All issues
Volume 6 (1987)
- Issue 2 Pages 127-
- Issue 1 Pages 1-
Volume 6, Issue 2
Displaying 1-10 of 10 articles from this issue
- |<
- <
- 1
- >
- >|
-
I. Effect on Smear LayerYoshiaki TANI, Hiroya KAWADA1987 Volume 6 Issue 2 Pages 127-134,223
Published: December 25, 1987
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSWe investigated the possibility of treating the smear layer by laser irradiation. The surface of the smear layer was irradiated with a laser, and the changes were observed under a scanning electron microscope. A Nd-YAG laser (Osada YAG Laser) and a CO2 gas laser (Mochida Medilaser-MIC 30) were used in defocus. The results showed that both lasers induced changes in the smear layer. Depending on the irradiation level, the smear layer on the intertubular dentin was satisfactorily treated, with the tubular orifices closed.
Next, we determined the penetration of 1% methylene blue from the dentin surface when irradiated by both lasers under various conditions. It was found that while the dye applied to a non-irradiated dentin surface penetrated deeply over the entire area, an irradiated surface blocked dye penetration. This finding was also observed at low energy densities of 25-50J/cm2, which is very interesting from the standpoint of preserving dental pulp.View full abstractDownload PDF (4850K) -
Hideo MATSUMURA, Mitsuo NAKAMURA, Nobuo NAKABAYASHI, Takuo TANAKA, Mit ...1987 Volume 6 Issue 2 Pages 135-139,223
Published: December 25, 1987
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSAdhesive behaviors of porcelain, quartz and alumina were investigated using a silane coupling agent and ferric chloride together with 4-META/MMA-TBB resin. Using 4-META/MMA-TBB resin, porcelain pretreated with silane and ferric chloride showed bond strength above 20MPa after 2, 000 thermal cycles. Silane primed quartz and alumina bonded with 4-META resin showed excellent adhesive durability. Silane coupling agent and 4-META seemed respectively to be effective for bonding the silicon derivative and the aluminum compound, which were the main components of the porcelain.View full abstractDownload PDF (991K) -
KOM GaugeMasao MORIKAWA, Yoshio KOZONO, Shizuo TOYODA, Ichiro HAYASHI1987 Volume 6 Issue 2 Pages 140-147,223
Published: December 25, 1987
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSAn improved caliper type of bite gauge, named KOM gauge, was devised. It is characterized by the three-point reference system including an additionally equipped reference arm to be placed on the forehead as a reference point. Compared with the two-reference system in the conventional caliper type gauges, the three-point reference system is much more advantageous for setting the device in place and stably supporting it during measurement.
The reproducibility of the record of the vertical dimension of occlusion was evaluated through the repeated measurements on the subjects having definite centric stop with their own natural dentition. Independently on the skill of the operator, KOM gauge reproduced the record significantly better than the conventional gauges tested. With the use of this improved gauge it is expected to minimize the risk of misestimating the vertical dimension of occlusion.View full abstractDownload PDF (2233K) -
Minoru KAWAGUCHI, Tadao FUKUSHIMA, Takashi HORIBE1987 Volume 6 Issue 2 Pages 148-155,224
Published: December 25, 1987
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSFive types of BisMPEPP monomers with different side chain lengths were prepared from a commercial BisMPEPP monomer mixture in order to investigate the structural effect on the mechanical and physical properties of their polymers. The mechanical properties (transverse strength, elastic modulus, compressive strength, and Knoop hardness) decreased with increasing the side chain lengths of BisMPEPP monomers, but the water sorption value increased. There were no significant differences between the diametral tensile strength of each polymer. BisGMA polymer showed higher values for elastic modulus (in dry conditions) and Knoop hardness (in dry and wet conditions) than BisMPEPP polymers. The decrease in the mechanical properties of BisGMA polymer in water was larger than those of the others. It was found that the mechanical and physical properties of these polymers largely depended on their structural nature, especially the segmental mobility of their side chains.View full abstractDownload PDF (1211K) -
Masao MORIKAWA, Yoshio KOZONO, Shizuo TOYODA, Ichiro HAYASHI1987 Volume 6 Issue 2 Pages 156-164,224
Published: December 25, 1987
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe magnetic characteristics of various magnetic systems utilizing a Sm-Co magnet were examined. The attractive force became significantly larger by pairing two magnets or housing the magnet with ferromagnetic yoke. As the gap between the magnet and keeper increased however, the attractive force was rapidly decreased, and when the gap exceeded 0.5mm, it became almost the same as those of the single magnet systems or unhoused magnets. Although the housing effect of the half-shallowed yoke was reduced by half when no gap existed, the attractive force with this yoke became larger than that of the full-size yoke when the gap was 0.2mm or more.
