著者

Kana HAYASHI Hiroyasu KUROKAWA Makoto SAEGUSA Ryota AOKI Toshiki TAKAMIZAWA Atsushi KAMIMOTO Masashi MIYAZAKI

出版者

The Japanese Society for Dental Materials and Devices

雑誌

Dental Materials Journal (ISSN:02874547)

巻号頁・発行日

pp.2023-007, (Released:2023-07-15)

参考文献数

29

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This study aimed to determine the influence of surface roughness of the color adjustment potential restoration of universal resin composites. A structural colored resin composite (Omnichroma, OC) and a pigment-employed universal shade resin composite (Beautifil Unishade, BU) were used. Each resin composite was placed in a cavity to determine its ability to match the color of artificial teeth. The surface of the resin composites was polished with #800- or #2000-grit SiC paper before performing color measurements. One-way analysis of variance and Tukey post hoc tests were performed (α=0.05). The color difference (ΔE*ab) ranged from 2.5–3.9 for OC and 1.8–8.7 for BU. OC has a more stable color adjustment than BU. The color adjustment potential of universal resin composites was affected by the surface roughness of the restorations.

著者

Mone SHOJI Hiroyasu KUROKAWA Nao TAKAHASHI Runa SUGIMURA Toshiki TAKAMIZAWA Kei IWASE Shun KATSUKI Masashi MIYAZAKI

出版者

The Japanese Society for Dental Materials and Devices

雑誌

Dental Materials Journal (ISSN:02874547)

巻号頁・発行日

pp.2021-318, (Released:2022-03-24)

参考文献数

42

被引用文献数

5

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The purpose of this study was to investigate the protective effect of a glass ionomer cement (GIC) consisting of fluoro-zinc-silicate glass on the demineralization of bovine dentin using the ultrasonic pulse-echo method. The findings were compared with those obtained using a conventional GIC. Slabs of dentin from bovine teeth were sliced, shaped into a rectangular form, and immersed in 0.5 M ethylenediaminetetraacetic acid solution at 25ºC for 6 days, followed by storage in distilled water for 3 days. After demineralization, they were immersed in artificial saliva with and without the GIC specimens. The propagation times of the longitudinal ultrasonic waves in the samples were measured. The ultrasonic velocities of the fluoro-zinc-silicate glass-containing GICs were significantly increased 2–3 days after the start of the experiment and showed an upward trend thereafter. These findings indicate that the GICs containing fluoro-zinc-silicate glass might exhibit the potential to promote remineralization in the dentin.

著者

Nao TAKAHASHI Hiroyasu KUROKAWA Kengo WAKAMATSU Eizo HIROKANE Toshiki TAKAMIZAWA Masashi MIYAZAKI Nobuya KITAHARA

出版者

The Japanese Society for Dental Materials and Devices

雑誌

Dental Materials Journal (ISSN:02874547)

巻号頁・発行日

pp.2021-154, (Released:2021-09-23)

参考文献数

27

被引用文献数

7

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This study investigated the bonding performance of two different types of resin cements to computer-aided design/computer-aided manufacturing (CAD/CAM) composite blocks based on the shear bond strength (SBS) test. A silane-containing self-adhesive resin cement (Panavia SA Cement Universal) and resin luting cement (Block HC Cem) with a primer, were used. Specimens were fabricated from three different types of CAD/CAM composite blocks, and their surfaces were blasted with alumina. Resin cements were bonded to the specimens, and their SBSs were measured after 15 min, 24 h, and after being subjected to thermal cycling for 10,000 and 30,000 cycles. Three-way ANOVA for bond strength revealed that CAD/CAM composite block, resin cement and storage time significantly influenced the SBS values, and the three-way interactions between the evaluated factors, and all the interactions were significant. It was concluded that the bonding performance of resin cements to CAD/CAM composite blocks were material and storage period dependent.

著者

Tatsuya IIJIMA Hiroyasu KUROKAWA Toshiki TAKAMIZAWA Eizo HIROKANE Nao TAKAHASHI Kengo WAKAMATSU Shunichi SUDA Masashi MIYAZAKI

出版者

The Japanese Society for Dental Materials and Devices

雑誌

Dental Materials Journal (ISSN:02874547)

巻号頁・発行日

pp.2021-011, (Released:2021-06-30)

参考文献数

40

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The purpose of this study was to investigate the ability of polishing paste containing surface pre-reacted glass-ionomer (S-PRG) filler to prevent acidic attack on tooth enamel surfaces. Resin composites were filled in the standardized cavities and finished with silicon carbide paper. These specimens were divided into three groups: the unpolished “control” group, the “PRG” group polished with S-PRG paste, and the “DDP” group polished with diamond-containing polishing paste. Following polishing, the specimens were immersed in a lactic acid buffer solution for 28 days. Optical coherence tomography (OCT) signals were measured to obtain the signal intensity and width at 1/e2 at selected locations on the enamel surface adjacent to the restoration. Although signal intensity significantly increased in all groups, widths at 1/e2 did not change significantly in the PRG group. For both the control and DDP groups, signal intensity and width at 1/e2 increased and decreased over time, respectively.

