Nihon Hotetsu Shika Gakkai Zasshi
Online ISSN : 1883-177X
Print ISSN : 0389-5386
ISSN-L : 0389-5386
Volume 27, Issue 4
Displaying 1-20 of 20 articles from this issue
  • Marking on the Porcelain Surface
    Masaaki Yamada
    1983 Volume 27 Issue 4 Pages 653-666
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
    The occlusal equilibration is very important procedure in the prosthodontics, especially crown and bridge prosthesis and plate prosthesis. The suitable occlusion is not adjusted by this procedure, as the result it, the overload or decubital ulcer on a specified teeth, tissue and temporomandibular joint disfunction may be taken in some cases. So the method and material of occlusal equilibration are very important factors for correcting occlusion.
    There are many reports for the method of occlusal equilibration, but there are few studies for occlusal adjustment supply. Furthermore, it is considered that the marking material and surface roughness used in these reports are rarely associated with the practical dentistry.
    The different surfaces of porcelain plate generally used in dental clinic are elected for the specimen. Then it is examined thoroughly that the differences of occlusal adjustment supply and clinical experience have an effected on the discriminating ability, repeat marking, bleeding coefficient of occlusal adjustment supply. As the results of these studies, the author arrived at the following conclusions.
    1. Discriminating ability:
    1) Concerning the discriminating ability on the surface roughness of porcelain and clinical experience, the polyethylen-made occlusal adjustment supply is best, in the order of silk and paper are unsuitable.
    2) Regarding as it's ability on the surface roughness of porcelain, the rough surface is better than the smooth.
    3) As it's ability on the clinical experience, the silk and paper-made occlusal adjustment supply are overstimated beyond it's precision without the clinical experience. Especially, it has a remarkable tendency that the inexperienced group overstimates more than the experienced. On the contrary, the polyethylene-made is underestimated.
    2. Repeat making:
    1) Concerning the repeat marking on the surface roughness of porcelain and clinical experience, the silk-made occlusal adjustment supply is largest in frequency, in the order of the paper and polyethylene are on the decrease.
    2) About it's frequency on the surface roughness of the porcelain, the rough surface is larger in frequency than the smooth.
    3) Regarding as it's frequency on the clinical experience, especially the inexperienced group overstimates more.
    3. Bleeding and bleeding coefficient:
    1) As for the bleeding and bleeding coefficient on the surface roughness of porcelain and each condition, the polyethylene-made occlusal adjustment supply is little, in the order of the silk and paper gain in quantity.
    2) About the bleeding and bleeding coefficient on the surface roughness of porcelain, the smooth surface is little than the rough.
    3) Regarding the bleeding and bleeding coefficient on each condition, the paper-made occlusal adjustment supply at the dry condition is less than at the wet condition. The silk and polyethylene supply are almost same level without the condition.
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  • Kazuhiko Ogata, Yoshinobu Maeda, Masatoshi Okada, Shin'ichi Wakita, Go ...
    1983 Volume 27 Issue 4 Pages 667-669
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
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  • Sadayuki Yuhda, Taizo Hamada, Tadashi Komai
    1983 Volume 27 Issue 4 Pages 670-674
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
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  • Effect of Relief on Die
    Yasuko Shimizu, Toru Iwata, Sumio Tada, Shuhei Miyauchi, Tadayoshi Miy ...
    1983 Volume 27 Issue 4 Pages 675-682
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
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  • Effect of a Bite Plane
    Masaaki Kotani, Hiroshi Ozaki, Nagami Sumida, Shuhei Miyauchi, Takao M ...
    1983 Volume 27 Issue 4 Pages 683-688
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
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  • Masanobu Takakuwa, Fumihiko Watanabe, Yohji Yanase, Hiroaki Suzuki, Hi ...
    1983 Volume 27 Issue 4 Pages 689-698
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
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  • Part 1. Physical and Mechanical Evaluation on the surface of denture resin treated with Perma Cure System
    Tetsuya Habu, Yutaka Takahashi, Itsuro Yoshioka, Akihiko Inanaga, Koji ...
