著者

Atsushi Tateno Masatake Asano Daisuke Akita Taku Toriumi Niina Tsurumachi-Iwasaki Tomohiko Kazama Yoshinori Arai Taro Matsumoto Koichiro Kano Masaki Honda

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

pp.18-0458, (Released:2019-10-21)

参考文献数

45

被引用文献数

13

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Tissue engineering is a promising approach to supplement existing treatment strategies for craniofacial bone regeneration. In this study, a type I collagen scaffold made from a recombinant peptide (RCP) with an Arg-Gly-Asp motif was developed, and its effect on regeneration in critical-size mandibular bone defects was evaluated. Additionally, the combined effect of the scaffold and lipid-free dedifferentiated fat (DFAT) cells was assessed. Briefly, DFAT cells were separated from mature adipocytes by using a ceiling culture technique based on buoyancy. A 3 cm × 4 cm critical-size bone defect was created in the rat mandible, and regeneration was evaluated by using RCP with DFAT cells. Then, cultured DFAT cells and adipose-derived stem cells (ASCs) were seeded onto RCP scaffolds (DFAT/RCP and ASC/RCP) and implanted into the bone defects. Micro-computed tomography imaging at 8 weeks after implantation showed significantly greater bone regeneration in the DFAT/RCP group than in the ASC/RCP and RCP-alone groups. Similarly, histological analysis showed significantly greater bone width in the DFAT/RCP group than in the ASC/RCP and RCP-alone groups. These findings suggest that DFAT/RCP is effective for bone formation in critical-size bone defects and that DFAT cells are a promising source for bone regeneration.

著者

Kabun Yamauchi Akimasa Tsujimoto Carlos A. Jurado Yusuke Shimatani Yuko Nagura Toshiki Takamizawa Wayne W. Barkmeier Mark A. Latta Masashi Miyazaki

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

pp.18-0433, (Released:2019-10-21)

参考文献数

31

被引用文献数

28

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In this study, dentin bond fatigue resistance and interfacial science characteristics of universal adhesives through etch-and-rinse and self-etch modes were investigated. Resin composite was bonded to human dentin with four universal adhesives, namely, Adhese Universal, All-Bond Universal, G-Premio Bond, and Scotchbond Universal Adhesive. The initial bond strengths, bond fatigue strengths, and interfacial science characteristics of the universal adhesives with dentin through etch-and-rinse and self-etch modes were determined. Bond fatigue resistance (initial bond strength and bond fatigue strength) of universal adhesives in etch-and-rinse mode showed no significant difference in contrast to that in self-etch mode and was material-dependent regardless of the etching mode. Although phosphoric acid conditioning of dentin did not have a strong impact on the bond fatigue resistance, surface free energy and parameters of dentin were significantly decreased by etching and by application of universal adhesives regardless of etching mode. Changes in γS and γSh for when universal adhesive was applied to etched and ground dentin were significantly different depending on the adhesive. The results suggest that bonding performance of universal adhesives was effective in both etching modes; however, bonding mechanisms may be different for each.

著者

Yoriyuki Hirano Makoto Hayashi Muneaki Tamura Fumihiko Yoshino Ayaka Yoshida Mitsuaki Masubuchi Kenichi Imai Bunnai Ogiso

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

pp.18-0455, (Released:2019-10-05)

参考文献数

39

被引用文献数

10

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Oral diseases generally have certain bacteria associated with them. Non-thermal atmospheric pressure plasma (NTAP), generated at atmospheric pressure and room temperature, incorporates several molecules, including reactive oxygen species, that can inactivate various bacteria including oral pathogens. For this reason, several NTAP devices have been developed to treat oral diseases. Use of noble gases can enhance the bactericidal efficacy of NTAP, but this requires additional gas supply equipment. Therefore, a new NTAP device that employs ambient air as the working gas was developed. The device generates non-thermal atmospheric pressure air plasma. Here, the singlet oxygen (1O2) levels generated, their bactericidal effects on oral pathogens (Streptococcus mutans, Porphyromonas gingivalis, and Enterococcus faecalis), and the bacterial oxidative stress they imposed were measured. 1O2 generation in phosphatebuffered saline was assessed qualitatively using electron spin resonance (ESR) spectroscopy, and bactericidal efficacy was evaluated by counting of colony-forming units/mL. Bacterial oxidative stress was determined by measurement of hydrogen peroxide (H2O2) and superoxide dismutase (SOD) activity. ESR indicated that the level of 1O2 increased significantly and time-dependently, and was inversely correlated with distance, but the bactericidal effects were correlated only with treatment time (not distance) as H2O2 increased and SOD levels decreased, suggesting that the new device has potential applicability for treatment of oral disease.

