著者

Akifumi TAKAHASHI Tomohiro TAKAGAKI Takahiro WADA Motohiro UO Toru NIKAIDO Junji TAGAMI

出版者

The Japanese Society for Dental Materials and Devices

雑誌

Dental Materials Journal (ISSN:02874547)

巻号頁・発行日

vol.37, no.5, pp.734-739, 2018-09-27 (Released:2018-09-30)

参考文献数

23

被引用文献数

20

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The effects of contamination and cleaning methods on bonding of self-adhesive resin cement to zirconia ceramics were examined. Airborne particle-abraded zirconia (Zpex Smile) specimens were divided into the following four groups: control (con), contaminated with saliva and cleaned with tap water (HS), cleaned with Ivoclean (IC), and cleaned with Multi Etchant (ME). The pretreated specimens were bonded using three self-adhesive resin cements, and tensile bond strengths were measured using a universal testing machine at a crosshead speed of 2 mm/min. Con and IC groups showed significantly higher bond strength than those of HS and ME groups. Separately, the surface chemical composition of the groups was determined using X-ray photoelectron spectroscopy (XPS). XPS revealed that the N/Zr ratio increased in the HS group but decreased in the IC and ME groups. Cleaning agents can improve the adverse effect of saliva contamination on zirconia, but this effect varies depending on the product.

著者

Tomoyo OKAZAKI Hiroyasu KOIZUMI Hiroshi NOGAWA Akihisa KODAIRA Tomotaro NIHEI Hideo MATSUMURA

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.2017-183, (Released:2018-01-26)

参考文献数

33

被引用文献数

1

---

This study aimed to investigate how different compositions of experimental silane-based primers in a methyl methacrylate solution containing 3-(trimethoxysilyl)propyl methacrylate (3-TMSPMA) or 3-(4-methacryloyloxyphenyl)propyl trimethoxysilane (3-MPPTS) might act as silicon dioxide bonding agents. With or without post-silanization heat treatment, primer-treated quartz discs were bonded using the MMA-TBB resin and their bond strengths were evaluated. The disks were primed with one of the following materials: 1 mol% 3-TMSPMA, 2 mol% 3-TMSPMA, 1 mol% 3-MPPTS, and 2 mol% 3-MPPTS. Shear bond strength was determined both before and after thermocycling. Statistical analyses were performed with non-parametric procedure (Kruskal-Wallis, Mann-Whitney U, and Steel-Dwass tests). Both primers were effective with heat treatment to enhance bonding between quartz and the MMA-TBB, and the bonding durability of the 1 and 2 mol% 3-MPPTS (16.8 and 24.9 MPa) with heat groups was significantly higher than in the 1 and 2 mol% 3-TMSPMA (5.4 and 9.8 MPa) with heat groups.

著者

Seiichiro FUJISAWA Yoshinori KADOMA Yasuo KOMODA

出版者

The Japanese Society for Dental Materials and Devices

雑誌

Dental Materials Journal (ISSN:02874547)

巻号頁・発行日

vol.10, no.1, pp.18-26,97, 1991-06-25 (Released:2009-02-12)

参考文献数

10

被引用文献数

2 2

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生体膜と歯科用接着性モノマーの相互作用のメカニズムを分子レベルで明らかにするため,4-META及びその関連化合物(4-methacryloyloxyethoxycarbonyl-phthalic Acid 4-MET,フタール酸,無水フタール酸)とジパルミトイルホスファチジルコリン(DPPC)リポソームとの相互作用をNMR及びDSCを用いて研究した。pH 7.4で,4-META,及び無水フタール酸により誘起されたDPPCリポソームのNMRケミカルシフトと相転移温度の変化は,フタール酸のそれより大きかった。DPPC/4-METAリポソーム系のNMRスペクトルはDPPC/4-METリポソーム系と類似した。これは4-METAが加水分解し4-METになった為と推察された。さらに,4-META及びその関連化合物のヒト赤血球に及ぼす影響を検討した。4-META,及び無水フタール酸は4-MET及びフタール酸に比べて高い溶血性を示した。このことは,イオン化する化合物は生体膜に透入できないことを示した。

著者

Shunichi SUDA Akimasa TSUJIMOTO Wayne W. BARKMEIER Kie NOJIRI Yuko NAGURA Toshiki TAKAMIZAWA Mark A. LATTA 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.2017-059, (Released:2017-11-23)