    1983 Volume 27 Issue 4 Pages 699-705
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
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  • Takuo Tanaka, Eriko Fujiyama, Hiroshi Shimizu, Mitsuru Atsuta
    1983 Volume 27 Issue 4 Pages 706-712
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
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  • Yoshihito Marui
    1983 Volume 27 Issue 4 Pages 713-730
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
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  • Yoshio Tabata
    1983 Volume 27 Issue 4 Pages 731-748
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
    Taking an impression is an important clinical step in prosthetic dentistry because it links the treatment work and model technique together. Since the fabrication of the prosthesis requires indirect techniques, there are many high quality, newly developed materials available. However, hydrocolloid impression is one which has been used for quite some time. Compared with the others, the hydrocolloidimpression material has several advantages such as hydrophilia, better flow, and no requirement of pressure or mixing. But there are some disadvantages that have been pointed out: dimensional instability, weak gel strength, and impartation of a rough surface to dental stone. Many efforts have been made to alter its undesirable properties, yet still some remain. By using 4 types of hydrocolloid impression materials in two group-a) Rubberloid heavy bodied and 5/16 small stick (VAN-R) and b) Politube reqular and 3/8 stick white (SURGIDENT) and 12 types of model stones (9 dental improved hard stone and 3 hard stone), the following parameters were investigated: (1) dimensional stability, (2) accuracy, (3) effect of tray design, (4) detail reproduction, (5) surface character of stone model, and (6) the effect of fixation. According to the results obtained, the following observations can be made:
    (1) The hydrocolloid impression material maintained in a supersonic humidifier (100% humidity) or in a wet box (85-90% humidity) had minimal weight change while those kept in the open room environment (50% humidity) or in water were unstable. But the dimensional stability of stone casts derived from the hydrocolloid impression of the original bridge die was poor under all condition used. This suggested that a short time interval between the impression work and stone pouring as well high humidity would give good results.
    (2) When different stone types having different setting expansion values were used, there was no correlation between the degree of deformation and setting expansion values. Therefore dimensional changes can not be explained solely by setting expansion of the stone.
    (3) Comparing the retention ability of hydrocolloid impression material with different tray forms, there were the same dimensional changes with both the rimlock type tray and that without the undercut. This suggests that there is no retentive effect in the horizontal vector. The retention due to vis or perforations was similiar. Therefore separation of the impression material from the tray after the impression work probably influences dimensional change.
    (4) Concerning the reproduction of detail, all the hydrocolloid impression materials gave a good reproduction of a 10μm wide line, but there were differences with different dental stone. The stone crystal granule size giving good reproducibility was 5μm, and that giving the worst was 20μm. This was determined by SEM observa tion. It was suggested that the use of a granule size over 20μm would make it difficult to reproduce a 20μm wide line. Comparing the stone surfaces made from either Coltex or hydrocolloid impression material, the surface made from the hydrocolloid impression material revealed larger growing crystal granules which may be due to the surface roughness or hardness of the impression.
    (5) Stones whose surface character may be affected by hydrocolloid impression material were Densite, Silkyrock, Velmix, Surstone, Tewe and Rapid stones, while those not easily affected were Mode-rock, Fuji-rock, Sunrock and New metal rock as well as New plastone and Hydro-gips. Clinically, the latter group seem to have less surface roughness.
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  • Perma Cure System
    Yoshio Tabata, Norimasa Numakura, Junji Nitanda, Nankyo Ryu, Eiyu So, ...
    1983 Volume 27 Issue 4 Pages 749-758
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
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  • Part 1. Simulation Models and Three Dimension Repositioner
    Tohru Hoshino, Hirohito Urume, Yukio Kubota, Kunio Izumita, Naotaka Ta ...
    1983 Volume 27 Issue 4 Pages 759-766
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
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  • Tadashi Onizuka, Ryuji Higashi, Tadashi Jimi, Shigehisa Fukuda
    1983 Volume 27 Issue 4 Pages 767-773
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
    In order to determine the clinical assessment of the polycarboxylate cements, some test were made on four commercially available polycarboxylate cements and one zinc phosphate cement as control.
    The findings are as follows:
    1. Tensile strength of the polycarboxylate cements obtained with the crown model was similar or stronger than that of zinc phosphate cement. Tensile strength with taper 1/10 crown model was significantly stronger than that with taper 2/10 crown model.
    2. In case of the shear strength at dentine-polycarboxylate interface on smooth surface was stronger than on rough surface, and the result showed that adhesion was due to chelate bond. While the shear strength at dentinecement interface obtained with polycarboxylate cements was variable, it was certainly superior to that obtained with zinc phosphate cement.
    3. The shear strength of polycarboxylate cements was more than twice that of zinc phosphate cement.
    4. The polycarboxylate cements were not irritant to dental pulp.
    5. The properties obtained with these test made the polycarboxylate cement the material of choice for cementing full crown restorations and bridge work on vital teeth.
