巻号一覧
27 巻 (2008)
- 6 号 p. 755-
- 5 号 p. 647-
- 4 号 p. 485-
- 3 号 p. 315-
- 2 号 p. 153-
- 1 号 p. 1-
27 巻, 6 号
選択された号の論文の15件中1～15を表示しています
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Original papers
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Emre OZEL, Yonca KORKMAZ, Nuray ATTAR, Erdem KARABULUT2008 年 27 巻 6 号 p. 755-764
発行日: 2008年
公開日: 2009/04/30
ジャーナル フリーThe purpose of this study was to investigate the influence of one-step polishing systems on the surface roughness of different flowable composites and a microhybrid composite. A total of 120 disks were fabricated and divided into six groups according to the different composite restorative materials tested (n=20). Each group was further divided into four subgroups according to the polishing system (n=5). For the control group, samples were left undisturbed after removal of Mylar strip. For the other three subgroups, samples were polished with PoGo, OptraPol, or Sof-Lex disks. Surface roughness was determined using a profilometer and observed under scanning electron microscope (SEM). Data were analyzed by one-way ANOVA and Duncan′s multiple range test. For Tetric Flow, Grandio Flow, Filtek Supreme XT Flow, and Admira Flow, their lowest surface roughness values were obtained in Mylar Strip and PoGo groups. For Compoglass Flow, there were no significant differences between Mylar Strip, PoGo, and OptraPol. For Filtek Z250, the lowest surface roughness value was obtained with Mylar Strip. In light of the surface roughness results obtained, one-step polishing systems seemed to be a good choice for polishing flowable composites.抄録全体を表示PDF形式でダウンロード (849K) -
Kunio IKEMURA, Kensuke ICHIZAWA, Mariko YOSHIDA, So ITO, Takeshi ENDO2008 年 27 巻 6 号 p. 765-774
発行日: 2008年
公開日: 2009/04/30
ジャーナル フリーThe aims of this study were to investigate the photoinitiation behaviors of acylphosphine oxide (APO) and bisacylphosphine oxide (BAPO) derivatives in comparison to D,L-camphorquinone (CQ)/tertiary amine (EDAB) system. Fifty six kinds of experimental unfilled, light-cured resins were prepared using APO, BAPO, CQ, EDAB, resin monomers, and adhesive monomers. The measurements of ultraviolet-visible (UV-VIS) spectroscopy, photopolymerization with differential scanning calorimeter (photo-DSC) and degree of conversion (DC) determination were performed. Results showed that the UV-VIS spectra of all APO and BAPO derivatives possessed λmax ranging between 365 and 416 nm. Their photoinitiation behaviors were not influenced by acidic adhesive monomers formulated in unfilled Bis-GMA-based resins (p<0.05). Although BAPO exhibited higher reactivity than CQ/EDAB in unfilled 6-methacryloyloxyhexcyl phosphonoacetate (6-MHPA)/ 2-hydroxyethyl methacrylate (HEMA) and 6-MHPA/glycerol monomethacrylate (GM)-based resins, it was found that there were no statistically significant differences in DC (%) between BAPO [44.2(6.5)–51.2(4.3)] and CQ/EDAB [42.4(4.4)–47.5(3.7)] (p<0.05). It was concluded that APO and BAPO photoinitiators exhibited reactivity comparable to that of CQ/tertiary amine system.抄録全体を表示PDF形式でダウンロード (795K) -
Yumushan GUNAY, Cem KURTOGLU, Arzu ATAY, Banu KARAYAZGAN, Cihan Cem GU ...2008 年 27 巻 6 号 p. 775-779
発行日: 2008年
公開日: 2009/04/30
ジャーナル フリーThe purpose of this research was to investigate if physical properties could be improved by incorporating a tulle reinforcement material into a maxillofacial silicone elastomer. A-2186 silicone elastomer was used in this study. The study group consisted of 20 elastomer specimens incorporated with tulle and fabricated in dumbbell-shaped silicone patterns using ASTM D412 and D624 standards. The control group consisted of 20 elastomer specimens fabricated without tulle. Tensile strength, ultimate elongation, and tear strength of all specimens were measured and analyzed. Statistical analyses were performed using Mann–Whitney U test with a statistical significance at 95% confidence level. It was found that the tensile and tear strengths of tulle-incorporated maxillofacial silicone elastomer were higher than those without tulle incorporation (p<0.05). Therefore, findings of this study suggested that tulle successfully reinforced a maxillofacial silicone elastomer by providing it with better mechanical properties and augmented strength — especially for the delicate edges of maxillofacial prostheses.抄録全体を表示PDF形式でダウンロード (462K) -
Eriko TAKANASHI, Ryuzo KISHIKAWA, Masaomi IKEDA, Norimichi INAI, Masay ...2008 年 27 巻 6 号 p. 780-786
発行日: 2008年
