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Masahiro ONO, Toru NIKAIDO, Masaomi IKEDA, Susumu IMAI, Nobuhiro HANAD ...
2007 年 26 巻 5 号 p.
613-622
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
The surface properties of three different resin composite materials which influence
Streptococcus mutans biofilm formation were evaluated using an artificial mouth system (AMS). Specimens were prepared from Clearfil AP-X, Grandio, and Reactmer Paste, and each material was divided into two groups: (1) surface was ground with 800-grit silicon paper (SiC#800); or (2) surface was polished with up to 1-μm diamond paste (DP1 μm). Biofilms were grown on the surface of each specimen for 20 hours, and then subjected to vortex agitation followed by measurement of retained biofilms. Surfaces with retained biofilms were also inspected by SEM. Significant differences were detected in surface roughness (Ra) between the two polishing conditions for all materials. The quantity of retained biofilm was significantly less (p<0.05) on Clearfil AP-X DP 1 μm than on Clearfil AP-X SiC#800. With Reactmer Paste, their surfaces registered the lowest amount of retained biofilm—but there were no significant differences between the two polishing conditions. In conclusion, polishing did not render all resin composites equally resistant to biofilm formation.
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Takashi NAKAMURA, Hisataka NISHIDA, Tohru SEKINO, Masahiro NAWA, Kazum ...
2007 年 26 巻 5 号 p.
623-627
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
The aim of this study was to evaluate the electrophoretic deposition (EPD) behavior of ceria-stabilized zirconia/alumina (Ce-TZP/Al
2O
3) granulated powder. Two types of slurry with powder-to-solvent ratios of 10 wt% and 20 wt% were used. Zeta potential of the slurries was measured using a spectrometer at different pH levels. Then, EPD was performed to measure the weight of the deposited particles at varying pH levels and at two voltages (50 V and 100 V). The isoelectric point of Ce-TZP/Al
2O
3 mixed powder was approximately at pH 8.5. When EPD was performed, deposition of ceramic particles was typically observed in the range of pH 3 to pH 7, with the greatest deposition found at around pH 7. Moreover, the deposition of ceramic particles increased with increase in slurry concentration and voltage.
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Yohsuke TAIRA, Miyuki SAKAI, Lei YANG, Takashi SAWASE, Mitsuru ATSUTA
2007 年 26 巻 5 号 p.
628-634
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
The purpose of the present study was to evaluate the bond strength between a fiber-reinforced composite (FRC) and six luting agents (Panavia F 2.0, Linkmax MC, Chemiace II, Multibond, Super-Bond C&B, and Fuji I). A prosthodontic resin composite material (RC-control) and a luting agent containing no functional monomer (MT) were used as controls. Shear bond strengths between alumina-blasted FRC and the luting agents were determined after 20,000 thermocycles. The FRC showed superior bond strength when compared with the RC-control. Highest bond strengths were achieved when FRC was bonded with Panavia F 2.0, Linkmax MC, Multibond, Super-Bond C&B, and MT, whereas Chemiace II trailed in the list of resin-based luting agents evaluated. Insufficient bonding was obtained with Fuji I. Results of the present study revealed that when fabricating restorations, the clinician should select an appropriate combination of resin composite material and luting agent so as to ensure the longevity of restorations.
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Takashi NAKATA, Megumi FUJITA, Futami NAGANO, Mamoru NODA, Hidehiko SA ...
2007 年 26 巻 5 号 p.
635-641
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
The purpose of this study was to examine the effect of a new thermal cycling method using PCR thermal cycler on the durability of two-step self-etching adhesive systems. Beam specimens for microtensile bond strength test were inserted into PCR tubes with distilled water. Thermal cycling (0, 1000, 2000, and 3000 cycles) was done with the PCR program at two different temperatures of 5 and 55°C for 30 seconds each using a PCR thermal cycler. After thermal cycling, specimens were subjected to microtensile bond strength test and fractured surfaces were observed by SEM. The bond strength of Imperva Fluoro Bond after 3000 times of thermal cycling was significantly decreased compared to those of less than 2000 cycles (p<0.05), whereas SI-R20401 showed no significant differences even after 3000 cycles (p>0.05). Results of this study revealed that bond strength was affected by the thermal stress introduced in this experimental model. Therefore, this new thermal cycling method is a potentially useful and accessible means to evaluate the durability of dentin adhesive systems.