著者

Junya Aoki Keiji Shinozuka Kanako Yamagata Ryota Nakamura Takako Sato Saori Ohtani Shouhei Ogisawa Keiichi Yanagawa Morio Tonogi

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

pp.18-0422, (Released:2019-09-20)

参考文献数

21

被引用文献数

3

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This study evaluated the effect of maxillary advancement surgery on the size of the pharyngeal airway space (PAS). Lateral cephalometric radiographs were collected for 90 patients (29 men and 61 women; average age, 27.2 ± 8.1 years) before (T1) and 1 year after (T2) maxillary advancement surgery. Horizontal and vertical changes in the maxilla and PAS were measured and classified by distance. The maxilla was advanced horizontally by 2.9 ± 1.7 mm and vertically by 2.7 ± 1.4 mm. Upward maxillary movement of ≥4 mm significantly increased PAS (mean change in PAS, 2.6 mm), and upward maxillary movement significantly decreased the posterior nasal spine to the P-point. Only patients with vertical advancement ≥4 mm and horizontal advancement of 3 mm had significant increases in all three PAS parameters. Although forward maxillary movement is believed to have a large effect on PAS, it is suggest that upward vertical movement is more effective for improving PAS. Both the extent and direction of maxillar movement should be considered. Future studies should use cone-beam computed tomography to evaluate the effect of axial direction and differences in PAS.

著者

Satsuki Saito Mariko Ohtsu Masatake Asano Tomohiko Ishigami

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

pp.18-0411, (Released:2019-09-20)

参考文献数

24

被引用文献数

4

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Accurate evaluation of the anti-cancer effects of ouabain, a cardiac glycoside, requires an understanding of its signaling pathway. This study examined the effects of ouabain stimulation on spontaneous interleukin (IL)-8 and IL-1α secretion in the HSC3 oral squamous cell carcinoma cell line. IL-8 secretion was reduced and IL-1α secretion was increased in the cells. Real-time polymerase chain reaction confirmed that these changes were regulated at the transcriptional level. Further analysis revealed that ouabain stimulation induced phosphorylation of activator protein (AP)-1 components (c-Jun and c-Fos) but not nuclear factor kappa B (NF-κB) components (p65 and p50). A luciferase assay demonstrated that the NF-κB-binding site located at 1 kb upstream of the TATA box in the IL-8 gene contributed to the reduction in IL-8 secretion. Pre-incubation of the cells with BAPTA-AM and L-glutathione increased IL-8 secretion, which indicates that Ca2+ ions and reactive oxygen species are associated with the ouabain-mediated reduction in IL-8 levels. The inhibitory effect of ouabain was attributed to reduced nuclear translocation of the NF-κB p65 subunit. Taken together, these findings indicate that ouabain exerts opposing effects on transcription factors NF-κB and AP-1.

著者

Yoshiaki Nomura Tomoaki Matsuyama Kakuhiro Fukai Ayako Okada Mitsuo Ida Noriaki Yamauchi Hiroyuki Hanamura Yoshihide Yabuki Kazuhiko Watanabe Motoko Sugawara Yasuhiko Imanishi Norihiro Koizumi Yoshinori Murano Atsushi Nishiyama Yoshiteru Fukukawa Ryoko Otsuka Nobuhiro Hanada

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

pp.18-0288, (Released:2019-09-20)

