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Volume 20 (2001)
- Issue 4 Pages 247-
- Issue 3 Pages 195-
- Issue 2 Pages 127-
- Issue 1 Pages 1-
Volume 20, Issue 2
Displaying 1-6 of 6 articles from this issue
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Glauco Fioranelli VIEIRA, Angela De CAROLI, Jane Cleide AMORIM, Edmir ...2001 Volume 20 Issue 2 Pages 127-134
Published: 2001
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe color of an object is a psychophysical phenomenon. Regarding its physical aspect, the amount of light reflected from the surface of an object is taken into consideration many times.
Two brands of porcelain were used to make 10 specimens that were submitted to the following treatments: glaze, grinding, polishing and overglaze. All samples were analyzed with or without saliva. The final color differences of the ceramic were evaluated using a spectrophotometer, and reflectance curves were obtained. Results showed that there were no differences between the brands of porcelain.
Saliva did not interfere with the color of the porcelain, but re-established the original one, after the grinding process had altered it. The polishing also contributed to re-established the original color. The overglaze altered the original color, with or without saliva.View full abstractDownload PDF (703K) -
Part 2 Mechanical Properties of Experimental Ag-Pd-Au-Cu Alloys Containing Sn or Ga for Ceramic-metal RestorationsShin-ichi GOTO, Akira NAKAI, Yukio MIYAGAWA, Hideo OGURA2001 Volume 20 Issue 2 Pages 135-147
Published: 2001
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSEighteen Ag-Pd-Au-Cu alloys, consisting of nine Ag-Pd-Au-Cu mother compositions (Pd: 20, 30 or 40%, Au: 20%, Cu: 10, 15 or 20%, Ag: balance) containing either 5% Sn or 5% Ga as an additive metal, were experimentally prepared. Tensile strength, proof stress, elongation, elastic modulus, and Vickers hardness of these alloys were evaluated to clarify the potential of these alloys for use as ceramic-metal restorations as well as the effects of the Pd and Cu contents on their mechanical properties.
The tensile strength, proof stress, elongation, elastic modulus and Vickers hardness of the 18 experimental alloys were in the range of 410.0-984.0MPa, 289.7-774.3MPa, 2.2-23.7%, 81.3-123.0GPa and 135.7-332.3HV1, respectively. Ten of the 18 experimental alloys can be used for ultra-low fusing ceramics based on their proof stress, elastic modulus, elongation and hardness. Between the Ga- and Sn-added alloys, differences in tensile strength, proof stress, elongation and hardness were found at several Ag-Pd-Au-Cu compositions.View full abstractDownload PDF (1413K) -
Part 1. Examination of Sterilization Effects on Resin PlateYuki NAGAMATSU, Kiyoshi TAJIMA, Hiroshi KAKIGAWA, Yoshio KOZONO2001 Volume 20 Issue 2 Pages 148-155
Published: 2001
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSBactericidal activities of electrolyzed strong and weak acid waters for acrylic denture base resin were evaluated in order to discuss the applicability of these waters for sterilization of denture base. Only 1-minute immersion in the electrolyzed strong or weak acid water could completely eliminate the attached bacteria, Staphylococcus aureus 209P, on the resin plate. When the resin was relined with tissue conditioner, 5-minute immersion or 1- to 2-minute ultrasonic cleaning reduced the number of the bacteria from 105/cm2 level to 101/cm2 and no surviving bacteria could be detected after 10-minute treatment. These findings suggest that both the electrolyzed strong and weak acid waters are well applicable to the disinfectant for acrylic denture base showing excellent bactericidal activities in a significantly shorter treatment as compared with the conventional denture cleaning.View full abstractDownload PDF (1244K) -
Hisao FUKUI, Wei YANG, Shirou YAMADA, Yoshimasa FUJISHIRO, Arimichi MO ...2001 Volume 20 Issue 2 Pages 156-163
Published: 2001
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSRecently, titanium-tantalum alloys have been studied as implant materials for dental and orthopedic surgery. However, titanium and tantalum are difficult to mix by common arc melting and induction melting, because of their high melting point and the marked difference between their densities (Ti: 1, 680°C, 4.5g/cm3, Ta: 2, 990°C, 16.6g/cm3). Thus, the Cold Crucible Levitation Melting (CCLM) method was chosen to produce a Ti-30wt% Ta binary alloy in the present study. The CCLM furnace, with 1kg capacity, consisted of a water-cooled crucible comprising oxygen-free high purity copper segments and coils wrapped around the crucible and connected to a frequency inverter power supply. A qualified ingot of 1.0kg of Ti-30wt% Ta alloy was obtained. The ingot was characterized from the surface quality, chemical composition distribution and microstructure, and finally the melting process was discussed.View full abstractDownload PDF (2788K) -
Recep ORBAK, Varol ÇANAKÇI, Adnan TEZEL2001 Volume 20 Issue 2 Pages 164-171
Published: 2001
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe purpose of this study was to examine the effect of an electro-ionizing toothbrush with stannous fluoride in the treatment of dentin hypersensitivity following periodontal surgery.
Thirty-two volunteers with dentin hypersensitivity were divided in two equal groups each using different methods: (Group I) stannous fluoride dentifrice and hyG Brnde ionizing brush without a battery and (Group II) stannous fluoride dentifrice and hyG Brnde ionizing brush with a battery. The volunteers brushed their teeth for 3 minutes twice a day for 12 weeks following one either of the test protocols.
Mechanical (No 23 dental explorer), chemical (lemon juice) and thermal (dental air-water syringe) tests were used for the evaluation of the degree of dentin hypersensitivity. A subjective assessment of the degree of hypersensitivity for each stimulus was recorded. The evaluations were repected at 4, 8 and 12 weeks after surgical treatment.
The second group showed significantly less sensitivity than the first group. The findings appear to suggest that the ionizing brush may be an effective adjunct for the treatment of dentin hypersensitivity in post-periodontal surgery.View full abstractDownload PDF (1335K) -
Neamat ABU-BAKR, Linlin HAN, Akira OKAMOTO, Masaaki IWAKU2001 Volume 20 Issue 2 Pages 172-180
Published: 2001
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe purpose of this study was to evaluate the effect of alcoholic and low pH soft drinks on the surface roughness of compomer restorative materials. There were five tested materials and four immersion media. Specimens were immersed in test solutions for a 10-day period at a temperature of 37°C. Measurement of the surface texture was carried out using a laser scanning microscope (a non-contact laser stylus tracing method). This was also used to produce the Laser Scanning Microscope Image (LSM Image). Specimens immersed in orange juice and whisky displayed higher values for Ra & Rz than specimens immersed in soft drinks and deionized water. LSM Image showed a difference between the control and the examined side, especially for specimens immersed in low pH soft drinks this could be due to the erosive effect of the media. Alcoholic and low pH soft drinks caused deterioration of the materials surface, which may lead to a clinically detectable rough and dull surface.View full abstractDownload PDF (3903K)
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