a video of a mystery story was shown, as a factor of psychological stresses, to 15 subjects with normal jaw functions. Then their emotional states were evaluated by 1/f fluctuation in EEG (α-wave) and scores of State-Trait Anxiety Inventry and the author's original emotion test. The changes of masticatory movement, as a representative for jaw functions, were investigated.
The results suggested that audio-visual stimulation from video might elicit mental and psychological stresses and lead to changes in the masticatory movement in each subject.
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山村 善治, 倉知 正和, 宇野 光乗, 岡 孝典
1999 年 43 巻 5 号 p.
903-907
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
In this study, the application of 1/f fluctuation in the diagnosis of temporomandibular function was investigated.
The subjects were five patients of temporomandibular disorders (the patient group), and five adult males with individual normal occlusion of the functional stomatognathic system were the controls (the control group). The following tooth-tapping were conducted for four minutes, recorded on sirognathographs.
Power spectrum densities obtained through the tapping interval times of between each a cycle were analyzed using the fast fouries transform analysis. And power spectrum densities were analyzed using the analysis of variance between the patient group and the control group.
As a result, a difference between the groups was found at the 1% levels, respectively.
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藤井 肇基
1999 年 43 巻 5 号 p.
908-917
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
The influence of horizontal changes in the mandibular position on facial and cervical skin surface temperature was investigated, and the results were as fllows:
1. The skin surface temperature generally rose according to horizontal changes in mandibular position, began to decrease gradually before removal of the appliance, and returned almost to the temperature before horizontal changes 30 minutes after removal of the appliance.
2. The EMG activity generally increased according to horizontal changes in mandibular position, began to decrease before removal of the appliance, returned almost to the EMG before horizontal changes 30 minutes after removal of the appliance.
3. The influence of horizontal changes in the mandibular position tended to be greater for the direction L or R than A.
4. There was a close positive correlation between the skin surface temperature and EMG activity at each mandibular position and at each point of measurement.
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吉松 正, 鳥巣 哲朗, 山邊 芳久, 野口 和子, 橋本 信行, 藤井 弘之
1999 年 43 巻 5 号 p.
918-922
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
Jaw muscle forces in horizontal isometric jaw movements with maximum voluntary efforts were evaluated in fifteen healthy male participants (mean age: 24.7 years) in the postures of sitting upright with headrest, without headrest and supine. Horizontal jaw muscle forces were registered with intraoral force transducer. Force data were analyzed with ANOVA statistically. The results were as follows:
1. The maximum horizontal forces depended on the directions of the jaw movements (posteriorly pull. mean±S.D.; 16.3±13.3kgf>posterolaterally pull: 11.0±6.0kgf≅aanterolaterally push: 10.7±6.0kgf≅a anteriorly push: 10.2±6.9kgf, p<0.0001). However, no significant effects were found between the postures.
2. It seems that the results will give us the fundamental data to assess the horizontal jaw function.
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小林 博, 村松 瑞人, 河野 正司
1999 年 43 巻 5 号 p.
923-928
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
When the relationship between the electromyography (EMG) and the stomatognathic function was investigated, there are various analytical methods. However, there are no satisfactory methods for clinical use, so amplitude density function analysis of the surface EMG was applied in the stomatognathic region. The chief object of the analysis was to discriminate the spontaneous discharge that was to be seen in the muscle of the patient with pain in the stomatognathic area. Known waveforms (rectangular, triangle, and sine curve), normal EMG and spontaneous discharge of the EMG in a patient were studied.
By this analysis, the difference of the known waveform was represented by the shape of the density function. It was found that the distribution of the amplitude is directly related to the waveform. As for spontaneous discharge, the discrimination standard for the amplitude density function analysis was made by the half width of the distribution. Spontaneous discharge has a sharp peak in the amplitude density function comparing to the normal EMG. In comparison to the value of the half width divided by the distribution range, the spontaneous discharges (0.080±0.010) were separated from the EMG of the voluntary activity (0.13± 0.021).
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可変形状モデルの応用
三浦 周, 服部 佳功, 渡辺 誠, 塚原 保夫
1999 年 43 巻 5 号 p.
929-939
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
This paper presents a two-step method, based on magnetic resonance (MR) images, for threedimensional reconstruction of osseous components of a temporomandibular joint (TMJ), the mandibular condyle and the fossa. In the first step, images were segmented in order to extract the bony outline (contour) by using a two-dimensional deformable model. An object in the model was extracted by deforming the initial contour located near the object of the image. In the second step, using the surface reconstructed from the extracted contour as the initial surface, a three-dimensional deformable model was applied in order to extract the surface of the object. These procedures were handled semi-automatically. Multi-section 1-mm-thick sagittal images of the right normal TMJ were obtained with a 1.5-T MR system and surface coils by using a FLASH-3 D sequence (TR=50ms, TE=11ms) from an asymptomatic volunteer (male, age 31 years). From these images, the bony surfaces of TMJ were extracted using the above-mentioned method. Even though the extracted surfaces were a little smaller than the surface traced by e xperienced dentists, they showed the normal, anatomical form of TMJ.
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大塚 英幸
1999 年 43 巻 5 号 p.
940-941
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
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吉田 光宏
1999 年 43 巻 5 号 p.
942-943
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
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野坂 庸子
1999 年 43 巻 5 号 p.
944-945
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
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小野田 利枝
1999 年 43 巻 5 号 p.
946-947
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
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古藤 美帆
1999 年 43 巻 5 号 p.
948-949
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
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安田 俊治
1999 年 43 巻 5 号 p.
950-951
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
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矢田 仁美
1999 年 43 巻 5 号 p.
952-953
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
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額田 和門
1999 年 43 巻 5 号 p.
954-955
発行日: 1999/10/10
公開日: 2010/08/10
ジャーナル
フリー