参考文献数

14

被引用文献数

11

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Screening is a fundamental strategy for early detection, treatment, and prevention of progression of oral disease and those at high risk for oral disease. While numerous screening tools exist, questionnaires, and saliva tests are often suitable for screening. The questionnaire based on the Precede-Proceed model was developed, validated, and elucidated on the structural interrelationship between these two methods. In the current investigation, 311 adults had this questionnaire and saliva testing administered simultaneously during an occupational health checkup. The questionnaire was validated by classical test theory, item response theory, and path analysis. Through structural equation modeling, it was found that self-care guidance may be an important role of the family dentist. In addition, self-awareness of oral symptoms was significantly related to saliva test results. However, self-administered questionnaires and saliva tests together may provide more information than either of them alone for the detection, treatment, and prevention of progression of oral disease. Thus, simultaneous application of self-administered questionnaires and saliva tests is recommended during oral health checkups for adults.

著者

Yoshinori Sasai Yusuke Suzuki Yoshimasa Takeuchi

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.61, no.3, pp.481-482, 2019 (Released:2019-08-28)

参考文献数

3

被引用文献数

5

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The social security system, including the national health insurance system, in Japan has been maintained at a world-class level since 1974. However, an increase in the number of elderly people, and a decrease in the working generation, caused by a declining birthrate, represents a serious issue for the system both in the present and future. This report analyzes the key problems in the current insurance system and also considers how they can be handled in the future.

著者

Shinji Okada Ayano Katagiri Hiroto Saito Jun Lee Kinuyo Ohara Toshimitsu Iinuma Koichi Iwata

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.61, no.2, pp.370-378, 2019 (Released:2019-06-18)

参考文献数

40

被引用文献数

10

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Peripheral nerve injury can induce neuroplastic changes in the central nervous system and result in neuropathic pain. This study investigated functional involvement in dorsal paratrigeminal nucleus (dPa5) and nucleus tractus solitarii (NTS) neurons projecting to the parabrachial nucleus (PBN) after trigeminal nerve injury. Anatomical quantification was performed based on phosphorylated extracellular signal-regulated kinase (pERK) expression underlying orofacial neuropathic pain associated with infraorbital nerve chronic constriction injury (ION-CCI) in rats. ION-CCI rats exhibited heat and mechanical hypersensitivity in the ipsilateral upper lip. After injection of retrograde tracer fluorogold (FG) into the contralateral PBN, ION-CCI rats received capsaicin or noxious mechanical stimulation to the upper lip. The total number of FG-labeled neurons in dPa5 and NTS did not change after ION-CCI, and pERK expression in dPa5 did not differ between sham and ION-CCI rats. In the NTS contralateral to ION-CCI, the number of pERK-immunoreactive neurons and percentage of pERK-immunoreactive FG-labeled PBN projection neurons were increased after capsaicin stimulation in ION-CCI rats. The present findings suggest that enhanced noxious inputs from the NTS to the PBN after trigeminal nerve injury modulates PBN neuron activity, which accompanies the affective components of orofacial neuropathic pain.

著者

Kentaro Okamura Hiroyasu Koizumi Akihisa Kodaira Hiroshi Nogawa Takayuki Yoneyama

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.61, no.2, pp.358-363, 2019 (Released:2019-06-18)

参考文献数

21

被引用文献数

8

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The purpose of this study was to evaluate the surface properties and gloss of CAD/CAM composites after toothbrush abrasion testing. Four CAD/CAM composites for molars (Cerasmart 300, Estelite P block, Katana Avencia P block, and KZR-CAD HR3 Gammatheta), one CAD/CAM composite for premolars (Shofu Block HC Hard), and one feldspathic ceramics (Vitablocs Mark II) were assessed. Knoop hardness number, gloss, and surface roughness (Ra, Rz, and Sa) were measured before and after toothbrush abrasion testing. Knoop hardness number values were in the order Vitablocs Mark II > Katana Avencia P block > Estelite P Block > Shofu Block HC Hard > Cerasmart 300 > KZR-CAD HR3 Gammatheta. After testing, the gloss of Estelite P block and KZR-CAD HR3 Gammatheta was greatly decreased and surface roughness was greatly increased. Periodic recall and re-polishing may thus be necessary when these products are used clinically.