公開日: 2009/04/30
ジャーナル フリーThe purpose of this investigation was to measure and compare both the surface roughness and gloss of flowable composites polished with standardized silicone carbide (SiC) papers. Four flowable and two conventional composites were used in this study. Polymerized specimens were subjected to a polishing procedure comprising 12 sequential steps from coarser to finer grits of SiC paper. At the initial polishing stage, flowable composites were more sensitive to the size of the polishing particles and thus yielded surfaces rougher than the conventional composites. Surface roughness became stable when polishing particles less than 13 μm size were used. However, although surface roughness was reduced, an esthetic gloss quality was not achieved on the resultant polished surface. On the influence of filler shape, composites with spherical fillers seemed to have the upper-hand advantage of attaining a high gloss by polishing. On the influence of polishing particle size, it was suggested that polishing should be completed with polishing particles less than 12 μm size so as to achieve clinically satisfactory surface roughness and gloss.抄録全体を表示PDF形式でダウンロード (487K) -
Akiyoshi SUGAWARA, Kenji FUJIKAWA, Shozo TAKAGI, Laurence C. CHOW2008 年 27 巻 6 号 p. 787-794
発行日: 2008年
公開日: 2009/04/30
ジャーナル フリーA calcium phosphate cement (CPC-1), prepared by mixing an equimolar mixture of tetracalcium phosphate and dicalcium phosphate anhydrous with water, has been shown to be highly biocompatible and osteoconductive. A new type of calcium phosphate cement (CPC-2), prepared by mixing a mixture of α-tricalcium phosphate and calcium carbonate with pH 7.4 sodium phosphate solution, was also reported to be highly biocompatible. The objective of the present study was to compare the osteoconductivities of CPC-1 and CPC-2 when implanted in surgically created defects in the jaw bones of dogs. At 1 month after surgery, implanted CPC-1 was partially replaced by new bone and converted to bone within 6 months. In comparison, at 1 month after surgery, the defect filled with CPC-2 was mostly replaced by new bone. Therefore, bone formation in CPC-2-filled pocket was more rapid than in CPC-1-filled pocket. These findings supported the hypothesis that CPC-2 converted to bone more rapidly than CPC-1.抄録全体を表示PDF形式でダウンロード (755K) -
Alp Erdin KOYUTURK, Adem KUSGOZ, Mustafa ULKER, Cemal YESILYURT2008 年 27 巻 6 号 p. 795-801
発行日: 2008年
公開日: 2009/04/30
ジャーナル フリーThe purpose of this study was to examine the microleakage of three different fissure sealants after they were aged by mechanical loading and thermocycling in vitro. To this end, a bonding agent (Prime & Bond® NT) and three different fissure sealants (Clinpro, Helioseal F, Teethmate F1) were used, whereby microleakage was evaluated using a dye penetration method after mechanical loading and/or thermocycling. Sealant-treated teeth were allocated into four groups: mechanical loading (50,000 times), thermocycling (10,000 times), mechanical loading (50,000 times) + thermocycling (10,000 times), and one control group. For each fissure sealant, both experimental and control groups showed statistically significant differences in average microleakage score (p<0.05). Further, for each fissure sealant, the highest average microleakage score was obtained in mechanical loading + thermocycling group. When comparison was done for each aging method, the average microleakage scores showed statistically significant differences among the three fissure sealants (p<0.05). Based on the results of this study, it was also concluded that it is necessary to develop reliable in vitro test methods for dental materials.抄録全体を表示PDF形式でダウンロード (518K) -
Soichiro IMAMURA, Hidekazu TAKAHASHI, Iwao HAYAKAWA, Paola G. LOYAGA-R ...2008 年 27 巻 6 号 p. 802-808
発行日: 2008年
公開日: 2009/04/30
ジャーナル フリーIn this study, the effects of filler type and polishing on the discoloration of composite resin artificial teeth were examined.
Four types of experimental resins were prepared: one was a matrix resin, while the others were composite resins containing three different types of fillers (nano-sized silica filler with or without silanization, and prepolymerized filler). Specimens were immersed in distilled water, coffee, red wine, or curry. Color change after immersion was measured using a colorimeter. Color difference values (ΔE) and changes in translucency parameter (ΔTP) were statistically analyzed using three-way ANOVA and Tukey's comparison.