参考文献数

51

被引用文献数

20

---

The effect of phosphoric acid pre-etching on enamel bond fatigue durability of universal adhesives and two-step self-etch adhesives was investigated. Four universal adhesives and three two-step self-etch adhesives were used. The initial shear bond strengths and shear fatigue strengths to enamel with and without phosphoric acid pre-etching using the adhesives were determined. SEM observations were also conducted. Phosphoric acid pre-etching of enamel was found to increase the bond fatigue durability of universal adhesives, but its effect on two-step self-etch adhesives was material-dependent. In addition, some universal adhesives with phosphoric acid preetching showed similar bond fatigue durability to the two-step self-etch adhesives, although the bond fatigue durability of universal adhesives in self-etch mode was lower than that of the two-step self-etch adhesives. Phosphoric acid pre-etching enhances enamel bond fatigue durability of universal adhesives, but the effect of phosphoric acid pre-etching on the bond fatigue durability of two-step self-etch adhesives was material-dependent.

著者

TETÈ Stefano ZIZZARI Vincenzo Luca BORELLI Bruna DE COLLI Marianna ZARA Susi SORRENTINO Roberto SCARANO Antonio GHERLONE Enrico CATALDI Amelia ZARONE Fernando

出版者

The Japanese Society for Dental Materials and Devices

雑誌

Dental Materials Journal (ISSN:02874547)

巻号頁・発行日

vol.33, no.1, pp.7-15, 2014

被引用文献数

31

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Human gingival fibroblasts (HGFs) were cultured onto CAD/CAM zirconia (Group A), CAD/CAM zirconia after polishing (Group B), CAD/CAM lithium disilicate after polishing (Group C), and feldspathic ceramic (Group D) to evaluate their proliferation and adhesion potential. After 3 h, HGF adhesion was similar in all groups. Later, HGFs closely adhered to surfaces, particularly onto groups B, C and D, acquiring an elongated shape. Proliferation assay showed no differences in cell viability among the groups after 24 h, while significant increase was shown after 72 h in Groups B and C. After 24 h, similar Collagen I levels were found in all groups, while after 72 h Groups B and C revealed a deep reduction in respect to the 24 h level. <i>In vitro</i>, HGF behavior may reflect variability in soft tissue response to different surface materials for prosthetic restorations, and support that polished zirconia is able to achieve a better integration <i>in vivo</i> in respect to the other materials.

著者

Futoshi KOMINE Shingo KAMIO Hiroki TAKATA Shogo YAGAWA Serina TAGUCHI Kohei TAGUCHI Akiko HASHIGUCHI Hideo MATSUMURA

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.2017-057, (Released:2017-09-07)

参考文献数

41

被引用文献数

3

---

This study evaluated the effect of zirconia framework design on fracture load of implant-supported zirconia-based prostheses after thermal cycling and mechanical loading. Three different zirconia framework designs were investigated: uniform-thickness (UNI), anatomic (ANA), and supported anatomic (SUP) designs. Each framework was layered with feldspathic porcelain (ZAC group) or indirect composite material (ZIC group). The specimens then underwent fracture load testing after thermal cycling and cyclic loading. In the ZAC group, mean fracture load was significantly lower for UNI design specimens than for the other framework designs. In the ZIC group, there was no significant difference in mean fracture load between ANA design specimens and either UNI or SUP design specimens. To improve fracture resistance of implant-supported zirconia-based prostheses after artificial aging, uniformly thick layering material and appropriate lingual support with zirconia frameworks should be provided.

著者

Carlos LOPEZ-SUAREZ Veronica RODRIGUEZ Jesus PELAEZ Ruben AGUSTIN-PANADERO Maria J. SUAREZ

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.2016-391, (Released:2017-08-25)

参考文献数

41

被引用文献数

17

---

The purpose of this study was to evaluate and to compare the fracture load and the fracture pattern of monolithic and veneered zirconia posterior fixed dental prostheses (FDPs). Twenty standardized steel dies were prepared to receive posterior 3-unit FDPs. Specimens were randomly divided into 2 groups (n=10): (1) Lava Zirconia, and (2) Lava Plus. All FDPs were cemented using glass ionomer cement and subjected to thermal and mechanical cycling at 5–55ºC with a 30-s dwell time for 120,000 masticatory cycles. All specimens were subjected to a three-point bending test until fracture. Data were statistically analyzed using Student’s t test, paired t-test and Weibull statistics (α=0.05). No differences were observed in fracture load between the groups. Veneering ceramic fractured before than framework in veneered zirconia group. The fracture pattern was different. The tested groups demonstrated clinically acceptable fracture load values. Monolithic zirconia solves the chipping problem.

