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Volume 51, Issue 1
Displaying 1-17 of 17 articles from this issue
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—Influence of the Design of Finishing Lines on Metal Framework—Mitsuo Sasaki1984 Volume 51 Issue 1 Pages 1-25
Published: March 31, 1984
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSObservations were made on three partial edentulous models regarding the strain in a typical mandibular denture framework having a free-end saddle type, which were constructed of epoxy resin and silicone rubber. Five strain gages were attached to the positions anterior and posterior to the finishing lines and the middle portion of the major connector.
The strain was measured at these positions when the saddles were vertically loaded at four points, one being at the first molar site and three being aligned bucco-lingually at the second molar site, with the weight being from 0 kg up to 6 kg. It was found that the greatest strain was observed at the major connector. On comparing with the other parts, the strain was the greatest at the position posterior to the finishing line of the loading site. The shape of the saggital cross section of the finishing line considerably affected the force distribution. A denture framework with a non-retention type finishing line decreased the amount of the strain in comparison with the butt joint type. This tendency was generally evident in the three mandibular edentulous models.View full abstractDownload PDF (5825K) -
Saburo Kurihara, Takayuki Kuroda, Takahito Miyasaka, Kikuo Noguchi, Sh ...1984 Volume 51 Issue 1 Pages 26-35
Published: March 31, 1984
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSTo clarify the morphological lento-facial changes after Obwegeser-Dal Pont osteotomy, 23 cases of mandibular prognathism were analysed by means of lateral cephalometrics.
The results were as follows;
1) A high correlation (significant at 1% level) could be found between the horizontal relapse of the upper and the lower incisor, as well as between the horizontal relapse of the mandibular body and the upper incisor.
2) No correlation was found between the skeletal feature (mandibular plane angle, A-B difference) of each case and the extent of relapse.
3) A relatively high correlation was found between the displacement by surgery and relapse (significant at 5 % level) as well as between the extent of the mandibular rotation by surgery and that of relapse.
It was suggested from these results that the compensatory tooth movement after surgical correction is thought to play an important role in occlusal stability.View full abstractDownload PDF (913K) -
Part 1. A Measuring Method of the Occlusal Wear of RestorationsKyoichi Horie1984 Volume 51 Issue 1 Pages 36-44
Published: March 31, 1984
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSA method for measuring the occlusal wear of the restorations was devised newly and its precision was examined.
The positive resin replicas of a specially designed metal prototype with a slope and an artificial ivory teeth before and after reducinng the occlusal portion were produced using the silicone impressions.
The distance between the given portion of the prototype and the positive replica was almost the same, showing a difference between the prototype and the postive replica immediately after porymerization or after 1 or 2-year storage within 1μm. The relative error of the positive replica was 0.29%.
On the other hand, the silicon-rubber negative replica made from the positive replicas of the artificial ivory teeth were longitudinally sectioned bucco-lingually at the same portion. The occlusal profile was then obtained from the negative replica. The difference between the original occlusal profile and the plofile after reducing was measured.
The degree of the precision of this method was thus appraised to be approximately ±2μm (standard deviation) . This would be a reliable method for measuring the occlusal wear of the restorations.View full abstractDownload PDF (2702K) -
Part 2. Clinical EvaluationKyoichi Horie1984 Volume 51 Issue 1 Pages 45-65
Published: March 31, 1984
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSResistance to the occlusal wear of the composite resins for posterior use was investigated by using the new measuring method described in the previous paper. Sixty-seven Class I molar cavities were restored with Clearfil Bond System-F (CF) as anterior resin, with Clearfil Posterior (CP), K-G Composite Resin (KG) and GC Microrest Jar Type (MJ) as posterior resin and with Shof u Spherical-D (SD) as amalgam.
The degree of the occlusal wear of the restorations was mainly estimated at 6-month intervals after the insertion up to the two-year period. The wear surface was also observed by the SEM images on the replicas.
The findings obtained were follows:
1. The amount of the occlusal wear of the various restorations was 2 μm/year with the SD, 4 μm/year with the MJ, 13 μm/year with the KG, 16 μm/year with the CP and 40 μm/year with the CF.
2. The MFR resorations were the severest, when they were in close occlusal contact.
3. The worn surface was the roughest with the CF, followed in order by KG, CP, MJ and SD.
4. Correlation between the cavity width and the amount of wear of the composite resins was not observed.
5. The restorations are generally considered to be subjected to the repeated abrading stress by the food fibril during the chewing process.View full abstractDownload PDF (17816K) -
—Effects of Heat Condition in Processing and Ultraviolet Light Irradiation after Processing—Hisashi Taniguchi1984 Volume 51 Issue 1 Pages 66-102
Published: March 31, 1984
Released on J-STAGE: December 08, 2010
JOURNAL FREE ACCESSThe physical and chemical stability of the intrinsic pigments for facial prosthesis was investigated in order to improve the color stability when using it.
In the present study, TH/Red I and TH/Blue of SILSKIN® as intrinsic pigments and DOW CORNING® MDX-4-4210 as base elastomer were selected. The effects of the curing temperature and time (75°C: 80-260 minutes, 125°C: 40-130 minutes) in processing and the ultraviolet light irradiation (0-1, 008 hours) after processing on these pigments were evaluated by measuring the weight of the pigments in the materials.