On the influence of the polishing factor, statistically significant differences were neither observed in ΔE nor ΔTP between polished and non-polished tooth surfaces. On the contrary, the influences of filler type and discoloration medium, and their interaction thereof, were significant. With unsilanized filler, the ΔE value of composite resin artificial teeth was significantly increased.抄録全体を表示PDF形式でダウンロード (576K) -
Norihisa OKADA, Eitoku MURAOKA, Seiichiro FUJISAWA, Mamoru MACHINO2008 年 27 巻 6 号 p. 809-813
発行日: 2008年
公開日: 2009/04/30
ジャーナル フリーThe purpose of this study was to evaluate the histopathological effects of camphorquinone (CQ) and 9-fluorenone (9F) with or without visible light (VL) irradiation on the oral mucous membranes of mice. VL irradiation resulted in a higher degree of tissue damage after CQ or 9F application, particularly the latter. Necrosis and apoptosis were responsible for the tissue damage after application of either agent in the presence of VL irradiation.抄録全体を表示PDF形式でダウンロード (627K) -
Effect of preparation angles on the precision of zirconia crown copings fabricated by CAD/CAM systemFlorian BEUER, Daniel EDELHOFF, Wolfgang GERNET, Michael NAUMANN2008 年 27 巻 6 号 p. 814-820
発行日: 2008年
公開日: 2009/04/30
ジャーナル フリーThe aim of this in vitro study was to evaluate the effects of different preparation angles on the precision of fit of zirconia crown frameworks. Dies were fabricated with three different preparation angles: 4, 8, and 12 degrees total taper. Ten copings were fabricated for each angle by a laboratory and a milling-center CAD/CAM system. After cementation, cross-sections were obtained and cement gaps were measured.
Preparation angle (ANOVA, p<0.01) and measurement location (ANOVA, p<0.01) exhibited statistically significant influence on the precision of fit. On the other hand, no statistically significant influences were detected between copings prepared using the laboratory and milling-center CAD/CAM systems (ANOVA, p=0.92). All groups showed marginal openings ranging between 36.6 and 45.5 μm.
In light of the results obtained in this study, a preparation angle of 12 degrees is hence recommended with the confidence that the marginal gap will be consistently less than 50 μm.抄録全体を表示PDF形式でダウンロード (519K) -
Arzu TEZVERGIL-MUTLUAY, Lippo V.J. LASSILA, Pekka K. VALLITTU2008 年 27 巻 6 号 p. 821-826
発行日: 2008年
公開日: 2009/04/30
ジャーナル フリーThis study investigated the microtensile bond strength (μTBS) of fiber-reinforced composite (FRC) to dentin using various adhesive systems. Forty eight (n=8/group) human molars were flattened to expose dentin. A layer of preimpregnated unidirectional FRC (everStick) was applied on the dentin surface after treatment with either a single-step self-etching adhesive, two-step self-etching system, or a conventional three-step adhesive system. For the control, particulate filler composite (PFC) (Filtek Z250) layering without FRC was used. After 24-hour water storage at 37°C, the specimens were sectioned, further water-stored at 37°C for 30 days and then tested. Data were analyzed using ANOVA and Tukey's test, and reliability was analyzed with Weibull distribution. μTBS values differed significantly according to the adhesive material used (p<0.05). Single-step self-etching adhesive showed the lowest bond reliability and μTBS values with both FRC and PFC, whereas conventional three-step and two-step self-etching systems showed higher bond reliability and μTBS with both materials.抄録全体を表示PDF形式でダウンロード (432K) -
Tomonori MATSUNO, Yoshiya HASHIMOTO, Seita ADACHI, Kazuhiko OMATA, Yam ...2008 年 27 巻 6 号 p. 827-834
発行日: 2008年
公開日: 2009/04/30
ジャーナル フリーA novel, injectable bone tissue engineering material was developed that consisted of β-tricalcium phosphate (β-TCP) beads as the solid phase and alginate as the gel phase. To prepare the instantaneously formed composite scaffold, an aqueous calcium chloride solution was dried on the surface of β-TCP beads and crosslinked with an alginic acid sodium solution, thereby forming stable β-TCP beads and alginate gel which were injectable via a syringe. This biodegradable composite was a three-dimensional (3D) material that could be used as an injectable scaffold for bone tissue engineering. In particular, the composite with 2.0 wt% alginate concentration exhibited a compressive strength of 69 kPa in dry conditions, which was significantly higher than that exhibited by 1.0 wt%. Furthermore, mesenchymal stem cells (MSC) were 3D-cultured within the composite and then investigated for osteogenic markers. MSC-loaded composite was subjected to scanning electron microscope (SEM) examination and implanted subcutaneously for in vivo experiment. Results showed that the scaffold provided support for osteogenic differentiation. In light of the encouraging results obtained, this novel injectable composite material may be useful for bone tissue engineering.抄録全体を表示PDF形式でダウンロード (758K) -
Kosuke HONDA, Naoto KINOSHITA, Tetsuya ABE, Makoto HASEGAWA, Akihiko S ...2008 年 27 巻 6 号 p. 835-841