著者

Fumiaki Kimura Futoshi Komine Kei Kubochi Shogo Yagawa

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.61, no.2, pp.327-334, 2019 (Released:2019-06-18)

参考文献数

25

被引用文献数

2

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This study investigated bond strength of CAD/CAM-manufactured composite resin and ceramic veneers to a zirconia framework and analyzed the effect of treatments of veneer surfaces. A CAD/CAM resin-based (AVE) composite or lithium disilicate ceramic (IEC) block was used as the veneer material. AVE and IEC specimens were assigned to receive one of three surface treatments (n = 22): no surface treatment, acid-etching with 9.5% hydrofluoric acid gel, and airborne-particle abrasion with alumina particles. Zirconia disks and AVE or IEC specimens in each group were bonded with a resin-based luting agent, and shear bond strength of the specimens was measured at 0 and 20,000 thermocycles. Significant differences were assessed by the Steel-Dwass test for multiple comparisons and Mann-Whitney U-test (α = 0.05). As compared with other surface treatments, bond strengths were significantly higher at 0 and 20,000 thermocycles in the airborne-particle abraded AVE and acid-etched IEC specimens. Airborne-particle abrasion of the surface of AVE specimens increased bond strength between AVE veneers and zirconia frameworks, while hydrofluoric acid treatment enhanced bond strength between IEC veneers and zirconia frameworks.

著者

Toshiki Takamizawa Akimasa Tsujimoto Ryo Ishii Maho Ujiie Mami Kawazu Toshie Hidari Takayuki Suzuki Masashi Miyazaki

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.61, no.2, pp.276-283, 2019 (Released:2019-06-18)

参考文献数

33

被引用文献数

4

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The purpose of this study was to examine the effect of desensitizing dentifrices containing stannous fluoride (SnF2) on dentinal tubule occlusion. Two experimental dentifrices with the same ingredients but different SnF2 concentrations (Group II, 0.4% w/w; Group III, 0.454% w/w) were used; distilled water was used in the control group (Group I). Third molars were collected from Japanese and American dental patients. The crowns were removed and sectioned to obtain dentin discs, which were further cut into quarters. Thirty-six specimens each from Japanese and American patients were divided into three sets (n = 12 each) and assigned to each of the three treatment groups. The specimens were brushed for 10 s twice per day for 4 days. After treatment, the discs were observed by scanning electron microscopy, and the extent of dentinal tubule occlusion in the images was expressed on a five-point categorical scale. Group II and III specimens from Japanese and American patients showed greater dentinal tube occlusion than those from Group I, but the differences were not statistically significant. The present results suggest that both SnF2 concentrations mitigate dentin hypersensitivity, regardless of patient ethnicity.

著者

Hideyuki Imai Hiroyasu Koizumi Akihisa Kodaira Kentaro Okamura Shunsuke Akahane Hideo Matsumura

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.61, no.1, pp.178-183, 2019 (Released:2019-03-28)

参考文献数

16

被引用文献数

1

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This study evaluated the light intensity of light-emitting diode (LED) units and the effects of five laboratory polymerization units on hardness and flexural strength. Two indirect composite materials (Cesead N and Solidex Hardura) were polymerized with five units (α-Light II, Hyper LII, LED Cure Master, Twinkle LED, and α-Light V). The light intensity of the devices was measured with a spectroradiometer. After light exposure, Knoop hardness number, flexural strength, and elastic modulus were determined. Evaluation of light intensity, using a wavelength range of 400 to 500 nm, revealed that the α-Light V and Hyper LII units had the highest light intensity. For the top surface of the two composites, the Knoop hardness number was significantly higher for the α-Light V and Hyper LII. For the two composite materials, flexural strength did not differ among the five polymerizing units. The present results indicate that the Cesead N and Solidex Hardura composites can be adequately polymerized with laboratory LED units.

