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Volume 6 (1987)
- Issue 2 Pages 127-
- Issue 1 Pages 1-
Volume 6, Issue 1
Displaying 1-12 of 12 articles from this issue
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Part 1 Surface Analysis of Corrosion ProductsKoichi MATSUDA, Yuji IBARAKI, Hideyuki SAKAI, Yutaka UNO, Hirokata SHI ...1987 Volume 6 Issue 1 Pages 1-8,119
Published: June 25, 1987
Released on J-STAGE: January 07, 2010
JOURNAL FREE ACCESSThe corrosion behavior of a commercial Ag-Pd-Cu-Au alloy in O.9% NaCl solution was investigated by an electrochemical technique, surface analysis of X-ray photoelectron spectroscopy and reflection electron diffraction.
No corrosion of the alloy examined was observed at negative potentials of -100mV or less.
In the potential region from 0 mV to +300mV, the alloy may be oxidized to form surface films of AgCl, AgO, Cu2O, CuO, Cu(OH)Cl, CuO and CuCl2 on the basis of the equilibrium potential for this system.
Pd in the alloy was oxidized to form PdO2 at +400mV and at +500mV. AgCl and Cu(OH)2 were found on the sample surface anodized at +400mV and +500mV. The amount of AgCl was greater than that of Cu(OH)2.View full abstractDownload PDF (1191K) -
Hiroshi SHIMOMURA1987 Volume 6 Issue 1 Pages 9-27,119
Published: June 25, 1987
Released on J-STAGE: April 21, 2009
JOURNAL FREE ACCESSThe characteristics of the method of curing resin using visible light was examined, photochemically.
Commercially available light curing units emitted much unnecessary light, predominantly in a long wavelength range. The internal hardness of cured resins increased with argon ion laser output along with deep hardness, but the maximum hardness was not always increased. The degree of polymerization of the commercially available composite resins measured using a laser Raman spectrophotometer was about 55 -70%, which indicated that there is ample room for improvement. The degree of polymerization of bonding agents in dentinal tubule determined by laser Raman microspectroscopy was about 80-85%.View full abstractDownload PDF (730K) -
Kazuo ITOH, Sadao WAKUMOTO1987 Volume 6 Issue 1 Pages 28-31,120
Published: June 25, 1987
Released on J-STAGE: April 21, 2009
JOURNAL FREE ACCESSThe effect of momentary pretreatment by 35% HEMA solution on the adaptation between dentin and resin material was investigated by measuring wall-to-wall polymerization contraction in a cylindrical dentin cavity.
Five marketed bonding agents tested in this study exhibited improved marginal seal when the dentin cavity wall was pretreated by 35% HEMA for a few seconds with the exception of Pyrofi1 Light Bond. It is concluded that the dentin cavity wall should be treated by HEMA prior to the application of a marketed bonding agent.View full abstractDownload PDF (738K) -
Hiromasa KATO1987 Volume 6 Issue 1 Pages 32-37,120
Published: June 25, 1987
Released on J-STAGE: April 21, 2009
JOURNAL FREE ACCESSThe relationship between the velocity of polymerization of light-cured resins and the wal1-to-wall contraction in a dentine cavity was studied. The final degree and the velocity of polymerization were determined by measuring the quantity of remaining carbon double bonds by infrared spectroscopy with respect to time. Diallylsulfonamide (DASA) as reducing agent in the experimental monomers increased both the velocity and the final degree of polymerization. Hydroquinone-monomethyl ether (MHQ) as inhibitor in the monomers decreased the velocity although its concentration did not affect the final degree. On the other hand, the wall-to-wall contraction increased with increasing content of DASA and with decreasing content of MHQ. From statistical analysis, it was found that the wa11-to-wall contraction was affected by the velocity of polymerization of composite resins, but was not affected by the final degree.View full abstractDownload PDF (337K) -
Triaminingsih P. SITI, Junpei SUGIZAKI, Kyoichi HORIE, Akitomi NAKAJIM ...1987 Volume 6 Issue 1 Pages 38-45,120
Published: June 25, 1987
Released on J-STAGE: April 21, 2009
JOURNAL FREE ACCESSThe bending characteristics of various brands of composite resins, which would represent the resistance against body fracture of resin restoration, were examined and the adequate indication of each material was detemined.