発行日: 2008年
公開日: 2009/04/30
ジャーナル フリーA new version of an air abrasion device, which expelled abrasive sodium bicarbonate powder, was fabricated to remove carious tissue. This device had a motor-driven mechanism to control the amount of powder expelled. The purpose of this study was to estimate the abrading efficacy of this device, in particular the new jet nozzle, for removal of carious dentin. Powder was supplied to the handpiece by a rotary gear attached to the powder control motor. Two types of jet nozzles, a cylinder-type and a bugle-type, were fabricated and evaluated. The duct of bugle-type nozzle had an isthmus to increase the air pressure on the powder and to spread it out in a cone-shaped flow. Results obtained showed that the bugle-type jet nozzle exhibited a more prominent abrasive capability. Compared to the cylinder-type nozzle, it was thus more effective in removing the carious dentin which remained in the undercut region of the cavities.抄録全体を表示PDF形式でダウンロード (592K) -
Goro NISHIGAWA, Yukinori MARUO, Masao IRIE, Morihiko OKA, Kumiko YOSHI ...2008 年 27 巻 6 号 p. 842-848
発行日: 2008年
公開日: 2009/04/30
ジャーナル フリーThe purpose of this study was to evaluate how ultrasonic cleaning of silica-coated zirconia surfaces would influence the latter&prim;s bond strength to resin luting material. Forty zirconia specimens were divided into four groups: one air abrasion group and three silica-coated groups. Silica-coated specimens were cleaned with distilled water using an ultrasonic cleaner after tribochemical silica coating and then divided into three groups according to cleaning durations: 1 minute, 5 minutes, or without cleaning. Following which, resin luting material was polymerized against the specimens. After storage in water for 24 hours, the specimens were subjected to shear bond strength test. Shear bond strength of silica-coated group without cleaning was significantly higher than the other three groups, but there were no statistically significant differences among the three latter groups. SEM images suggested visible differences among the treatment methods. With EDXS analysis, it was revealed that ultrasonic cleaning decreased the silica content on the treated surfaces. Therefore, results showed that ultrasonic cleaning of tribochemically silica-coated zirconia surfaces decreased the adhesion efficacy to resin luting material.抄録全体を表示PDF形式でダウンロード (553K) -
Luiz F. VALANDRO, Mutlu ÖZCAN, Regina AMARAL, Aleska VANDERLEI, M ...2008 年 27 巻 6 号 p. 849-855
発行日: 2008年
公開日: 2009/04/30
ジャーナル フリーThis study tested the bond strength of a resin cement to a glass-infiltrated zirconia-alumina ceramic after three conditioning methods and using two test methods (shear-SBS versus microtensile-MTBS). Ceramic blocks for MTBS and ceramic disks for SBS were fabricated. Three surface conditioning (SC) methods were evaluated: (1) 110-μm Al2O3+silanization; (2) Chairside silica coating+silanization; (3) Laboratory silica coating+silanization. Following surface conditioning, the resin cement (Panavia F) was bonded to the conditioned ceramics. Although no statistically significant differences (p=0.1076) were seen between the test methods, results yielded with the different surface conditioning methods showed statistically significant differences (p<0.0001) (SC2=SC3>SC1). As for the interaction between the factors, two-way ANOVA showed that it was not statistically significant (p=0.1443). MTBS test resulted in predominantly mixed failure (85%), but SBS test resulted in exclusively adhesive failure. On the effects of different surface conditioning methods, chairside and laboratory tribochemical silica coating followed by silanization showed higher bond strength results compared to those of aluminum oxide abrasion and silanization, independent of the test method employed.抄録全体を表示PDF形式でダウンロード (475K) -
Takahito KANIE, Akihiko KADOKAWA, Hiroyuki ARIKAWA, Koichi FUJII, Seij ...2008 年 27 巻 6 号 p. 856-861
発行日: 2008年
公開日: 2009/04/30
ジャーナル フリーWe investigated the viscosity and mechanical properties of experimental light-curing soft lining materials based on six commercially available urethane (meth)acrylate oligomers. The viscosities of the six oligomers were 1.9, 20.6, 26.8, 144.0, 185.3, and 8803.4 Pa·s at 25°C. Two monomers (ethyl- and butyl-methacrylate) were added at 20 wt% to these oligomers to decrease the viscosity, resulting in viscosity reductions of 0.2 to 13.6 Pa·s for the six oligomers. The mechanical properties (compressive modulus, Shore A hardness, and tensile strength) were measured after two times light-polymerization for 3 min. The addition of the monomers to the oligomers only slightly changed the mechanical properties, in contrast to the large viscosity changes. Based on these results, it appears that the addition of ethyl- or butyl-methacrylate monomers is useful for decreasing the viscosity of experimental light-curing soft lining materials without changing their mechanical properties.抄録全体を表示PDF形式でダウンロード (441K)
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