著者

Masahiro IIJIMA Kyotaro KAWAGUCHI Naohiko KAWAMURA Shuichi ITO Takashi SAITO Itaru MIZOGUCHI

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.36, no.4, pp.461-468, 2017-07-25 (Released:2017-07-26)

参考文献数

30

被引用文献数

14

---

We investigated single application of pastes containing a surface reaction-type pre-reacted glass-ionomer (S-PRG) filler on enamel demineralization. Human enamel blocks were polished using pastes containing S-PRG filler (0, 5, and 30%) and immersed in demineralizing solution for 5 days with daily change of solutions. The pH measurement and nanoindentation testing was carried out during the immersion period, and the enamel surfaces were examined using scanning electron microscopy and atomic force microscopy. A non-fluoride paste and a hydroxyapatite-containing paste were used for comparison. The specimens polished with the S-PRG filler-containing paste exhibited acid-neutralizing properties, which became stronger with an increasing S-PRG filler content. Following immersion in the demineralizing solution, specimens polished with the S-PRG filler-containing paste exhibited significantly greater hardness and elastic modulus values than those polished with the other pastes and exhibited a smoother surface than did the other specimens. Pastes containing S-PRG filler inhibits the demineralization of enamel.

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

---

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

Kazutaka HIRAI Akimasa TSUJIMOTO Kie NOJIRI Hirofumi UETA Toshiki TAKAMIZAWA Wayne W. BARKMEIER Mark A. LATTA 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.2016-019, (Released:2017-06-23)

参考文献数

31

被引用文献数

4

---

The influence of photoirradiation conditions on dentin bond durability and interfacial characteristics of universal adhesives was investigated. Universal adhesives were applied to the dentin surfaces and photoirradiated with 100 mW/cm2 for 40 s, 200 mW/cm2 for 20 s, and 400 mW/cm2 for 10 s. A resin composite was bonded to dentin to determine shear bond strength after 24 h water storage and 30,000 thermal cycles, and water contact angle of cured adhesive were measured by the sessile drop method. Greater dentin bond strengths after 24 h water storage and 30,000 thermal cycles were achieved under these conditions at light intensity exceeding 200 mW/cm2. Universal adhesives photoirradiated above 200 mW/cm2 exhibited significantly higher water contact angles than those at 100 mW/cm2. The results of this study suggested that the photoirradiation conditions affect the dentin bond durability and interfacial characteristics of universal adhesives even at the same total energy.

著者

Takuya YASUKAWA Makoto HAYASHI Natsuko TANABE Hiromasa TSUDA Yusuke SUZUKI Takayuki KAWATO Naoto SUZUKI Masao MAENO Bunnai OGISO

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.2016-313, (Released:2017-02-22)

参考文献数

30

被引用文献数

9

---

Mineral trioxide aggregate (MTA) has excellent biocompatibility as well as bioactivity, including an ability to induce osteoblast differentiation. We examined the effects of the calcium-sensing receptor (CaSR) on osteogenic gene expression induced by MTA. MC3T3-E1 cells were cultured with or without (control) MTA. The expression levels of Runx2, type I collagen, and CaSR genes were analyzed by real-time polymerase chain reaction and their products were measured using enzyme-linked immunosorbent assays. The levels were increased significantly in cells exposed to MTA compared with control. Next, MC3T3-E1 cells were cultured with MTA and EGTA (a calcium chelator), because calcium ions were released continuously from MTA into the culture. Expression levels were decreased to control levels by MTA plus EGTA. NPS2143 (a CaSR antagonist) also reduced MTA-induced gene expression. These results suggest that MTA induced osteogenic gene expressions of Runx2 and type I collagen via CaSR in MC3T3-E1 cells.

