巻号一覧
40 巻 (1996)
- 6 号 p. 1029-
- 5 号 p. 831-
- 4 号 p. 619-
- 3 号 p. 419-
- 2 号 p. 217-
- 1 号 p. 1-
前身誌
40 巻, 4 号
選択された号の論文の22件中1～22を表示しています
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川井 善之, 宮田 孝義1996 年 40 巻 4 号 p. 619-627
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリー“Surechigal Occlusion” is the occlusion, in which there is no occlusal contact in spite of remaining maxillary and mandibular teeth (Eichner classification C1). Antero-postero Surechigai Occlusion, in which remaining mandibular teeth contact the maxillary antero-free-end saddle and remaining maxillary teeth contact the mandibular postero-free-end saddle, is the most difficult case, and rotational change between maxillary and mandibular dentures in the saggital plane cannot be prevented.
This is a report on the antero-postero Surechigai Occlusion case followed up for 8 years after the denture insertion.抄録全体を表示PDF形式でダウンロード (14706K) -
西崎 宏, 畦崎 泰男, 江藤 隆徳, 豊田 浩行, 宅間 巌, 池田 直也, 井上 宏1996 年 40 巻 4 号 p. 628-634
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーThe masticatory function and the adaptation of patient's denture with Brånemark implant in the edentulous mandible was evaluated by using electromyography for 6 years. Electromyograms (EMG) of the bilateral posterior temporal and masseter muscles during gum chewing were recorded at insertion of the old full denture and at 1 month, 3 months, 6 months, 2 years and 6 years after insertion of implant denture. The interval, the duration and their integrated values of EMG bursts were measured.
The duration of EMG burst was shorter with the implant denture than with the old full denture and became about 300 msec from 3 months after insertion of the implant denture. The coefficient of variance (CV) of duration became stable from 3 or 6 months after insertion of the implant denture.
The EMG power coordination pattern was converted into a normal one representing the prominence of the working side masseter followed by the other three muscles after insertion of the implant denture.
The periotest values of the implant fixture were not significantly changed after insertion of the implant denture, and osseointegration has been maintained.
These results suggested that adaptation to the implant denture might require a longer period than that to the conventional denture.抄録全体を表示PDF形式でダウンロード (7383K) -
第2報床用レジンおよび人工歯の色調安定性と表面粗さ中本 匡美, 玉本 光弘, 浜田 泰三1996 年 40 巻 4 号 p. 635-639
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーIn this study, the effects of denture cleansers with berberine hydrochloride which showed antifungal activity in the literature (Part 1) on color stability and surface roughness of acrylic resin plate and artificial teeth were investigated.
The results were as follows:
1. At 24 weeks, the color changing vector of sample solution immersion was not significantly different from that of distilled water immersion of acrylic resin plate and three kinds of artificial teeth (two kinds of resin teeth and one of high wear resistance plastic teeth). One artificial tooth (high wear resistance plastic tooth) was not significantly different after 11-week immersion.
2. At 24 weeks, the surface roughness of sample solution immersion was not significantly different from that of distilled water immersion.抄録全体を表示PDF形式でダウンロード (877K) -
レイヤリング法について宮島 和臣1996 年 40 巻 4 号 p. 640-649
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーThree types of shade A system of dentin porcelain VITA for layering (2 D, 3 D, and 3.5 D) and 5 types of enamel porcelain (N, 1 E, 2 E, 3 E, and 4 E) in the layering method, in which more emphasis is put on cosmetic appearance, were evaluated. The thickness of the porcelain was varied and color tone in the abutment teeth color sample was changed, i.e., natural teeth (A 2, A 3, and A 3.5), 2 types of gold alloy and palladium alloy (Au and Pd) as casting metal core, and discolored teeth influenced the color tone of IPS EMPRESS crown. The conclusion were as follows:
1. Lightness difference When the ratio of the thickness of dentin and enamel samples was varied within the range of 1.5 mm (two-thickness samples), the lightness difference tended to decrease when thickness of the dentin sample was increased, while no interruption of color tone was observed.
2. Color difference
1) The smaller the shade number was, the higher the color difference was between Au and Pd samples and natural tooth color sample, and the color difference decreased when the dentin sample was thicker. Almost all two-thickness samples showed the value of 1.2 or more, i.e., within the criterion for color difference, and it was evaluated as “detectably different.”
