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Satoshi Inoue, Bart Van Meerbeek, Yasuhiko Abe, Paul Lambrechts, Guido ...
2000 Volume 18 Issue 2 Pages
85-92
Published: August 15, 2000
Released on J-STAGE: June 07, 2011
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The purpose of this study was to evaluate the bonding effectiveness of a new ‘all-in-o e’ self-etching adhesive by TEM and by micro-tensile bond strength (MTBS) testing under various conditions (no vs. separate light-curing and composite vs. compomer), and to investigate the effect of an intermediate low-viscosity resin (LVR) on the MTBS to dentin.TEM revealed that the formation of a loosely organized 2-3 μm hybrid layer with collagen fibrils separated by resin-filled interfibrillar spaces. Resin-tag formation, ‘tubule wall hybridization’, ‘lateral tubule hybridization’ and a ‘shag-carpet’ appearance were observed, resembling the interfacial ultra-structure commonly presented with total-etch adhesives.With regard to MTBS, many specimens failed during preparation, even before they could be tested. Therefore, a survival rate was determined based on the percentage of specimens that survived during sample processing. When an intermediate LVR was additionally applied, the survival rate was significantly improved, though the MTBS remained in the same range. These results indicate that the bonding effectiveness of the ‘all-in-one’ adhesive might be affected by the application of the adhesive resin in a too thin layer. The more consistent results obtained with LVR might be due to an air-barrier effect that allows the adhesive resin to polymerize, and/ or an elastic shock-absorbing effect in partial compensation of polymerization shrinkage of the composite resin.
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Satoshi Inoue, Bart Van Meerbeek, Yasuhiko Abe, Yasuhiro Yoshida, Paul ...
2000 Volume 18 Issue 2 Pages
93-99
Published: August 15, 2000
Released on J-STAGE: June 07, 2011
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The purpose of this study was to investigate the effect of remaining dentin thickness (RDT) on the micro-tensile bond strength (MTBS) to dentin of a new resin-modified glass-ionomer cement for bonding composite resin. Composite resin was bonded to flat dentin surfaces from 14 extracted human teeth using Fuji BOND LC (GC) with or without a cavity conditioner, and then sectioned to thin slabs, trimmed into dumbbell shape with the area of the interface being approximately 1mm
2, and subjected to micro-tensile testing at a cross-head speed of 1mm/min. MTBS to dentin significantly improved when the cavity conditioner was used and RDT increased . When the conditioner was used, failures mainly occurred adhesively at the interface between the adhesive and composite resin .When no conditioner was used, no adhesive failures between the adhesive and composite resin occurred, but failures occurred mainly adhesively between dentin and the adhesive, or mixed adhesive-cohesively. These results indicate that removal of the smear layer improves the bond strength of the glass-ionomer adhesive to dentin; Its bonding effectiveness is also affected by the area of intertubular dentin available for micro-mechanical retention through hybrid-layer formation.
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Junpei Sugizaki, Toshimoto Yamada
2000 Volume 18 Issue 2 Pages
100-108
Published: August 15, 2000
Released on J-STAGE: June 07, 2011
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The purpose of this study was to observe the interfacial ultrastructure between the intact teeth or caries-affected dentin and resin with a newly designed one step total priming and bonding system, “Xeno CF” by using FE-SEM, and to determine the depth of fluoride-release into the underneath dentin at one week after bonding.
Tight adhesion was obtained between the intact teeth or caries-affected dentin and resin, and the hybrid layer about 1μm thick was observed at the resin-dentin interface.
Furthermore, the fluoride was detected up to 10μm depth under the resin-dentin interface.This system was expected to be clinically useful according to its simple procedure, tightadhesion to tooth tissue, and fluoride release.
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Especially on Finishing Technique
Mika Nemoto, Yoshikazu Kawamoto, Hiromitsu Shima, Kazushige Kawahara, ...
2000 Volume 18 Issue 2 Pages
109-118
Published: August 15, 2000
Released on J-STAGE: June 07, 2011
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The usage of dual-cured resin composite luting cement for adhesion of ceramics is becoming more popular in clinical work, but it is unknown the conditions after clinical removal of excess cement.
The purpose of this study was to evaluate the conditions around cement line after finishing with different rotary instrumentation.
The ceramics was applied to the bovine teeth surface with dual-cured resin cement. After light curing, super-fine diamond points (DT), 12-fluted carbide burs (CT), white points (WT, WM) and composite finishing disks were used to remove the cured resin. The conditions around cement line were examined with surface roughness, height of loss and SEM.The results suggested that the DT, CT, WT and WM removed excess cement entirely, but surface around the cement line was coarse. Using these instruments followed by application of disks, their surface became smooth but ditching was observed in the cement line.
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Ryunosuke Kazama, Kazuko Nakajo, Kazuyuki Ishikawa, Masayoshi Fukushim ...
2000 Volume 18 Issue 2 Pages
119-125
Published: August 15, 2000
Released on J-STAGE: June 07, 2011
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The purpose of this study was to examine the marginal and internal fit of all ceramic crowns fabricated by dental CAD/CAM “Cerec 2” system. This system was also compared with the laboratory heat-press technique “IPS Empress 2” system.“Cerec 2” crowns were made under two test conditions of spacer values; 1) 0μm group (n=10) and 2) 30μm group (n=10). On the other hand, “IPS Empress 2”crowns were made according to the manufac-uturers'instructions (n=10). All of test crowns were seated on the preparations with ad-hesive cement. The specimens were cut mesiodistally at the central portion. The thickness of resin cement layer at seven measuring points on cut surfaces was measured using a measuring microscope. In addition, when applying “Cerec 2” system, chair time from tooth preparation to cementation was measured.