著者

Nao TAKAHASHI Chiaki YABUKI Hiroyasu KUROKAWA Toshiki TAKAMIZAWA Yuta KASAHARA Makoto SAEGUSA Miho SUZUKI Masashi MIYAZAKI

出版者

The Japanese Society for Dental Materials and Devices

雑誌

Dental Materials Journal (ISSN:02874547)

巻号頁・発行日

pp.2019-247, (Released:2020-05-19)

参考文献数

28

被引用文献数

5

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The aim of this study was to determine the influence of different surface treatments of CAD/CAM composite blocks on bonding effectiveness of resin cements, based on the shear bond strength test and the surface science examination. Specimens were fabricated from two types of CAD/CAM composite blocks (Cerasmart and VITA Enamic), and the specimen surfaces were alumina sandblasted. Specimen surfaces were treated with i) silane, ii) primer, and iii) silane+primer, then two types of cements (Block HC Cem and Super Bond) were bonded. After 24 h storage, bond strengths were measured. Surface free energy measurements were performed of the treated CAD/CAM composite blocks surfaces. The groups ii) and iii) showed significantly higher bond strengths than the group i), apart from VITA Enamic with Block HC Cem. Although the total surface free energy showed different trends in different surface treatments, a similar trend was found in both CAD/CAM composite blocks.

著者

Ryosuke Murayama Yuko Nagura Kabun Yamauchi Nobuyuki Moritake Masayoshi Iino Ryo Ishii Hiroyasu Kurokawa Masashi Miyazaki Yumiko Hosoya

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

pp.17-0256, (Released:2018-07-09)

参考文献数

40

被引用文献数

5

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We used optical coherence tomography to examine the effect of a coating material containing surface reaction-type pre-reacted glass-ionomer (S-PRG) filler on primary enamel demineralization in 18 extracted human primary teeth. The pulp was removed, and each tooth was ultrasonically cleaned with distilled water. Six teeth were treated with 0.1-M lactic acid buffer solution (De group). In the second group (n = 6), a thin film of coating material was applied before demineralization (PRG group). A third group (Control group; n = 6) was maintained in artificial saliva. Using optical coherence tomography, we measured peak signal intensity (dB) and width at 1/e2 (µm) at predetermined locations on the enamel surface and calculated integrated values. All data were analyzed with ANOVA and the Tukey-Kramer test (α = 0.05). Although changes in integrated values differed between groups, there was a small but significant increase in the Control group and a small but significant decrease in the De group. In the PRG group, integrated values were significantly higher at 7 days after the start of the experiment and significantly increased thereafter. Our findings indicate that a coating material containing S-PRG fillers may prevent primary enamel demineralization.

著者

Yukie TAMURA Toshiki TAKAMIZAWA Yutaka SHIMAMURA Shunsuke AKIBA Chiaki YABUKI Arisa IMAI Akimasa TSUJIMOTO Hiroyasu KUROKAWA Masashi MIYAZAKI

出版者

日本歯科理工学会

雑誌

Dental Materials Journal (ISSN:02874547)

巻号頁・発行日

pp.2016-185, (Released:2017-07-12)

参考文献数

30

被引用文献数

12

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The influences of air-powder polishing with glycine or sodium bicarbonate powders on shear bond strengths (SBS) and surface-free energies of universal adhesives were examined. Scotchbond Universal Adhesive (SU, 3M ESPE), G-Premio Bond (GP, GC), Adhese Universal (AU, Ivoclar Vivadent), and All-Bond Universal (AB, Bisco) were used in this study. Bovine dentin surfaces were air polished with glycine or sodium bicarbonate powders prior to the bonding procedure, and resin pastes were bonded to the dentin surface using universal adhesives. SBSs were determined after 24-h storage in distilled water at 37°C. Surface-free energy was then determined by measuring contact angles using three test liquids on dentin surfaces. Significantly lower SBSs were observed for dentin that was air-powder polished and surface-free energies were concomitantly lowered. This study indicated that air-powder polishing influences SBSs and surface-free energies. However, glycine powder produced smaller changes in these surface parameters than sodium bicarbonate.