2) In the color difference between discolored tooth sample and natural tooth color sample, the smaller the shade number was, the higher the color difference was. The color difference decreased as dentin sample became thicker. In all of the two-thickness samples, the value was 1.2 or more, thus falling within the criterion for color difference in the present study. Some of the two-thickness samples showed a color difference of 3.3 or more. Thus some samples were evaluated as “extremely different.”抄録全体を表示PDF形式でダウンロード (1962K) -
鈴木 政弘1996 年 40 巻 4 号 p. 650-659
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーThe purpose of this study was to investigate the relationship between condylar rotation and translation during habitual closing late phase in 20 patients with unilateral or bilateral reciprocal TMJ clicking and to compare it with the results obtained from 19 normal subjects to determine whether or not there is any relation with clinical findings.
The results were as follows:
1. The amount of condylar translation from 0.2 to 0 degree of rotation angle (designated 0.2 T value) was 1.44±1.25 mm. The amount was a larger value and had a wider range than that of normal subjects, which was 0.40±0.22mm.
2. Patients were divided into group A (7 patients) whose closing click occurred before 0.2 degree of rotation angle, group B (8 patients) whose closing click occurred after 0.2 degree, and group C (5 patients) whose closing click position was unclear. The 0.2 T value of groups A and C was 0.59±0.38 mm and 0.39± 0.19 mm respectively which was near to the normal subjects' average. However, the0.2 T value of group B was 1.44±1.25 mm, which was much larger than that of normal subjects.
3. Patients who had a small 0.2 T value tended to have good prognosis. It was clarified that the 0.2 T value could be an effective parameter for the prognosis of judgment.抄録全体を表示PDF形式でダウンロード (3919K) -
ITIインプラントについて樋口 大輔1996 年 40 巻 4 号 p. 660-671
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーThe purpose of this study was to investigate and compare the accuracy of working casts made from two methods (transfer-pin type and stone type). In addition, the cause of distortion of working casts was examined, impressions were made from an implanted metallic model of a simplified mandibular dentition, and working casts were measured using the three-dimensional measuring microscope.
The results were as follows:
1. The distortion of reference points, other than in the implanted area, for both the transfer-pin type and the stone type casts had a similar tendency.
2. In the implanted area, the reference points on the occlusal screw had a different tendency with relation to the amount of distortion and direction, the height and inclination of the abutments had different tendencies, and the stone type casts were more accurate than the transfer-pin type casts.
3. The existence of impression spacers and transfer-pins and the error of operation must be considered as probable causes of the differences of accuracy of the two types of casts.
4. The working casts made from the new method (using an implant head) were as accurate as the stone type casts.抄録全体を表示PDF形式でダウンロード (6134K) -
仮着と前処理による影響大森 実1996 年 40 巻 4 号 p. 672-681
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーThe differences due to the types of temporary cement and the period of temporary cementation as well as the effect of the pre-treatment during the adhesion on adhesive strength of the adhesive resin cement and dentin were evaluated by performing shearing adhesive strength test, by determining contact angle, and by scanning electron microscopy.
The results were as follows:
1. In Bistite Resin Cement and Imperva Dual, adhesive strength significantly increased more by etching treatment than by primer treatment. When Super Bond C & B was used, adhesive strength was 20 MPa or more regardless of the type of temporary cement and the period of temporary cementation. When Panavia 21 was used, adhesive strength increased significantly as the period of temporary cementation became longer except HY-BOND temporary cement.
2. On the surface of dentin after removal of temporary cement, except HY-BOND temporary cement, and cleaning, the contact angle of the surface of dentin significantly decreased. After etching treatment, the contact angle of the dentin surface increased in most of the cases as the period of temporary cementation became longer.
3. After the removal of temporary cement and cleaning, temporary cement remained on the surface of dentin, and the primer treatment of the dentin surface after removal of temporary cement and cleaning was not effective. However, by performing etching treatment on the dentin surface after the removal of temporary cement, except HY-BOND temporary cement and cleaning, smear plug was removed.抄録全体を表示PDF形式でダウンロード (4947K) -
上部構造による連結の力学的影響佐藤 孝弘, 草刈 玄, 宮川 修1996 年 40 巻 4 号 p. 682-694
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーThe effect of superstructure connection on bone stress around implants was investigated by three-dimensional finite element analysis. Three models (M 1-M 3) of a mandibular segment with a premolar and two distal implants were constructed from CT-scans. In M 1, tooth and implants were not connected ; in M 2, only implants were connected ; and in M 3, tooth and implants were connected.