The findings are as follows;
1. The overall mean thickness of cement layer of “Cerec 2” crowns was 222±57μm forthe Qum group and 193±32μm for the 30μm group. These values were significantly thickerthan that of “IPS Empress 2” crowns (125±37μm)(p<0.01). However, there was no significantdifference (p>0.01) in marginal fit between the 30μm group of “Cerec 2” crowns (100±58μm and 105±65μm) and “IPS Empress 2” crowns (90.5±63μm and 123±73μm).
2. Average chair time for “Cerec 2” chair-side restoration was about 90 minutes fromtooth preparation to cementation.
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Morphological Changes of Lased Surface
Atsushi Kameyama, Eiji Kawada, Masakazu Takizawa, Tetsuya Amagai, Tomo ...
2000 Volume 18 Issue 2 Pages
126-132
Published: August 15, 2000
Released on J-STAGE: June 07, 2011
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The purpose of this study was to evaluate the structural changes of Er: YAG laser-irradiated bovine dentin by different acid conditioner under scanning electron mi-croscope (SEM) observation. Extracted bovine dentins were irradiated Er: YAG laser (100mJ/pulse, 10pps) under water splay, acid treated, and observed under SEM. Unlased dentin without acid treatment was covered by smear layer and not observed the dentinal tubules. But a smear layer was not observed in lased dentin without acid treatment, and the surface was imbricate-patterned. When the lased dentin was acid-treated, the imbri-cate-pattern was milder, and the tendency was stronger when the demineralization effect of acid conditioner was stronger. Furthermore the treatment effect between peritubular dentin and intertubular dentin was different on the margin of lased spot. On the bottom of lased spot, unlased dentin-like structure was observed. These observations suggested that the structural character of acid-treated dentin following Er: YAG laser-irradiation was different in these parts.
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Influence of Airbrasion of Dentin Surface on Bond Strength to Bovine Dentin
Masashi Miyazaki, Naoshi Hirohata, Susumu Ando, Hideo Onose
2000 Volume 18 Issue 2 Pages
133-141
Published: August 15, 2000
Released on J-STAGE: June 07, 2011
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The improvement of bond strength of light-cured resins to tooth structure has driven the impact of adhesive dentistry in minimizing the loss of sound tooth structure and the clinical success of minimally invasive restoration allows dentists to use new cutting in-struments as an airbrasion. The purpose of this study was to examine the influence of cutting of dentin surface with airbrasion on dentin bond strengths of two-step bonding systems.
After treating the tooth surface according to manufacturer's instructions of commer-cially available 2-step bonding systems, restorative materials were bonded to dentin. Shear bond strength tests were carried out using a universal testing machine. From the results of this study, the bond strengths were affected by the methods of dentin cutting, and higher bond strength was obtained with #600 SiC abrasive than with the airbrasion, and this tendency was different among the materials tested.
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Ryuzo Kishikawa, Nanako Iwamoto, Norimichi Inai, Junji Tagami
2000 Volume 18 Issue 2 Pages
142-147
Published: August 15, 2000
Released on J-STAGE: June 07, 2011
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Dentin bonding systems were dramatically improved and conventional cavity form pro-posed by G. V. Black was not necessary for the adhesive restoration. The air abrasive system was improved as one of non-rotary devices for caries removal according to the current demand of conservative caries treatment. The purpose of this study was to evaluate the adhesive property of bonding systems to the dentin surface treated with an air abrasive system.
Two dentin bonding systems were used in this study. The tensile bond strengths to bovine dentin surface treated with an air abrasive system were measured and the dentin surfaces and the resin-dentin interface were evaluated using an SEM. The air abrasive system morphologically altered the dentin surface but did not influence the tensile bond strength to the dentin. The hybrid layer looked so irregular in the case of the air abrasive treat-ment. The mechanical damage of superficial dentin by the air abrasion should be disap-peared using phosphoric acid and self-etching primer.
It was concluded that the air abrasive system to remove the dentin substrate did not influence the dentin bond strength when the wet bonding technique or self-etching primer was applied to bond the resin composite to the dentin surface.
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Noboru Yasuda
2000 Volume 18 Issue 2 Pages
148-153
Published: August 15, 2000
Released on J-STAGE: June 07, 2011
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Junji Tagami, Yasushi Shimada, Yuji Kitasako, Masatoshi Nakajima, Toru ...
2000 Volume 18 Issue 2 Pages
154-159
Published: August 15, 2000
Released on J-STAGE: June 07, 2011
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New Concepts of Root Canal Treatment and Core Reconstruction
Shoji Kato
2000 Volume 18 Issue 2 Pages
160-169
Published: August 15, 2000
Released on J-STAGE: June 07, 2011
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Takashi Inoue, Shoichi Miyakoshi, Masaki Shimono
2000 Volume 18 Issue 2 Pages
170-176
Published: August 15, 2000
Released on J-STAGE: June 07, 2011
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Toru Sato
2000 Volume 18 Issue 2 Pages
177-182
Published: August 15, 2000
Released on J-STAGE: June 07, 2011
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