著者

Chie KANAZAWA Ryosuke MURAYAMA Tetsuya FURUICHI Arisa IMAI Shunichi SUDA Hiroyasu KUROKAWA Toshiki TAKAMIZAWA Masashi MIYAZAKI

出版者

日本歯科理工学会

雑誌

Dental Materials Journal (ISSN:02874547)

巻号頁・発行日

pp.2016-175, (Released:2016-12-06)

参考文献数

28

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This study used an ultrasonic measurement device to monitor the setting behavior of silicone elastomeric impression materials, and the influence of temperature on setting behavior was determined. The ultrasonic device consisted of a pulser-receiver, transducers, and an oscilloscope. The two-way transit time through the mixing material was divided by two to account for the down-and-back travel path; then it was multiplied by the sonic velocity. Analysis of variance and the Tukey honest significant difference test were used. In the early stages of the setting process, most of the ultrasonic energy was absorbed by the elastomers and the second echoes were relatively weak. As the elastomers hardened, the sonic velocities increased until they plateaued. The changes in sonic velocities varied among the elastomers tested, and were affected by temperature conditions. The ultrasonic method used in this study has considerable potential for determining the setting processes of elastomeric impression materials.

著者

Hiroyasu Kurokawa Toshiki Takamizawa Akitomo Rikuta Keishi Tsubota Masashi Miyazaki

出版者

日本大学歯学部

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.57, no.2, pp.101-108, 2015 (Released:2015-06-10)

参考文献数

35

被引用文献数

3 14

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In this clinical study, we evaluated the 3-year clinical performance of a resin composite containing a surface-prereacted glass ionomer (S-PRG) filler (Beautifil II; Shofu Inc., Kyoto, Japan) placed with a single-step self-etch adhesive (BeautiBond; Shofu Inc.) in posterior restorations. Using modified US Public Health Service criteria, two experienced investigators performed clinical evaluations at the baseline, 6 months, 18 months, and 3 years. Color match, marginal adaptation, anatomical form, surface roughness, marginal discoloration, postoperative sensitivity, and secondary caries were evaluated. After 3 years, 26 patients attended the recall and 31 restorations were evaluated. No postoperative sensitivity or secondary caries was observed at any time point, and no restorations failed during the follow-up period. However, surface roughness, marginal adaptation, and marginal discoloration showed deterioration after 3 years. In conclusion, although some clinical changes were observed, resin composite containing S-PRG filler placed with self-etch adhesive exhibited acceptable clinical behavior in posterior restorations. (J Oral Sci 57, 101-108, 2015)

著者

Mayumi KOTAKU Ryosuke MURAYAMA Yutaka SHIMAMURA Fuminori TAKAHASHI Takayuki SUZUKI Hiroyasu KUROKAWA Masashi MIYAZAKI

出版者

日本歯科理工学会

雑誌

Dental Materials Journal (ISSN:02874547)

巻号頁・発行日

vol.33, no.5, pp.648-655, 2014-09-30 (Released:2014-10-01)

参考文献数

33

被引用文献数

11

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Effects of a fluoride-releasing varnish containing surface reaction-type prereacted glass ionomer (S-PRG) filler on dentin demineralization were examined using optical coherence tomography. Bovine incisors that were sliced and treated with undersaturated 0.1 M lactic acid buffer solution (DE group). A thin film of varnish-containing S-PRG filler was applied before demineralization (PRG group). Control was maintained in artificial saliva. Using optical coherence tomography of selected locations on the dentin surface, peak intensity (dB) and width (μm) at 1/e2 were obtained and integrated values calculated. Although alterations in integrated values were different in each group, there was a slight but not significant increase in those for the control group and a slight but significant increase for the De group. For the PRG group, integrated values were doubled seven days after experiment initiation, followed by a significant increase. Fluoride-releasing varnish containing S-PRG fillers prevented dentin demineralization as detected by optical coherence tomography.

著者

Masashi Miyazaki Akimasa Tsujimoto Keishi Tsubota Toshiki Takamizawa Hiroyasu Kurokawa Jeffrey A. Platt

出版者

日本大学歯学部

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.56, no.1, pp.1-9, 2014 (Released:2014-03-15)

参考文献数

90

被引用文献数

8 61

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Improvements in dentin bonding systems have influenced modern restorative dentistry. The desire for minimal invasiveness has resulted in more-conservative cavity design, which basically relies on the effectiveness of current dentin bonding systems. Interaction of adhesives with enamel and dentin is based on two systems, commonly described as etch-and-rinse and self-etch. Priming and bonding agents can be separate or combined, resulting in two- or three-step systems for etch-and-rinse adhesives and one- or two-step systems for self-etch adhesives. Self-etch systems use acidic functional monomers that simultaneously demineralize and impregnate tooth structures. Etch-and-rinse and self-etch systems have advantages and disadvantages, which are primarily related to the simplified bonding procedures required under clinical conditions. Knowledge of the composition, characteristics, and mechanisms of adhesion for each adhesive system is critical in selecting the ideal adhesive materials for clinical use. (J Oral Sci 56, 1-9, 2014)