In M 2, maximum equivalent stress was 60-65% of that in M 1 under mesial loads and 1-point buccal load. Under vertical loads, stress in M 2 and M 1 were similar and concentrated around the loaded implant. Under mesial loads, stress concentrated mesially and distally around each implant of M 1, but in M 2 and M 3, bone stress between implants was low. In M 3, under vertical and buccal loads, high stress concentrated mesial to the mesial implant. Under buccal loading of the tooth in M 3 and of the mesial implant in M 2, similar stress was calculated. Thus lateral guidance on a tooth connected to implants should be avoided.
Regardless of the model, stress in cortical bone was much higher than that in cancellous bone. Therefore, increasing implant diameter (i. e., contact area of cortical bone) may be more meaningful than increasing implant length (i. e., contact area of cancellous bone).
These results may be useful during treatment planning of implant placement and superstructure design.抄録全体を表示PDF形式でダウンロード (8054K) -
第1報消毒液浸漬が石膏硬化体の表面粗さと表面微細構造に及ぼす影響鬼塚 雅, 門川 明彦, 松下 容子, 自見 忠1996 年 40 巻 4 号 p. 695-701
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーTo investigate the influence of disinfectant solution on the surface of gypsum, 3% glutaraldehyde, 10% formaldehyde, and water were prepared and surface roughness was observed by SEM.
The results were as follows:
1. Immersion in any solution greatly damaged the surface of set gypsums, and surface roughness increased.2. It was suggested that immersion in solution for a considerably long time makes the surface rougher, because there was no significant difference between immersing in disinfectant solution and in water which wasused as a control.
3. SEM views showed that gypsum crystals which were grown on an acrylic plate were washed away, and gypsum crystal projections were created. Gypsum crystal on part of the surface of the set gypsum, which was immersed in glutaraldehyde and formaldehyde, was destroyed.抄録全体を表示PDF形式でダウンロード (7363K) -
武並 康史, 窪木 拓男, 東 義晴, 矢谷 博文, 山下 敦1996 年 40 巻 4 号 p. 702-709
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーChanges of interarticular-space distribution during jaw opening were quantified with corrected sagittal TMJ tomograms using a computer-aided image analysing system.
Ten healthy males and 2 healthy females held their jaw steady in open jaw positions. Nine separate sagittal tomograms were unilaterally obtained during closing on interincisal jigs of 0, 2, 4, 6, 8, 10, 15, and 20 mm dimensions. Normalized minimum joint space dimension in each opening position relative to the corresponding measurement during comfortable closure on the intercuspal position was determined in each subject.
Mean normalized minimum joint space dimension data showed that during opening, the anterior joint space dimension was reduced significantly (p<0.05) and during 15 mm opening, the dimension was reduced maximally. Furthermore, according to the increment of the jaw opening dimension, the position of the minimum joint space dimension was changed from anterosuperior to superior direction from the reference point of the condyle.
If it is assumed that joint space dimensional change is a good analogue of joint loading, it could be assumed that during jaw opening, there might be articular (surface to surface) compression between the condyle and articular eminence.抄録全体を表示PDF形式でダウンロード (3872K) -
沖山 誠司, 吉田 実, 山本 誠, 森井 まどか, 野首 孝祠1996 年 40 巻 4 号 p. 710-717
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーThe testing gumi-jelly, which has a standardized shape and physical properties, has been devised and used as a testing food to evaluate the masticatory efficiency of denture wearers. However, in dentulous people whose masticating abilities are generally greater than those of denture wearers, it seems necessary to evaluate masticatory efficiency by using testing foods with various hardnesses. Thus a new method using the four kinds of testing gumi-jelly with various hardnesses has been developed.
The purpose of this study was to investigate the influence of hardness of the testing gumi-jelly and the influence of occlusal contact factors (occlusal contact area, occlusal force, and total number of occlusal contact points) on masticatory efficiency.
Thirty dental students (24.1±2.0 years old) were selected as subjects who had intact dentition and no stomatognathic dysfunction. Occlusal contact factors were measured by a pressure sensitive sheet (Dental Prescale ® 50 H, R type).
The results were as follows:
1. It was shown that the surface area of masticated gumi-jelly tended to decrease and the interindividual variance of the masticatory efficiency tended to increase, as the hardness of the testing gumi-jelly increased.