著者

Shinji Okada Hiroto Saito Yutaka Matsuura Lou Mikuzuki Shiori Sugawara Hiroki Onose Junichi Asaka Kinuyo Ohara Jun Lee Toshimitsu Iinuma Ayano Katagiri Koichi Iwata

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.61, no.1, pp.146-155, 2019 (Released:2019-03-28)

参考文献数

77

被引用文献数

2

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Bright light stimulation of the eye activates trigeminal subnucleus caudalis (Vc) neurons in rats. Sensory information is conveyed to the Vc via the trigeminal ganglion (TG). Thus, it is likely that TG neurons respond to photic stimulation and are involved in photic hypersensitivity. However, the mechanisms underlying this process are unclear. Therefore, the hypothesis in this study is bright light stimulation enhances the excitability of TG neurons involved in photic hypersensitivity. Expressions of calcitonin gene-related peptide (CGRP) and neuronal nitric oxide synthase (nNOS) were significantly higher in TG neurons from 5 min to 12 h after photic stimulation of the eye. Phosphorylation of extracellular signal-regulated kinase1/2 (pERK1/2) was enhanced in TG neurons within 5 min after photic stimulation, while pERK1/2 immunoreactivity in satellite glial cells (SGCs) persisted for more than 12 h after the stimulus. Activation of SGCs was observed from 5 min to 2 h. Expression of CGRP, nNOS, and pERK1/2 was observed in small and medium TG neurons, and activation of SGCs and pERK1/2-immunoreactive SGCs encircling large TG neurons was accelerated after stimulation. These results suggest that upregulation of CGRP, nNOS, and pERK1/2 within the TG is involved in photic hypersensitivity.

著者

Yasuyo Takahashi Kotoe Mayahara Rena Fushiki Rieko Matsuike Noriyoshi Shimizu

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

pp.18-0001, (Released:2019-02-01)

参考文献数

24

被引用文献数

4

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High-magnitude mechanical strain inhibits bone nodule formation by reducing expression of bone morphogenetic protein-2 (BMP-2), Runt-related transcription factor 2 (Runx2), and muscle segment homeobox 2 (Msx2). Mechanical strain also induces production of proinflammatory factor prostaglandin E2 (PGE2) by osteoblasts. We measured the effect of mechanical strain-induced PGE2 production on bone nodule formation and expression levels of bone formation-related factors. Osteoblast-like cells isolated from fetal rat calvariae were loaded with 18% cyclic tension force (TF) for 48 h in the presence or absence of NS-398, a selective inhibitor of cyclooxygenase-2. To investigate the effect of TF-induced PGE2 on bone formation, bone nodule area on day 21 was measured by von Kossa staining. BMP-2, Runx2, and Msx2 expression levels were examined at 1 day after TF loading. Bone nodule formation was significantly inhibited by TF but was restored to control level by PGE2 inhibition. Furthermore, TF loading-induced reductions in expressions of these factors were restored to control level by PGE2 suppression. These results indicate that PGE2 production induced by high-magnitude mechanical strain inhibits bone nodule formation by reducing expression levels of bone formation-related factors.

著者

Janaina C. O. Sardi Cristiane Duque Flávia S. Mariano Iza T. A. Peixoto José F. Höfling Reginaldo B. Gonçalves

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.52, no.2, pp.177-185, 2010 (Released:2010-06-25)

参考文献数

64

被引用文献数

27 53

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Although the main reservoir of Candida spp. is believed to be the buccal mucosa, these microorganisms can coaggregate with bacteria in subgingival biofilm and adhere to epithelial cells. Such interactions are associated with the capacity of Candida spp. to invade gingival conjunctive tissue, and may be important in the microbial colonization that contributes to progression of oral alterations caused by diabetes mellitus, some medications, and immunosuppressive diseases such as AIDS. In addition, immune deficiency can result in proliferation of Candida spp. and germination of forms that are more virulent and have a higher capacity to adhere to and penetrate cells in host tissues. The virulence factors of Candida spp. increase host susceptibility to proliferation of these microorganisms and are likely to be important in the study of periodontal disease. Herein, we briefly review the literature pertaining to the role of Candida spp. in periodontal disease, and consider the main virulence factors, the host immune response to these microorganisms, and the effect of concomitant immunosuppressive conditions. (J Oral Sci 52, 177-185, 2010)