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Kazuya YAMADA, Hiroyasu KOIZUMI, Yoshikazu KAWAMOTO, Yumi ISHIKAWA, Hi ...
2007 年 26 巻 5 号 p.
642-646
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
The purpose of this study was to evaluate the effects of acidic primers on adhesive bonding to sintered aluminum oxide (alumina). Alumina disks were primed with one of the following materials: Acryl Bond, All Bond 2 Primer B, Alloy Primer, Estenia Opaque Primer, Eye Sight Opaque Primer, M. L. Primer, MR. Bond, and Super-Bond Liquid. Specimens were then bonded with an acrylic resin initiated with partially oxidized tri-
n-butylborane (TBBO), and bond strengths were determined. Unprimed specimen was employed as the control. Average bond strength before thermocycling ranged from 20.5 to 41.9 MPa, whereas post-thermocycling bond strength ranged from 0.0 to 40.0 MPa. Of the eight primers, Estenia Opaque Primer and Alloy Primer showed better adhesive performance than the other materials. It could thus be concluded that either Estenia Opaque Primer or Alloy Primer—which contained an adhesive monomer, 10-methacryloyloxydecyl dihydrogen phosphate (MDP)—was recommended for bonding alumina with TBBO-initiated resin.
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Kamolparn PUGDEE, Yasuko SHIBATA, Nobuyuki YAMAMICHI, Haruhiko TSUTSUM ...
2007 年 26 巻 5 号 p.
647-655
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
Fibronectin (FN) can be immobilized directly on titanium surfaces using tresyl chloride activation technique. The key advantage of tresyl chloride activation technique lies in its simplicity. In this study, we examined the cell attachment and gene expression of MC3T3-E1 cells on FN-immobilized titanium using GeneChip. Cells attached on FN-immobilized titanium at a higher rate than untreated titanium. FN altered the gene expression profile, whereby 62 genes were found to be up-regulated, while 56 genes were found to down-regulate to over twice the level on day 14. FN not only enhanced the expression levels of IBSP and OMD, but also decreased SULF1 mRNA level. Taken together, the immobilization of FN on tresylated titanium promoted early matrix mineralization and bone formation.
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Kozo UMEMOTO, Shigeaki KURATA, Kumiko MORISHITA, Toshio KAWASE
2007 年 26 巻 5 号 p.
656-658
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
To make a base polymer of a new soft resin material, a copolymer of 1,3-Bis(methacryloxypropyl)tetramethyl disiloxane (BMPMS) and methyl methacrylate monomer (MMA) was investigated. It was found that the compressive strength, bending strength and bending modulus value of the copolymer decreased with increase in BMPMS concentration. While, transverse deflection increased with increase in BMPMS concentration. As for the 50% inhibitory concentration value, it was about 0.8 mM for BMPMS.
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Futoshi KOMINE, Takayuki IWAI, Kazuhisa KOBAYASHI, Hideo MATSUMURA
2007 年 26 巻 5 号 p.
659-664
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
The present study evaluated the marginal and internal adaptation of single-tooth zirconium dioxide (ZrO
2) ceramic copings or crowns with three different finish line designs. Twenty-four steel dies were prepared for maxillary central incisor crowns with the following finish line designs: shoulder (S), rounded shoulder (RS), and chamfer (C) preparations. Twenty-four standardized ZrO
2 ceramic copings were manufactured with a CAD/CAM system (Cercon Smart Ceramics), and the crowns were finalized by veneering with a feldspathic ceramic. Measurements for marginal and internal adaptation were performed at two stages: the copings and the completed crowns. No significant differences were observed between the three groups in terms of marginal discrepancy median value: S, 73/69; RS, 61/60; C, 64/55 (μm). However, significant differences in internal adaptation were widely found among all groups: S, 117/111; RS, 72/75; C, 56/57 (μm). As for intra-group comparisons of marginal and internal adaptation values for all groups, the differences were not significant. It was found that the finish line design seemingly wielded no influence on marginal adaptation of single-tooth ZrO
2 ceramic copings and crowns. It was also observed that the marginal and internal adaptation values in the present study were all within the clinically acceptable range.
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Wei-Jen CHANG, Sheng-Yang LEE, Chen-Che WU, Che-Tong LIN, Yoshimitsu A ...
2007 年 26 巻 5 号 p.