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  • Part 1. Clinical Case and Stress Relief
    Naoyuki Shinohara, Yoshito Minesaki, Tadashi Onizuka, Koichi Fujii, Ka ...
    1983 Volume 27 Issue 4 Pages 774-779
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
    In addition to the transformation of soft palate substance defect in a functional moment, considering conformity, blockade and speech etc., the authors have thought it preferable that the prosthesis be fabricated with elastic material. For this reason, a silicone rubber material (MDX-4-4210, Dow Corning Corporation) has been clinically applied to soft palate substance defect, and examined concerning physical properties. To obtain the physical properties of this material, a stress relaxation was recorded after the specimens were subjected to strain. Taking into account the stress relaxation curve from the results in this study, an analysis of a mechanical three element model has been put into practice. According to the results of the analysis of the mechanical model, the effects of time, curing condition and water temperature on physical properties have been compared.
    It was found that this material is extremely stable, and not influenced by time, curing condition or water temperature. Also this material has approximated the action as an elastic material in an occlusal moment with negligible viscosity.
    Finally the authors report that the prognosis of two clinical applications has been favorable.
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  • Iwao Hayakawa, Motoyasu Imai, Yoshiyuki Tsuji, Satoshi Takeuchi, Yutak ...
    1983 Volume 27 Issue 4 Pages 780-783
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
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  • Katsumi Tsunematsu
    1983 Volume 27 Issue 4 Pages 784-801
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
    The influences of vertical (V-type) and horizontal (H-type) prematurities with approximately 115μm in thickness on the jaw closing muscles were electromyographically evaluated. EMGs were obtained of the posterior portion of the temporal and masseter muscles bilaterally during successive jaw tapping and chewing gum chewing. Recordings were made on just before, immediately after, and 2, 7 and 14 days after wearing the experimental prematurity.
    After wearing the prematurity, increased APSP and decreased AOSP with the day were observed in the Hgroup, while little fluctuant APSP and immediately decreased and then gradually increased AOSP were recognized in the V-group.
    Coefficient of variation (CV) of APSP proved higher after wearing the prematurity, although it reduced to the control level at 2 days and 7 days after wearng the prematurity in the H-and V-groups respectively.
    Regarding duration and integrated EMG activity, smaller values in the H-group and larger ones in the V-group were found after wearing the prematurity.
    CV-coordination of burst activity obtained in the prematurity-wearing side chewing showed balancing-Mm predominant pattern in the V-group, and working-Tp predominant pattern in the H-group.
    From above mentioned results, it became clear that the responses of the masticatory motor system to the prematurities differed with the type of given premature contact. Furthermore, an injuriousness of the prematurity has been inferred from the view point of a force regulating mechatnism of the masticatory motor system.
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  • Part 3. Morphological Studies of Temporomandibular Joint on Adult and Child
    Kenji Takashi, Masahiro Hayasaka, Yoshihiro Tanaka, Naoki Omiya, Yasuh ...
    1983 Volume 27 Issue 4 Pages 802-818
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
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  • Kazuhiko Ogata, Yoshinobu Maeda, Masatoshi Okada, Goro Nishigawa, Yosh ...
    1983 Volume 27 Issue 4 Pages 819-822
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
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  • Part II. Technological Properties of Investment Exclusirely for Soldering
    Yutaka Tomita, Kyotaro Hada, Toru Ishizuka, Masayuki Koizumi, Shinya N ...
    1983 Volume 27 Issue 4 Pages 823-832
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
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  • Through Masticatory Efficiency Measuring Device by Means of Sedimentation Method
    Saburo Tetsuka
    1983 Volume 27 Issue 4 Pages 833-847
    Published: August 01, 1983
    Released on J-STAGE: August 10, 2010
    JOURNAL FREE ACCESS
    The author, applying the sedimentation method generally used in physics and applied chemistry to the prosthetic field, has taken measurements of the particle-size distribution of masticated particles, and for the purpose of finding criterion for rating the mastication efficiency, has carried out a preliminary experiment, using watersoaked, uncooked rice as material and the single sedimentation tube method, on the effect of the length of the sedimentation tube and inner tube diameter. Then on the basis of the preliminary experiment, the author contrived a double sedimentation tube method and built a particlesize distribution measuring unit. This equipment was used to test the particle separation, sedimentation time of sifted particles, the effect of separation and the quantity of saliva, particle retrieval time and mastication.
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