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
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

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

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

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
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

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.
著者
Hiroshi NOGAWA Hiroyasu KOIZUMI Osamu SAIKI Haruto HIRABA Mitsuo NAKAMURA 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.2014-227, (Released:2015-02-24)
参考文献数
34
被引用文献数
2 12

The purpose of this study was to evaluate the shear bond strength and durability of 4-META/MMA-TBB resin to human enamel. A self-etching primer that contained 4-META (Teeth Primer, TP) and 35–45% or 60–65% concentrations of phosphoric acid (K-Etchant Gel, KE, and Super Bond C&B Red Activator, RA) were used as the surface treatment agents. A methyl methacrylate (MMA)-based self-polymerizing resin (Super-Bond C&B) was used as a luting agent. The shear bond strength was determined both pre and post thermocycling. The results were statistically analyzed with a non-parametric procedure. The post-thermocycling shear bond strength of the TP group was significantly higher than that of other groups, and that of the KE group was significantly higher compared with the RA group. These results demonstrated that 4-META was effective. Furthermore, when the degree of tooth demineralization was compared, surface treatment with less demineralization using TP was the most effective treatment.
著者
Yusuke SUZUKI Makoto HAYASHI Takuya YASUKAWA Hiroshi KOBAYASHI Kosuke MAKINO Yoriyuki HIRANO Shozo TAKAGI Laurence C. CHOW 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.2014-255, (Released:2015-02-25)
参考文献数
31
被引用文献数
5

Aim of this study was to develop a novel fluorapatite-forming calcium phosphate cement (FA-CPC) with tricalcium silicate (TCS) for endodontic applications and to examine its in vitro and in vivo characteristics. The FA-CPC powder consisted of 62.8% CaHPO4, 30.8% CaCO3, and 6.4% NaF. One part of TCS was combined with 9 parts of FA-CPC powder (FA-CPC with TCS). A 1.5 M phosphate solution was used as cement liquid. Setting time (ST), diametral tensile strength (DTS), phase composition by X-ray diffraction (XRD), and cement alkalinity were analyzed. Cement biocompatibility was assessed using rat subcutaneous model. Cement ST was 10.3±0.6 min and DTS was 3.89±0.76 MPa. XRD patterns showed that highly crystalline apatitic material was the only significant phase present and pH value was approximate 11.0. FA-CPC with TCS demonstrated similar biocompatibility as that of mineral trioxide aggregate control. These results suggest that FA-CPC with TCS may be useful for endodontic applications.
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

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
Futoshi KOMINE Kohei TAGUCHI Ryosuke FUSHIKI Shingo KAMIO Taro IWASAKI 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.33, no.5, pp.607-613, 2014-09-30 (Released:2014-10-01)
参考文献数
29
被引用文献数
1 16

This study evaluated fracture load of single-tooth, implant-supported, zirconia-based, porcelain- and indirect composite-layered restorations after artificial aging. Forty-four zirconia-based molar restorations were fabricated on implant abutments and divided into four groups, namely, zirconia-based all-ceramic restorations (ZAC group) and three types of zirconia-based composite-layered restorations (ZIC-P, ZIC-E, and ZIC groups). Before layering an indirect composite material, the zirconia copings in the ZIC-P and ZIC-E groups were primed with Clearfil Photo Bond and Estenia Opaque Primer, respectively. All restorations were cemented on the abutments with glass-ionomer cement and then subjected to thermal cycling and cyclic loading. All specimens survived thermal cycling and cyclic loading. The fracture load of the ZIC-P group (2.72 kN) was not significantly different from that of the ZAC group (3.05 kN). The fracture load of the zirconia-based composite-layered restoration primed with Clearfil Photo Bond (ZIC-P) was comparable to that of the zirconia-based all-ceramic restoration (ZAC) after artificial aging.
著者
Ayako KAWABE Ichiro NAKAGAWA Zuisei KANNO Yusuke TSUTSUMI Takao HANAWA Takashi ONO
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.638-647, 2014-09-30 (Released:2014-10-01)
参考文献数
50
被引用文献数
1 12

Titanium (Ti) is widely used for oral cavity biomedical devices. However, because it penetrates the mucosa and exists partially external to the tissue, it sometimes induces tissue inflammation, minor infection, or peri-implantitis due to oral bacteria after implantation and causes serious consequences. We have previously shown that poly(ethylene glycol) (PEG)- electrodeposited Ti inhibits bacterial adhesion and biofilm formation. However, the effect of the PEG coating in body fluid is still unclear. In this study, we investigated bacterial colony morphology and biofilm formation on PEG-electrodeposited Ti in comparison with untreated Ti in the presence of saliva. After 48 h incubation, Streptococcus mutans biofilms adhered on the untreated Ti were rigid and cohesive, while those on the PEG-electrodeposited were loose and were easily washed off. These results indicate electrodeposited-PEG layers inhibit the biofilm formation on Ti in the presence of saliva.
著者
Stefano TETÈ Vincenzo Luca ZIZZARI Bruna BORELLI Marianna DE COLLI Susi ZARA Roberto SORRENTINO Antonio SCARANO Enrico GHERLONE Amelia CATALDI Fernando ZARONE
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.1, pp.7-15, 2014-01-30 (Released:2014-02-01)
参考文献数
34
被引用文献数
5 31

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. In vitro, 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 in vivo in respect to the other materials.
著者
Maho SHIOZAWA Hidekazu TAKAHASHI Werner J. FINGER Naohiko IWASAKI
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.32, no.1, pp.150-155, 2013-01-31 (Released:2013-02-01)
参考文献数
14
被引用文献数
2 4

Aim of this study was to investigate effects of space thickness and consistency of wash materials on sulcus depth reproduction with silicone impressions, low (L), medium (M), and very high consistency (VH), using two-step putty-wash technique. Impressions were taken from truncated cones with 50-, 100-, or 200-μm-wide sulci, using the combinations L+VH or M+VH and different space thickness for wash materials: 2 mm (ST2), 1 mm (ST1), and approximately 25 μm (ST0.025). Sulcus depth reproduction tended to increase with increasing sulcus width. Sulcus reproduction of ST0.025 was deeper than those of the other groups. At 100- and 200-μm sulcus widths, sulcus reproductions of ST1 and ST2 with L+HV were deeper than with M+HV. Regardless of consistency, the thin spacer produced deep reproduction. Adequate 0.5 mm sulcus reproductions were obtained with 100 and 200 μm wide sulci and 1- and 2-mm spacer widths, combined with low consistency impression material.