著者

Tomohiro Yasumitsu Osamu Shimizu Hiroshi Shiratsuchi Yusuke Miyake Yoshiyuki Yonehara

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.60, no.4, pp.595-600, 2018 (Released:2018-12-27)

参考文献数

33

被引用文献数

6

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The aim of this study was to determine the localization of aquaporin-5 (AQP5), transforming growth factor-β1 (TGF-β1) and laminin during regeneration of the rat submandibular gland. After duct ligation for 7 days, the regenerating glands were collected on days 0, 1, 3, 7, and 14 after ligation release to study the process of regeneration. Immunohistochemical staining revealed apical expression of AQP5 in many acinar cells, strong expression in intercalated ducts (ICDs) of the normal submandibular gland at Day 14, and strong expression in duct-like structures (DLSs) during regeneration from Day 0 to 7. However, a few AQP5-negative acinar cells were detected during regeneration. At Day 0, immunopositivity for TGF-β1 was detected in connective tissue. At Days 3 and 7 during regeneration, TGF-β1 immunostaining was observed in DLSs, which were surrounded by α-smooth muscle actin-positive thickened myoepithelial cells. Laminin staining was strong in the thickened basement membrane of DLSs at Day 3 during regeneration, but weak around acinar cells at Day 14. These findings suggest that TGF-β1 is involved in the environment around DLSs, myoepithelial cells and laminin, that DLSs have the same functional properties as ICDs, and that AQP5-negative acinar cells may be mucous cells.

著者

Takahisa Okubo Naoki Tsukimura Takashi Taniyama Manabu Ishijima Kourosh Nakhaei Naser M. Rezaei Makoto Hirota Wonhee Park Daisuke Akita Atsushi Tateno Tomohiko Ishigami Takahiro Ogawa

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.60, no.4, pp.567-573, 2018 (Released:2018-12-27)

参考文献数

23

被引用文献数

9

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Titanium mesh plate (Ti mesh) used for bone augmentation inadvertently comes into contact with medical gloves during trimming and bending. We tested the hypotheses that glove contact degrades the biological capability of Ti mesh and that ultraviolet treatment (UV) can restore this capability. Three groups of Ti mesh specimens were prepared: as-received (AR), after glove contact (GC), and after glove contact followed by UV treatment. The AR and GC meshes were hydrophobic, but GC mesh was more hydrophobic. AR and GC meshes had significant amounts of surface carbon, and Si content was higher for GC mesh than for AR mesh. UV mesh was hydrophilic, and carbon and silicon content values were significantly lower in this group than in the AR and GC groups. The number, alkaline phosphatase activity, and mineralization ability of attached osteoblasts were significantly lower in the GC group than in the AR group and markedly higher in the UV group than in the AR group. In conclusion, glove contact caused chemical contamination of Ti mesh, which significantly reduced its bioactivity. UV treatment restored bioactivity in contaminated Ti mesh, which outperformed even the baseline Ti mesh.

著者

Hisanori Ito Takashi Kifune Misa Ishiyama Satoko Iwasa Hiroki Takei Tomokazu Hasegawa Masatake Asano Tetsuo Shirakawa

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.60, no.4, pp.544-551, 2018 (Released:2018-12-27)