The findings were as follows:
1. With regard to the curing temperature, the weight of both pigments did not change at 75°C but decreased at 125°C. The greatest degree of the decrease was observed at over 100 minutes of curing time. The degree of the decrease of TH/Blue was greater than that of TH/Red I.
2. With regard to ultraviolet light irradiation after processing, the weight of the pigments decreased with the increase of the irradiation period. The degree of the decrease of TH/Red I was greater than that of TH/Blue.
3. The effect of ultraviolet light irradiation after processing varied with TH/Blue according to the curing temperature but this was not observed with TH/Red I.View full abstractDownload PDF (30323K) -
Tetsuya Ishida1984 Volume 51 Issue 1 Pages 103-123
Published: March 31, 1984
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSThe purpose of this research was to simulate the relationship between the masticatory muscular force and the mandibular shape using the shape optimization method, which was developed in the field of mechanical engineering. The two factors studied were as follows:
First: Whether or not there is a relationship between the masticatory muscular force and the mandibular shape. It was found that the optimum shape obtained by applying the masticatory muscular force with this method was similar to the actual mandibular shape. This suggests that there is a relationship between the muscular force and the bone shape.
Second: On the basis of the above-mentioned result, the factor between the variations in the force of the masticatory muscles and in the mandibular shape was studied. The results obtained were as follows:
Various shapes of the mandible were obtained by changing the application of the amount of force, direction and the site of the attachment of the masticatory muscles.View full abstractDownload PDF (2386K) -
Akihiko Noge1984 Volume 51 Issue 1 Pages 124-136
Published: March 31, 1984
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSUsually, the porcelain, resin and metal teeth are used as denture posteriors. However, few studies were reported on the occlusal wear of these posteriors.
This study was conducted to find the degree of attrition in these different kind of artificial teeth. The three kinds of pairs of the posteriors were: (1) metal to metal teeth pair, (2) metal to porcelain teeth pair and (3) metal to resin teeth pair, and the occlusal wear was studied under a 1-kg load by impact and sliding. The degree of attrition was measured in regard to the decrease of the vertical height caused by occlusion and of the volume.
Results obtained were as follows.
1. The characteristics were that in all pairs the occlusal wear in regard to the height occurred rapidly in the early stage and then progressed slowly.
2. In comparing the wear of volume in all kinds of artificial teeth, the metal teeth showed the least wear and the resin teeth the greatest wear.
3. The occlusal wear of the resin teeth paired with several metals was the greatest in the decrease of both the height and volume compared with other pairs.
4. The least wear in volume of these pairs of teeth was observed in the metal to metal teeth pair.View full abstractDownload PDF (2494K) -
—An Approach by Tissue Culture Method—Toshio Tsuchiya1984 Volume 51 Issue 1 Pages 137-156
Published: March 31, 1984
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSFor the purpose of clarifying the reaction of the sutursite stimulated by standardized and bodily expansion, the followingin vitroexperiments were performed using the parietal bones of the newborn Polish-Dutch rabbit.
Preliminary experiment: To learn about the site, length and conditions for the culture
Main experiment: 1. To develop a culture apparatus to expand the suture to the standardized width
2. To observe the tissue reaction after the expansion when applying this apparatus
Additional experiment: To examine a tetracycline labeling
The results were as follows:
1) It was necessary to maintain the width of the suture by some method for culturing the suture.
2) Under conditions where O2is 50%, it is appropriate to have at least 5 days for the culture period where the enzyme in the medium consists of horse serum and chick embryo extract.
3) An orthodontic rapid expansion screw was applied to the apparatus to give a standardized displacement to the suture, called the hanging technique.
4) The tension group, which expanded 200 μ in width with this apparatus, indicated the following on the 4 th-days.
1. Increase of fibroblasts
2. Tension of the fibres
3. Extensive appearance of an immature bone-like tissue
4. Possible calcification judging from the findings of tetracycline labeling and CMR method
5) It was strongly suggested that this experimental model could be applied to tooth movement, bone growth and calcification.View full abstractDownload PDF (21650K) -
—From a Complete Denture Case with Unilateral TMJ Defect—Toshio Hayashi1984 Volume 51 Issue 1 Pages 157-168
Published: March 31, 1984
Released on J-STAGE: October 08, 2010
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[in Japanese]1984 Volume 51 Issue 1 Pages 169
Published: March 31, 1984
Released on J-STAGE: October 08, 2010
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[in Japanese]1984 Volume 51 Issue 1 Pages 170
Published: March 31, 1984
Released on J-STAGE: October 08, 2010
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[in Japanese]1984 Volume 51 Issue 1 Pages 171
Published: March 31, 1984
Released on J-STAGE: October 08, 2010
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[in Japanese], [in Japanese]1984 Volume 51 Issue 1 Pages 172
Published: March 31, 1984
Released on J-STAGE: October 08, 2010
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[in Japanese], [in Japanese]1984 Volume 51 Issue 1 Pages 173
Published: March 31, 1984
Released on J-STAGE: October 08, 2010
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[in Japanese]1984 Volume 51 Issue 1 Pages 174
Published: March 31, 1984
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSDownload PDF (141K) -
1984 Volume 51 Issue 1 Pages 175-183
Published: March 31, 1984
Released on J-STAGE: October 08, 2010
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1984 Volume 51 Issue 1 Pages 187
Published: 1984
Released on J-STAGE: October 08, 2010
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