665-671
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
Resonance frequency (RF) analysis technology was used to design a new dental implant stability detector. To calibrate and test the performance of this novel apparatus,
in vitro and
in vivo models, respectively, were used. The RF values of the test implants detected using our new device and a commercially available analogous device (Osstell) were compared. Further, implant stability status was also detected clinically using our device at 2, 4, 8, and 12 weeks after surgery. A high correlation was demonstrated between the values measured with the two devices (y=0.31x-12.45; R
2=0.98, p<0.05). In our clinical tests, an initial RF value above 10.0 kHz indicated that the implant was ready to accept functional loading, while values in the 4.0-10.0 kHz range reflected the need for further osseointegration. In conclusion, these results indicated that our new device might be useful in a clinical setting for evaluating the healing status of a placed implant.
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Zelal SEYFIOGLU POLAT, Ibrahim Halil TACIR, Sebnem ESKIMEZ, M. Yusuf & ...
2007 年 26 巻 5 号 p.
672-676
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
By means of a pull-out test, this study compared the retentive force of three fiber-reinforced resin composite posts and a zirconia post. These posts were cemented using two different dual-polymerizing adhesive resin luting agents.
Forty freshly extracted canines were selected for the study. All tooth root were endodontically treated and the post spaces prepared. The posts were luted using luting agents according to the manufacturers' guidelines. A tensile force was applied, and all data were collected and analyzed statistically. Glass fiber posts that were luted with Panavia F (Group 3) had the highest median load (3.610 N), while zirconia posts that were luted with RelyX ARC (Group 8) had the lowest median load (0.926 N). Among the different post systems that were luted with Rely X ARC, significant differences were observed in their median tensile loads (
p<0.047). When comparing between Panavia F and RelyX ARC of each post system, a significantly higher tensile load was seen with zirconia posts luted with Panavia F (Group 7) (
p<0.032).
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Masanori HASHIMOTO, Shinichi FUJITA, Masayuki KAGA, Yasutaka YAWAKA
2007 年 26 巻 5 号 p.
677-686
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
Recently, one-bottle resins adhesives have been developed to reduce the number of clinical steps of resin application. They are now widely used in clinical dental practice. However, little is known regarding the detailed mechanism of bond degradation. Therefore, this study evaluated the durability of one-bottle resin adhesives using long-term water storage testing.
Resin-dentin bonded specimens were prepared using five commercially available one-bottle resin adhesives. The specimens were sectioned perpendicular to the adhesive interface to produce beams and stored in distilled water for 24 hours (control), 100, 200, and 300 days. After the water storage, each beam was subjected to a microtensile bond test and then SEM fractography was performed on the fractured surface.
Compared to the bond strength at 24 hours after bonding (control), the bond strength of all tested adhesives were significantly decreased after 100 or more days in water. SEM fractography revealed a typical type of deterioration in the adhesive-composite interface that might cause a decline in bond strength after aging.
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Ma'an M. NAYIF, Masatoshi NAKAJIMA, Richard M. FOXTON, Junji TAGAMI
2007 年 26 巻 5 号 p.
687-693
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
The aim of this study was to evaluate the regional mechanical properties of flowable composites with different initiation systems under free and constrained conditions. Forty cavities fabricated in resin blocks with or without bonding treatment were bulk-filled with Estelite Flow Quick (EFQ) or Palfique Estelite LV (ELV), followed by light irradiation for 10 or 30 seconds. Each specimen was sliced to three slabs parallel to the long axis. The middle slab was serially sliced from top to bottom to harvest three sticks for ultimate tensile strength (UTS) measurement. The remaining slabs were polished for microhardness (KHN) measurement. The results indicated that the UTS and KHN of both flowable composites decreased toward the bottom of the cavity and increased with prolonged light irradiation time. At the upper cavity region, UTS values of the bonded groups were significantly lower than those of the unbonded groups, except for the 10-second light irradiation group of EFQ. As for KHN, the values did not change significantly for both flowable composites between the unbonded and bonded groups.
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André Poitevin, Jan De Munck, Kirsten Van Landuyt, Eduardo Cout ...
2007 年 26 巻 5 号 p.