2. The occlusal contact area, occlusal force, and total number of occlusal contact points significantly correlated (p<0.05) with the masticatory efficiency when the testing gumi-jelly within a certain range of hardness was used.抄録全体を表示PDF形式でダウンロード (1473K) -
装着2週間後の変化古谷 暢子, 池原 晃生, 野首 孝祠1996 年 40 巻 4 号 p. 718-724
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーTo understand the effect of habituation to removable prostheses on taste, the following experiments were conducted on 50 subjects indiscriminately, who have intact dentition. The gustatory responses of primary taste, which were shown by the threshold of sensation and the threshold of judgment, were examined by two sensory tests. Both tests were taken three times, without the experimental palatal plate, just after the insertion, and two weeks after insertion.
The first test was performed to change the direct cause of tasting difficulty due to the palatal plate covering the taste buds for two weeks.
The second test was performed to change indirect cause for two weeks. The indirect cause means that immediately upon wearing the palatal plate, the tongue space is infringed, and the rhythm of mastication is disordered. Thus the stimulus of taste had a tendency to prevent transmission to the taste buds, and taste was hard to make out.
Consequently, it was clarified that two weeks after the insertion of the palatal plate, tastes, which became hard to make out due to wearing the plate, recovered to those before wearing the plate. It is confirmed that two weeks after insertion of removable prostheses, habituation occurred, so taste disorders were ameliorated.抄録全体を表示PDF形式でダウンロード (1285K) -
マウスプロテクター装着が心肺機能に及ぼす影響西川 修弘1996 年 40 巻 4 号 p. 725-737
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーAn exercise tolerance test, with Bruce's protocol, was performed on eight normal subjects using a treadmill. The indexes of cardiopulmonary function, the endurance indexes and the results of a questionnaire given to the subjects were compared and examined. The conclusions were as follows:
The mean of all indexes of cardiopulmonary function increased with the passage of exercise time, but no striking difference was observed with regard to any of these conditions, whether the subjects wore no mouth-protector, a stock mouth-protector, or a custom-made mouth-protector.
The mean of the endurance indexes were almost the same for all conditions with no mouth-protector or with a mouth-protector of either stock or custom-made type.
When wearing a mouth-protector of the stock type, all subjects reported some difficulty in breathing during measurement. When wearing a custom-made mouth-protector, few experienced any breathing difficulty but the subjects suffered some discomfort from the presence of the appliance.
It would appear that the wearing of a mouth-protector on the upper jaw has hardly any effect on the cardiopulmonary function and endurance. Therefore the wearing of a mouth-protector may be effective in contact sports. The results of the questionnaire suggest that the mouth-protector should ideally be custommade.抄録全体を表示PDF形式でダウンロード (2362K) -
尾崎 康子, 草刈 玄, 宮川 修1996 年 40 巻 4 号 p. 738-748
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーThe purpose of this study was to investigate the influence of sprue size, casting method, and investment material on the porosity of titanium castings, approximating the form of dental crowns by density and X-ray transparent methods. The results were as follows:
1. The X-ray transparent method used in this study allowed the inspection of both occlusal and axial parts of the crown.
2. The X-ray investigation revealed a higher degree of porosity in the occlusal part than in the axial one. Furthermore, higher porosity was observed near the sprue.
3. When a 2-chambers type casting machine was used, porosity of crowns invested with high permeability investment material decreased with increase of sprue diameter. When an investment material of low permeability was used, crowns of defective form were obtained.
4. In the case of a 1-chamber type casting machine, number and size of crown porosities invested with high permeability investment material increased remarkably. Large porosities of irregular form were distributed throughout the casting. Whereas, in the case of low permeability investment materials, few porosities were detected using a thin sprue (1.5 mm).抄録全体を表示PDF形式でダウンロード (2332K) -
サーマルサイクルが及ぼす影響新井 大地1996 年 40 巻 4 号 p. 749-758
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーThe purpose of this study was to investigate the effect of thermal cycling on bond strength to denture base vesins and microleakage thereof into artificial teeth.
Four artificial teeth and three denture base resins (PMMA, PSF, and PC) were used in this study, and a cylindrical rod (5 mm in diameter and 5 mm in length) of each denture base material was prepared and then attached with a bonding agent to each artificial tooth previously polished with SiC # 600. The shear bond strength to and microleakage into each artificial tooth to various denture base materials after a specified number of thermal cycles were measured. The thermal cycle was adjusted to 0, 2, 000, 10, 000, and 20, 000.
The shear bond strength of polysulfone teeth to PSF and PC was greater than that to PMMA. The shear bond strength to and microleakage into resin teeth, hard resin teeth and polysulfone teeth to PSF and PC showed no change with the increase in the number of thermal cycles.