参考文献数

30

被引用文献数

5

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Hypoxia after traumatic injuries to a tooth is one of the causes of subsequent root resorption. Inflammatory cytokines produced under hypoxic conditions are associated with root resorption, but the mechanism has not been fully understood. In this study, the role of hypoxia-inducible factor-1 (HIF-1) signaling in the regulation of CCAAT (cytosine-cytosine-adenosine-adenosine-thymidine)/enhancer-binding protein-β (C/EBPβ) and the receptor activator of nuclear factor kappa-B ligand (RANKL) expressions in immortalized human periodontal ligament (PDL) cells was investigated. PDL cells cultured under a hypoxic condition showed an increase in the expression of C/EBPβ and RANKL messenger RNAs (mRNAs), whereas the expression of osteoprotegerin and HIF-1α mRNAs was unaffected. Hypoxia had no effects on the secretion of interleukin (IL)-1β, IL-6, IL-8, IL-17A, tumor necrosis factor-alpha, macrophage migration inhibitory factor, monocyte chemoattractant protein-1, and macrophage colony-stimulating factor in the culture media. Treatment of the cells with dimethyloxaloylglycine, a competitive HIF prolyl hydroxylase inhibitor, significantly increased the expression of C/EBPβ and RANKL mRNAs. This suggested that the hypoxia-induced elevation of C/EBPβ and RANKL mRNAs was dependent on the HIF-1 activity. PDL cells transfected with a specific small interfering RNA designed to target the C/EBPβ gene showed a significant suppression of the RANKL mRNA. These findings indicated that C/EBPβ may play an important role in tooth root resorption via RANKL activation in hypoxia-exposed PDL cells.

著者

Takashi Kifune Hisanori Ito Misa Ishiyama Satoko Iwasa Hiroki Takei Tomokazu Hasegawa Masatake Asano Tetsuo Shirakawa

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.60, no.4, pp.519-525, 2018 (Released:2018-12-27)

参考文献数

32

被引用文献数

11

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Hypoxia induces complex cellular responses that are mediated by a key transcription factor, hypoxia-inducible factor-1 (HIF-1). HIF-1 promotes production of cytokines and angiogenic factors and contributes to recovery of injured tissues. In the present study, expressions of angiogenin (ANG) and vascular endothelial growth factor (VEGF), which are potent angiogenic factors in mammalian tissues, were examined in immortalized fibroblasts exposed to hypoxia. After 24 h of exposure to hypoxia, ANG and VEGF mRNAs expressions were significantly elevated in periodontal ligament (PDL) fibroblasts but not in embryonic fibroblasts. Hypoxia also increased productions of ANG and VEGF proteins in PDL fibroblasts. HIF-1α mRNA expression was not affected by hypoxia in either fibroblast, although HIF-1α protein expression was enhanced after exposure to hypoxia. Treatment of PDL fibroblasts with dimethyloxaloylglycine, a prolyl hydroxylase inhibitor that stabilizes the HIF-1α protein, significantly increased expressions of ANG and VEGF mRNAs under normoxia. This suggests that stabilization of HIF-1α is crucial for upregulation of ANG and VEGF in PDL fibroblasts. These results indicate that, under hypoxic conditions, HIF-1α upregulates synthesis of ANG and VEGF in PDL fibroblasts and promotes angiogenesis.

著者

Tatsuro Suzuki Masahiro Kondo Ikuko Shibuta Hidekazu Nagashima Naoyuki Sugano Shuichi Sato Koichi Iwata

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.60, no.4, pp.500-506, 2018 (Released:2018-12-27)

参考文献数

25

被引用文献数

1

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The inferior alveolar nerve (IAN) comprises several types of sensory fibers. To clarify whether each type of primary afferent is regenerated comparably after injury, we developed a model of complete IAN transection (IANX) in mice. A retrograde tracer, fluoro-gold, injected into the mental skin was transferred to the cell bodies of a subset of isolectin B4 (IB4)-binding (non-peptidergic C) or CGRP-positive (peptidergic C) neurons at 2 weeks post-axotomy, indicating that the injured C afferents had regenerated anatomically. IANX led to a decrease of IB4-binding and CGRP immunoreactivity (IR) in the trigeminal ganglion (TG) and within the trigeminal spinal subnucleus caudalis (Vc) (i.e. terminals of the central branch of TG neurons). Two weeks after IANX, the reduction in IB4-binding activity and CGRP expression in the TG recovered to the control level; however, IB4-binding within the Vc did not, suggesting that central branch non-peptidergic neurons remained impaired. Two weeks after IANX, pinching or heat stimulus-induced extracellular signal-regulated kinase phosphorylation (pERK) was restored to the control level, but in the case of pinch stimulation the distribution pattern of pERK-IR cells was altered in the Vc. Taken together, our results support the possibility that peptidergic neurons regenerate more efficiently than non-peptidergic neurons after trigeminal nerve injury.