著者

Akimasa TSUJIMOTO Wayne W. BARKMEIER Toshiki TAKAMIZAWA Mark A. LATTA 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.2016-131, (Released:2017-02-01)

参考文献数

32

被引用文献数

49

---

The purpose of this study was to investigate the depth of cure, flexural properties and volumetric shrinkage of low and high viscosity bulk-fill giomers and resin composites. Depth of cure and flexural properties were determined according to ISO 4049, and volumetric shrinkage was measured using a dilatometer. The depths of cure of giomers were significantly lower than those of resin composites, regardless of photo polymerization times. No difference in flexural strength and modulus was found among either high or low viscosity bulk fill materials. Volumetric shrinkage of low and high viscosity bulk-fill resin composites was significantly less than low and high viscosity giomers. Depth of cure of both low and high viscosity bulk-fill materials is time dependent. Flexural strength and modulus of high viscosity or low viscosity bulk-fill giomer or resin composite materials are not different for their respective category. Resin composites exhibited less polymerization shrinkage than giomers.

著者

KAMISHIMA Naoko IKEDA Takatsumi SANO Hidehiko

出版者

一般社団法人日本歯科理工学会

雑誌

Dental materials journal (ISSN:02874547)

巻号頁・発行日

vol.24, no.3, pp.428-432, 2005-09

被引用文献数

17 59

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The purpose of this study was to evaluate the colors of resin composites used for the layering technique, as well as the translucency at various thickness. For the purpose of calculating the translucency parameter (TP), black and white backings were used to evaluate the CIELAB parameters of Filtek Supreme (3M) and Gradia Direct (GC) disks of various thicknesses (0.5, 1.0, 2.0, 3.0 and 4.0mm) and of three different shades (enamel-shade, body-shade, and opaque-shade). As for the color of each shade, it was evaluated using 4mm thick specimens on the white backing. Regarding TP, the opaque-shades were less translucent than the other shades. It was also found that translucency increased exponentially as thickness was reduced-regardless of shade. Regarding color, enamel-shades were more bluish (especially in GD) compared to the other shades, and the opaque-shades displayed a brighter and yellowish characteristic. In the layering technique, it is fundamental to have an accurate knowledge about the translucency and colors of the materials/shades used.

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

---

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

Taro IWASAKI Futoshi KOMINE Ryosuke FUSHIKI Kei KUBOCHI Mitsuyo SHINOHARA Hideo MATSUMURA

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.35, no.3, pp.461-469, 2016-05-31 (Released:2016-06-01)

参考文献数

36

被引用文献数

15

---

This study evaluated shear bond strengths of a layering indirect composite material to a zirconia framework material treated with tribochemical silica coating. Zirconia disks were divided into two groups: ZR-PRE (airborne-particle abrasion) and ZR-PLU (tribochemical silica coating). Indirect composite was bonded to zirconia treated with one of the following primers: Clearfil Ceramic Primer (CCP), Clearfil Mega Bond Primer with Clearfil Porcelain Bond Activator (MGP+Act), ESPE-Sil (SIL), Estenia Opaque Primer, MR. Bond, Super-Bond PZ Primer Liquid A with Liquid B (PZA+PZB), and Super-Bond PZ Primer Liquid B (PZB), or no treatment. Shear bond testing was performed at 0 and 20,000 thermocycles. Post-thermocycling shear bond strengths of ZR-PLU were higher than those of ZR-PRE in CCP, MGP+Act, SIL, PZA+PZB, and PZB groups. Application of silane yielded better durable bond strengths of a layering indirect composite material to a tribochemically silica-coated zirconia framework material.

著者

Akimasa TSUJIMOTO Wayne W. BARKMEIER Toshiki TAKAMIZAWA Mark A. LATTA 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.35, no.3, pp.418-424, 2016-05-31 (Released:2016-06-01)

参考文献数

37

被引用文献数

1 46

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The mechanical properties, volumetric shrinkage and depth of cure of a short fiber-reinforced resin composite (SFRC) were investigated in this study and compared to both a bulk fill resin composite (BFRC) and conventional glass/ceramic-filled resin composite (CGRC). Fracture toughness, flexural properties, volumetric shrinkage and depth of cure of the SFRC, BFRC and CGRC were measured. SFRC had significantly higher fracture toughness than BFRCs and CGRCs. The flexural properties of SFRC were comparable with BFRCs and CGRCs. SFRC showed significantly lower volumetric shrinkage than the other tested resin composites. The depth of cure of the SFRC was similar to BFRCs and higher than CGRCs. The data from this laboratory investigation suggests that SFRC exhibits improvements in fracture toughness, volumetric shrinkage and depth of cure when compared with CGRC, but depth of cure of SFRC was similar to BFRC.