The results suggested that the application of a bonding agent to a denture base material such as polysulfone or polycarbonate was an effective procedure to increase the bond strength of resin, hard resin, and polysulfone teeth.抄録全体を表示PDF形式でダウンロード (3581K) -
大嶋 元彦, 新谷 明喜, 横塚 繁雄1996 年 40 巻 4 号 p. 759-766
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーIn order to clarify the properties of investments for titanium and the inner surface form change of a cast crown, a survey of roughness, hardness (Hv), compressive strength, setting expansion, and thermal expansion was made by using five kinds of titanium investment as well as by changing the condition of heating or not heating. Three kinds of investment except alumina having a very rough surface were selected, and cast crowns were made by changing the condition of using or not using the relief. The inner surface form change was comparativery investigated by a three-dimensional measurement system. The result were as follows:
1. As for setting expansion, the materials were divided into three types, i.e., the first was Selevest, Titavest, and Titanmold which remained fixed for two hours, the second was Titanium which indicated 0.2% at twenty minutes, and the last was Ceravest whose setting expansion increased from the beginning indicating 1.2% at ninety minutes.
2. As for thermal expansion, Selevest, Titavest, and Titanmold contracted by heating but Ceravest and Titanium expanded.
3. The indicated heating expansion rates were 0.2% for Selevest at 200°C, 0.6% for Titavest at 600°C, 0.5% for Ceravest and 0.5% for Titanium at normal temperature, and 0.3% for Titanmold at 800°C.抄録全体を表示PDF形式でダウンロード (1619K) -
第一報部分床義歯装着者の意識調査家入 美香, 松尾 浩一, 沖本 公繪, 寺田 善博1996 年 40 巻 4 号 p. 767-773
発行日: 1996/08/01
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 wearing a partial denture and taste. Denture and intraoral conditions of 44 partial denture wearers, 31 females and 13 males, aged 35 to 80 years, were examined by questionnaire on food, taste, and seasoning preferencesand taste perceptions.
The results were as follows:
1. Twenty-three subjects (group Y) showed the changes of food preferences as compared with those in their youth. However, these changes were not revealed in twenty subjects (group N). Nine of twenty-three thought that these changes may be due to wearing partial dentures.
2. Most of the upper dentures in group Y revealed the form similar to full denture. It was suggested that extensive covering of the soft palate by denture base influenced the taste.
3. The score of satisfaction and mastication of denture in group Y were significantly lower than that in group N. In addition, the degree of denture retention and fitting in group Y was less than that in group N. These may suggest that many denture problems were closely related with taste and/or food preference and perception.抄録全体を表示PDF形式でダウンロード (1429K) -
ボ一セレンラミネートベニアの色調遮断性について島田 和基, 宮島 和臣, 小見山 信, 中本 宏, 小峰 太, 高見澤 太郎, 大森 実, 桟 淑行, 五十嵐 孝義1996 年 40 巻 4 号 p. 774-781
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーIn crown restoration using porcelain laminate veneer discolored tooth, the hiding effect of the abutment sample serving as the background was evaluated by varying thickness of masking dentin and changing the cement at the time of adhesion. The conclusions were as follows:
1. When the thickness of masking was varied, the hiding effect was noted on all of the discolored abutment samples having a masking thickness of 0.3 mm or more.
2. When color was measured on two types of cement belonging to the system, the color difference (ΔE*ab) was 4.54 and 5.22 catalyst only and polymer cement respectively, showing a color difference. In particular, the change was higher in b* in both types of cement.
3. When opaque type cement was used even though masking thickness was 0.1 and 0.2 mm, the hiding effect was noted on the severely discolored abutment samples. When opaque type cement having a masking thickness of 0 mm was used, no hiding effect was found on the severely discolored abutment samples.抄録全体を表示PDF形式でダウンロード (1508K) -
プラークの付着, 歯肉の健康状態, 冠縁の位置からの検討齊藤 竜一1996 年 40 巻 4 号 p. 782-789
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーThe present study was undertaken to understand the relationship between the presence of periodontal associated bacteria on crowned and natural teeth and Plaque index, or Gingival index.
The presence of the bacteria on the periodontium of both types of teeth was evaluated based on reactivity with bacterium-specific monoclonal antibodies in immunoslot-blot assay. Both types of teeth were classified according to Loe and Silness's Plaque and Gingival indexes.