694-699
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
The aim of this study was to investigate in how far the way the specimen is fixed to the testing device influences the micro-tensile bond strength of adhesives to dentin. Compared to a flat jig, a notched jig enables the specimen to be aligned easier and more accurately perpendicular to the interface, thereby concentrating better the tensile stress at the actual interface. A notched jig yielded a significantly higher bond strength and the graphs showed more uniform fracture curves. On the other hand, fixation of the specimen at their top and bottom guarantees a perfect perpendicular fixation to the interface, following the specimen's length-axis. The stress-time graphs revealed a completely different stress-distribution pattern. A failure closer to the dentin-composite interface was more often seen and the coefficient of variance was the lowest. Therefore, this completely newly designed top-bottom set-up produced the most reliable bond strength data.
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Makiha HIOKI, Akikazu SHIN-YA, Rizako NAKAHARA, Pekka K. VALLITTU, Yuj ...
2007 年 26 巻 5 号 p.
700-707
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
The objective of this study was to evaluate the influences of enamel shape and bracket base configuration on shear bond strength from a biomechanical point of view. To this end, shear bond test and stress analysis using finite element method (FEM) were performed. Results obtained from both tests were then comprehensively investigated. Maxillary incisors were prepared for plane specimens, while mandibular premolars were prepared for curvature specimens. Shear bond test was carried out with three different test conditions. Two finite element models of enamel shape and bracket base configuration were also created. An approximate mean load of 200 N was applied. Results revealed that the shear bond strength of plane model was higher than that of curvature model. In conclusion, the present study revealed that shear bond strength was significantly influenced by enamel shape and bracket base configuration, whereby a curvature configuration tended to have lower bond strength.
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Atsushi YAMAZAKI, Yasushi HIBINO, Muneaki HONDA, Yuko NAGASAWA, Yoshia ...
2007 年 26 巻 5 号 p.
708-712
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
This study examined the effect of ambient water on the shear strength of glass ionomer cements for luting. Disk specimens were fabricated from four commercially available glass ionomer cements with different setting modes. At one hour after the start of mixing, the specimens were stored at 37°C for 24 and 168 hours in dry condition or in deionized water. Shear strength was then determined using a punch tool. The shear strengths of both conventional cements were significantly greater for the specimens stored dry as compared to those kept in deionized water (p<0.05). Conversely, resin-modified cement specimens stored dry had significantly lower strength compared to the specimens kept in deionized water (p<0.05). This was because the ambient water surrounding the resin-modified glass ionomer cements helped increase the shear strength of the cements under the experimental conditions tested.
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Yusuke SHIMAKURA, Yasuhiro HOTTA, Akihiro FUJISHIMA, Jun KUNII, Takash ...
2007 年 26 巻 5 号 p.
713-721
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
To increase the bond strength of CAD/CAM-fabricated, leucite-reinforced glass ceramics with a resin cement, the effects of the following were investigated: surface modification by tribochemical (TBC) treatment, followed by combined application of a silane coupling agent and a functional monomer as a primer. Bond strength was evaluated by a shear bond test. It was found that a silane coupling agent was useful for all the surfaces, particularly for the TBC-treated surface. This was because of the presence of a silica layer on the modified surface. The combination of a silane coupling agent and a functional monomer on the TBC surface allowed marked improvement in bonding, whereby the bonding endured 20,000 cycles of thermal cycling. Therefore, TBC treatment in combination with a silane coupling agent and a functional monomer as a primer substantially increased the bond strength of CAD/CAM-fabricated glass ceramics with resin cement, if the treatment conditions were appropriate.
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Hao WANG, Yasushi SHIMADA, Junji TAGAMI
2007 年 26 巻 5 号 p.
722-727
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
The purpose of the present study was to evaluate the effect of fluoride on resin bonding to artificially carious enamel. Specimens from demineralized human enamel sections were prepared using two commercially available adhesives (Clearfil SE Bond, Kuraray; Single Bond, 3M) and a composite resin (Clearfil AP-X, Kuraray) according to manufacturers' instructions. They were then immersed in phosphate buffered saline solution with varied fluoride concentrations at 0, 0.1, 0.5, 1, and 10 ppm. After immersion in each solution for one, three, or seven days, microshear bond strength was measured. The bond strengths of both adhesive systems to artificially carious enamel significantly increased after immersion in fluoride-phosphate buffer solution. Based on the findings obtained, we thus proposed not to remove the white enamel lesions for bonding in the clinic. They might be preserved and treated using fluoride applications.