著者

Fumi YOSHIDA Akimasa TSUJIMOTO Ryo ISHII Kie NOJIRI Toshiki TAKAMIZAWA Masashi MIYAZAKI Mark A. LATTA

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.34, no.6, pp.855-862, 2015-11-27 (Released:2015-12-01)

参考文献数

28

被引用文献数

2 37

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This study investigates the influence of surface treatment of contaminated lithium disilicate and leucite glass ceramic restorations on the bonding efficacy of universal adhesives. Lithium disilicate and leucite glass ceramics were contaminated with saliva, and then cleaned using distilled water (SC), or 37% phosphoric acid (TE), or hydrofluoric acid (CE). Specimens without contamination served as controls. The surface free energy was determined by measuring the contact angles formed when the three test liquids were placed on the specimens. Bond strengths of the universal adhesives were also measured. Saliva contamination and surface treatment of ceramic surfaces significantly influenced the surface free energy. The bond strengths of universal adhesives were also affected by surface treatment and the choice of adhesive materials. Our data suggest that saliva contamination of lithum disilicate and leucite glass ceramics significantly impaired the bonding of the universal adhesives, and reduced the surface free energy of the ceramics.

著者

Kie NOJIRI Akimasa TSUJIMOTO Takayuki SUZUKI Syo SHIBASAKI Saki MATSUYOSHI 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

vol.34, no.5, pp.611-617, 2015-10-02 (Released:2015-10-05)

参考文献数

28

被引用文献数

5 8

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In this study, we investigated the influence of light intensity on the surface-free energy and dentin bond strength of single-step selfetch adhesives. The adhesives were applied to the dentin surfaces of bovine mandibular incisors and cured with light intensities of 0 (no irradiation), 200, 400, and 600 mW/cm2. Surface-free energies were determined by measuring the contact angles of three test liquids placed on the cured adhesives. Dentin bond strengths of the specimens were also measured. Polymerization with a higher light intensity resulted in a lower surface-free energy of the cured adhesives. The greatest bond strength was achieved when a light intensity of 400 mW/cm2 or greater was used. Our data suggest that the surface-free energy and dentin bond strength of single-step self-etch adhesives are affected by light intensity of the curing unit.

著者

宮川 修 渡辺 孝一 大川 成剛 中野 周二 小林 正義 塩川 延洋

出版者

一般社団法人日本歯科理工学会

雑誌

Dental Materials Journal (ISSN:02874547)

巻号頁・発行日

vol.8, no.2, pp.175-185, 285, 1989-12-25

被引用文献数

44 69

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燐酸塩を結合剤とし,アルミナ/シリカを耐火材とする埋没材の鋳型に市販のチタンを鋳造した。鋳造体の表層構造をEPMAによって調べ,それが次の4層からなることを明らかにした。すなわち,第1は反応層(焼き付き層),第2は酸素とAlで安定化したα相の層,第3はSi, P, C及び酸素が所々に濃縮された層,そして第4は針状または板状結晶の集合体である。鋳造体の体積が大きいほど,また鋳型温度が高いと,各層が厚くなり,針状結晶も粗大になる。 この多層構造は鋳込みの際に埋没材が溶湯に巻き込まれてできたものではないことは実験結果から明らかである。埋没材の還元されやすい成分の分解によって生じた元素が鋳造体の内部へ拡散してできたものと考えられる。

著者

María CURA M Victoria FUENTES Laura CEBALLOS

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.2014-248, (Released:2015-02-24)

参考文献数

48

被引用文献数

13

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This study evaluated the effects of several low-concentration bleaching products on microtensile bond strength (µTBS) to enamel at different elapsed times after the bleaching treatment. One hundred and fifty bovine incisors were divided into five groups: No treatment, 10% carbamide peroxide (Opalescence), 10% hydrogen peroxide (Opalescence Treswhite Supreme), 3% carbamide peroxide plus lactoperoxidase (WhiteKin), or 3% carbamide peroxide plus 2.7% carbamide peroxide (Clysiden Kit Express). All treatments lasted 4 weeks. After bleaching treatment or non-treatment, teeth were restored immediately, at 1, 3, 7, or 14 days after bleaching and submitted to µTBS test. Data were analyzed by ANOVA and Tukey’s test (p<0.05). For WhiteKin and Clysiden, µTBS to enamel was significantly reduced immediately, at 1, 3 and 7 days after bleaching. At 14 days after bleaching, similar µTBS values were obtained regardless of bleaching product. Therefore, while over-the-counter (OTC) products might affect bond strength to enamel, this effect was no longer observed after 14 days.