When the reactivity for monoclonal antibodies in plaque samples taken from crowned and natural teeth was compared with the Plaque index, significantly high reactivity was observed for plaque samples of crowned teeth with Plaque index 0 and 1. It was interesting that the reactivity forPorphyromonas gingivalis, the most predominant bacterium of periodontal pathogens, in plaque samples on crowned teeth with Plaque index 1 was significantly higher than that of natural teeth. The reactivity forPrevotella intermediaserotypes I and II was significantly higher in plaque samples of both types of teeth with Plaque index 1 than Plaque index 0.
The same tendency for reactivity in plaque samples of the crowned and natural teeth was also observed when both types of teeth were compared with the Gingival index.
Furthermore, the relationship between the reactivities of plaque samples from crowned teeth and their marginal positions was examined. Higher reactivity was observed when the crowns were fitted on the subgingival margin of the teeth than when they were fitted on the gingival or supragingival one.抄録全体を表示PDF形式でダウンロード (3580K) -
古谷 彰伸, 割田 研司, 川和 忠治, 大貫 佳鼓, 齊藤 誠, 宮崎 隆1996 年 40 巻 4 号 p. 790-795
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーThe purpose of this study was to investigate the surface texture and mechanical properties of Olympus Castable Ceramics (OCC) during crown fabrication.
The results were as follows:
1. Surface roughness of the specimens decreased and bending strength increased after mechanical polishing using emery paper, a silicone wheel, and diamond paste. However, there were no significant differences among the three kinds of polished specimens.
2. Surface gloss of the specimens increased significantly after mechanical polishing using emery paper, a silicone wheel, and diamond paste in that order.
3. The stained specimens showed a little more surface roughness than that of the polished specimens. Bending strength of the stained specimens was significantly less than that of the polished specimens and was slightly less than that of the untreated specimens. Surface gloss of the stained specimens was slightly less than that of the specimens polished with diamond paste.
4. Different conditions of surface preparation influenced surface roughness, surface gloss, and bending strength of the OCC specimens significantly.抄録全体を表示PDF形式でダウンロード (3996K) -
星野 浩之, 草刈 玄, 宮川 修1996 年 40 巻 4 号 p. 796-805
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーStandardized forms cast in titanium and 2 types (shoulder and chamfer) of titanium crowns were fabricated, and their fit was evaluated. Chamfer type Ag-Pd alloy crowns were also fabricated and their fit was compared with that of the titanium crowns. In addition, the castability was investigated using wedgeshaped casts of gold alloy and titanium. In the latter, 2 different spruing methods were used. The results obtained were considered as a baseline during the examination of titanium crowns. The titanium samples were fabricated using a casting machine (pressure difference type) and Al2O3/MgO based investment.
The results were as follows:
1. Accuracy of the standardized forms depended on heating conditions of the mold.
2. The fit of titanium crowns surpassed that of the Ag-Pd alloy crowns.
3. The fit of the shoulder type crowns was superior to that of the chamfer type crowns.
4. The spruing method influenced the accuracy of the edge in the titanium wedges.
The marginal fit of titanium crowns is influenced by titanium castability. The heating condition and spruing method should be chosen carefully and crown margins should be given an appropriate thickness to improve marginal fit.抄録全体を表示PDF形式でダウンロード (5626K) -
田中 みか子, 江尻 貞一, 河野 正司, 中島 正光, 小澤 英浩1996 年 40 巻 4 号 p. 806-811
発行日: 1996/08/01
公開日: 2010/08/10
ジャーナル フリーThe advanced age society will be coming up soon in our country. Postmenopausal osteoporosis is a major health issue and a matter of concern in the dental clinical field. It is important to find out its effect on the temporomandibular joint in relation to masticatory function and temporomandibular disorders of elderly people. In this study, an attempt was made to determine if estrogen deficiency affect the mandibular condyle.
Seventy-two adult female Fischer rats were used. Half of them were ovariectomized bilaterally (OVX) and the other half were subjected to sham surgery (Sham). Seven, 14, 30, and 60 days after surgery, 8 animals in each group were sacrificed and mandibles were carefully removed. The bone marrow area was assessed with binary image of soft X-ray photographs, and the bone mineral density (BMD) was measured by DEXA (Dual Energy X-ray Absorptiometry).
The binary imaged bone marrow area of the OVX group was significantly larger than that of the Sham group at 14, 30, and 60 days. Estrogen deficiency suppressed the reduction of the bone marrow area that occurs with aging in the rat mandibular condyle. However, no significant difference of BMD was found between the OVX and Sham groups, probably because cortical bone overshadowed the changes of trabecular bone.抄録全体を表示PDF形式でダウンロード (5296K)
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