The bending strength of heavily filled composite was generally greater than that of macrofi11ed and MFR type composites, and were nearly equal to that of amalgam. However, these materials remarkably decreased in bending bond strength at the junction of subsequently added composite resin. Bubbleless mixing slightly improved the bending strength of the chemically cured composites as compared with spatula mixing.View full abstractDownload PDF (1747K) -
Masao IRIE, Hiroyuki NAKA1987 Volume 6 Issue 1 Pages 46-53,121
Published: June 25, 1987
Released on J-STAGE: April 21, 2009
JOURNAL FREE ACCESSThe marginal gap, shear bond strength to dentin and compressive strength for 6 g1ass ionomers and 2 composites were determined. A smaller marginal gap and greater bond strength were obtained at 24hours after filling than 30minutes after filling. At 24hours, these values for the glass ionomers were similar to those for the composites. Marginal gap decreased and either bonding or compressive strength was increased following the increase in the amount of powder added to the liquid. These differences were statistically significant.View full abstractDownload PDF (321K) -
Kunihiro HISATSUNE, Koichi UDOH, Masaharu NAKAGAWA, Katsuhiro YASUDA1987 Volume 6 Issue 1 Pages 54-63,121
Published: June 25, 1987
Released on J-STAGE: April 21, 2009
JOURNAL FREE ACCESSThe phase transformations in three different types of commercial dental alloys for porcelain bonding, a high-gold content alloy, alow-gold content alloy and a palladium-base alloy, were studied by measurement of electrical resistivity, X-ray diffraction and EPMA. Three distinguishable phase transformations and associated microstructural changes were observed in these alloys during the constant rate slow-cooling from 1000°C to room temperature. An ordered L12 type structure of (Pt0.67Pd0.33)3 Sn or Pt2PdSn phase was induced at the grain boundary in the high-gold content alloy. Phase separation was found in the low-gold alloy. An fct structure of (Pd0.67Ag0.33)3 (In0.6Sn0.4) based on Pd3In was formed as a blade-1ike precipitate within the grain interior of the palladium-base alloy.View full abstractDownload PDF (1729K) -
Akihiko SIMIZU, Takashi UI, Masahiro KAWAKAM1987 Volume 6 Issue 1 Pages 64-69,121
Published: June 25, 1987
Released on J-STAGE: April 21, 2009
JOURNAL FREE ACCESSThe effect of an adhesive resin cement (Panavia) lining in reducing micnoleakage of amalgam restorations with or without a glass ionomer base and fluoride treatment was exarnined. The prepared forty-eight cavities were assigned to 6 groups: amalgam restoration (Group I, control), amalgam restoration with Panavia lining (Group II), amalgam restoration with Lining Cement base (Group III), amalgam restoration with Lining Cement base+Panavia lining (Group IV), amalgam restoration with Lining Cementbase+Ag (NH3)2F treatment+Panavia (GrOup V), and amalgam restoration with Ag (NH3)2F+Lining Cement+ Panavia (GroupVI). After 100 thermal cycles, the teeth were immersed in 1% methylene blue. The degree of dye penetration was scored and assessed.
The use of Panavia as an adhesive liner (Group II) was effective in reducing microleakage of freshly placed amalgam restorations. The Panavia lining with a Lining Cement base (Group IV) was more effective, and the Panavia lining with the combination of Ag(NH3)2F treatment and a Lining Cement base (Group VI) was most effective.View full abstractDownload PDF (309K) -
Kazuhiko ENDO, Susumu HIRANO, Tadashi HIRASAWA1987 Volume 6 Issue 1 Pages 70-82,122
Published: June 25, 1987
Released on J-STAGE: April 21, 2009
JOURNAL FREE ACCESSThe effects of additives such as Cu, Mo, and Mn on the corrosion resistance of Ni-Cr alloy were investigated in Ringer's solution by the polarization resistance method.
The corrosion potential became noble and the polarization resistance increased with the addition of Cu or Mo. Anodic polarization measurements showed that these two elements retarded the anodic reaction and enhanced the passivation of Ni-Cr alloy.
Mn also reduced the corrosion rate of Ni-Cr alloy as well as Cu and Mo, although the inhibition mechanisms were different. Electrochemical measurements and microscopic observations showed that the presence of Mn did not contribute to the protectiveness of passive films but decreased the cathodic reaction rate of Ni-Cr alloys.
A good linear relationship was observed between average corrosion rate obtained from the weight loss measurement and average polarization conductance, and could be expressed as
icorr=25(mV)Ycorr.View full abstractDownload PDF (1825K) -
Tadao FUKUSHIMA, Takashi HORIBE1987 Volume 6 Issue 1 Pages 83-89,121
Published: June 25, 1987
Released on J-STAGE: April 21, 2009
JOURNAL FREE ACCESSFour kinds of succinoxy alkylene methacrylates with different lengths of alkylene groups were synthesized for use as bonding agents, and the bond strength of these monomers to polished dental alloys under dry and wet conditions was measured to investigate the effect of monomer structure on the bonding. There was no significant relationship between the monomer structure and the bond strength to precious alloys except for the Au-Ag-Pd alloy under dry conditions where the bond strength decreased with increase in the number of carbon atoms in the alkylene group. There was no significant relationship between the monomer structure and the bond strength to nonprecious alloys under dry conditions. However, the bond strength of the monomers with alkylene groups of 5 and 8 carbon atoms to the Ni-Cr alloy and that of those with short alkylene groups to the Co-Cr alloy, respectively, was higher under wet conditions.View full abstractDownload PDF (319K) -
(Part. 1) Application of Wire Explosion Spraying TechniqueYoshihiro TERADA, Takae HIMENO, Ryozo HIRAYASU1987 Volume 6 Issue 1 Pages 90-95,120
Published: June 25, 1987
Released on J-STAGE: April 21, 2009
JOURNAL FREE ACCESSChromatic characteristics were compared between the opaque porcelain fused matal substructures using a gold alloy and a nickel-chromium alloy with or without superficially sprayed with gold alloy.
From the stand point of the hiding efficiency for the metallic color of the substructure by opaque porcelain fusing, the gold alloy and the sprayed nickel-chromium alloy were superior to the nickel-chromium one as a metal for the porcelain-fused-to-metal crown. The likeness in color of the gold alloy and the sprayed one was also shown. As the conclusion, the application of wire explosion spraying technique which combines the advantages of the gold alloy and the nickel-chromium one appears to be quite useful for providing an excellent metal substructure for the porcelain-fused-to-metal crown.View full abstractDownload PDF (768K) -
Yosmo KOZONO1987 Volume 6 Issue 1 Pages 96-104
Published: June 25, 1987
Released on J-STAGE: January 07, 2010
JOURNAL FREE ACCESSThis is a review of the articles published in the Journal of the Japanese Society for Dental Materials and Devices (J J Dent Mat), written in Japanese with English abstract, and in the Dental Materials Journal (Dent Mater J), written in English, during the period from April, 1985 to March, 1986.View full abstractDownload PDF (442K)
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