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Mika FURUCHI, Akiko OSHIMA, Yumi ISHIKAWA, Hiroyasu KOIZUMI, Naomi TAN ...
2007 年 26 巻 5 号 p.
728-732
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
The aim of this study was to evaluate
in vitro the shear bond strength to a gold alloy of RMGICs combined with three metal priming agents. Gold alloy was primed with one of the following materials: Alloy Primer, Metal Primer II, or Metaltite. Non-treated group was considered as the control. Specimens were bonded with one of the following luting agents: Super-Bond C&B, Vitremer Luting Cement, Fuji Lute, or Xeno Cem Plus. Shear bond strength was then determined. The bond strengths of resin-modified glass ionomer cements primed with the metal priming agents were greater than that of non-treated group, except for the Vitremer Luting Cement-Alloy Primer combination. It was thus concluded that the priming agents employed in this study were substantially effective in improving the bonding of resin-modified glass ionomer cements to gold alloy.
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Miho NAKAMURA, Hidekazu TAKAHASHI, Iwao HAYAKAWA
2007 年 26 巻 5 号 p.
733-738
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
The present study investigated the feasibility of a high short-rod fiber content in denture base resins using polymethylmethacrylate (PMMA) powder with a small particle diameter. The effects of fiber contents on mechanical properties of composite resins were studied.
A commercial denture base PMMA powder (AC; average particle size, 150 μm) and an industrial PMMA powder (MB; average particle size, 4 μm) were selected. Short-rod glass fibers were mixed with the two powders at a mass ratio of 0-50%. Flexural strengths and moduli of the mixtures were evaluated by a three-point bending test.
The flexural strength of AC composites did not change regardless of fiber content, while that of MB composites increased significantly at fiber contents exceeding 40%. The flexural moduli of AC and MB composites at fiber contents exceeding 20% were significantly greater than those of AC and MB resins without short-rod glass fibers, respectively.
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Seicho MAKIHIRA, Yuichi MINE, Eduardo KOSAKA, Hiroki NIKAWA
2007 年 26 巻 5 号 p.
739-745
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
The present study was a molecular analysis of the initial differentiation of osteoclast precursor RAW264.7 cells on titanium specimens. RAW264.7 cell line was cultured on titanium specimens of which the surfaces were finished by wet grinding with 2000-, 1200-, 600-, or 180-grit waterproof abrasive paper. Total RNA was extracted from cells cultured in the presence or absence of Receptor Activator of NF-κB Ligand (RANKL), prior to cDNA synthesis for real-time quantitative reverse transcriptase-polymerase chain reaction analysis. Titanium surfaces initially enhanced the expression of osteoclast differentiation markers including tartrate-resistant acid phosphatase and cathepsin K in RAW264.7 cells cultured with RANKL stimulation, in a roughness-dependent manner. The mRNA expressions of both RANKL receptor, RANK, and its adapter protein TNF receptor-associated factor 6 (TRAF6) increased when RAW264.7 cells were cultured on titanium specimens with roughened surfaces, as compared with that of control specimen with a polished surface. These results, taken together, suggested that titanium surface roughness facilitated osteoclast differentiation through the activation of the RANK-TRAF6 signaling network.
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Wan-Yu TSENG, Min-Huey CHEN, Hui-Hsin LU, Chii-Wann LIN, Tseng-Ting HS ...
2007 年 26 巻 5 号 p.
746-755
発行日: 2007年
公開日: 2009/02/06
ジャーナル
フリー
The purpose of this study was to investigate the tensile bond strength of composite inlays to human dentin with two different cavity preparation tools (bur
versus Er, Cr: YSGG laser) and with two different bonding procedures (total-etch: Variolink II
versus self-etch: Maxcem). The specimens were divided into four groups: bur-cut/Variolink II, bur-cut/Maxcem, laser-ablated/Variolink II, and laser-ablated/Maxcem. The following characteristics were then investigated: morphological change, dentin-resin cement interface, surface roughness, and tensile bond strength. Results demonstrated that the tensile bond strengths of the four groups were 19.11±5.88 MPa, 8.54±2.38 MPa, 13.72±3.43 MPa, and 12.11±3.71 MPa, respectively. We concluded that Variolink II provided higher tensile bond strength to composite inlays than Maxcem. On the other hand, the bond strength of Variolink II with dentin cavity prepared by Er, Cr: YSGG laser was statistically lower than that prepared by bur.
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