The magnetic systems composed of a pair of magnets or a magnet housed with the full-size yoke may be superior when the system components are closely arranged, while the use of the shallower yoke may be more favorable in retention and ease of clinical application, when a larger gap is inevitably introduced.View full abstractDownload PDF (2164K) -
Yoshiaki TANI, Hideaki GOTO, Kazuo IDA1987 Volume 6 Issue 2 Pages 165-174,225
Published: December 25, 1987
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSIn vitro wear of sixteen posterior composite resins was determined by the glass beads abrasion test. The wear was remarkably greater with the thick slurry than with the thin slurry. Microfilled posterior composites were higher wear-resistant than highly loaded and blended posterior composites. There is little difference in wear between submicrofilled resins and microfilled resins with the thick slurry. This suggests that the filler particle size is relatively important to wear resistance of the posterior composite material. There was a close parallel between the results of the glass beads abrasion test and clinical observations. There is no consistency among the wear measurements in the toothbrushing abrasion test.View full abstractDownload PDF (3318K) -
Osamu OKUNO, Naoyuki SHIBATA, Ishi MIURA1987 Volume 6 Issue 2 Pages 175-184,225
Published: December 25, 1987
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe porous 60wt% Zr-40wt% Ti alloys have been developed to fix a prosthesis to bone by tissue ingrowth. Mechanical properties and pore structures of the porous Zr-Ti alloys were investigated as dental implant materials. The porous Zr-Ti alloys might have suitable open pore size for bone ingrowth. The microstructures of the porous Zr-Ti alloys were acicular α. The compressive strength was much higher than that of cortical bone. The bending strength was approximately half of the compressive strength. The elastic modulus was almost in the same range as the elastic modulus of cortical bone. The fatigue tests of the porous Zr-Ti alloys show that it might satisfactorily endure repetitive biting force even in the molar region.View full abstractDownload PDF (4782K) -
Naoyuki SHIBATA, Osamu OKUNO1987 Volume 6 Issue 2 Pages 185-200,225
Published: December 25, 1987
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSPorous Zr-Ti alloys were developed as dental implant materials. They had good mechanical properties for clinical use. These implants were inserted into the femurs of rabbits and the subsequent bone ingrowth was studied. The bone tissue could grow into three kinds of porous Zr-Ti alloys prepared in this study. The specimens consisting of sintered 350-420 and 500-590μm size particles gave especially high bond strength with bone of about 27MPa after 4 week implantation. Porous Zr-Ti alloys showed excellent biocompatibility with bone. The reaction with soft tissues was also investigated.View full abstractDownload PDF (6510K) -
Junji TAGAMI, Hiroyasu HOSODA, Yoji IMAI, Eiichi MASUHARA1987 Volume 6 Issue 2 Pages 201-208,226
Published: December 25, 1987
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe effect of N-methacryloyl aminosalicylic acid (NMSA) on the tensile bond strength between resin materials and bovine dentin and also its desensitizing efficacy on hypersensitive dentin were investigated.
In case of a composite resin, significantly greater bond was obtained by a combined treatment with 10% citric acid containing 3% CuCl2 (10-3 solution) and NMSA-liner, than that of the control group treated by H3PO4 only. Bond strength of MMA/TBB system resin was also promoted by NMSA application. In the clinical evaluation, the application of NMSA-liner has relieved most cases of the dentin hypersensitivity immediately after even a simple coating. For obtaining the long term effect, the dentin surface should be treated at first by 10-3 solution, though the efficacy was eliminated after a few days in some cases. Accordingly, this material seems to be promising both in the field of conservative dentistry and adhesive dentistry.View full abstractDownload PDF (2239K) -
1987 Volume 6 Issue 2 Pages e1
Published: 1987
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDownload PDF (36K)
- |<
- <
- 1
- >
- >|