著者

Takeshi NAKAMURA Makoto HAYASHI Muneaki TAMURA Masahiro KAKETANI Tomoka ITO Toshiki TAKAMIZAWA Yusuke SUZUKI Takuya YASUKAWA Akiyoshi SUGAWARA Osamu TAKEICHI

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.2022-250, (Released:2023-03-18)

参考文献数

32

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The recently developed biphasic calcium phosphate cement (BCPC) consists of α-tricalcium phosphate-tetracalcium phosphate as the solid phase and calcium phosphate solution as the liquid phase. BCPC powder is composed of a single solid solution with a monomodal size distribution. Here, we used a bacterial leakage model to examine the utility of BCPC as a seal for root-end filling. We prepared large (median particle size=9.96 µm; BCPC-L) and small (median particle size=4.84 µm; BCPC-S) BCPC powders. In total, 45 single-rooted teeth were instrumented, resected at the root-end, and retrofilled with experimental materials. Mineral trioxide aggregate (MTA) was used as the control. After visual confirmation of BCPC powder size and retrofilling quality by microscopy, bacterial leakage tests were conducted using Enterococcus faecalis. The bacterial leakage tests did not reveal any significant differences between BCPC-S and MTA. Our findings suggest that BCPC-S is useful for root-end filling.

著者

Akiko Takatsuki-Hira Masahiro Kaketani Kohei Shimizu Takahito Tamura Takeshi Nakamura Yurika Toyama Takayuki Yoneyama Osamu Takeichi

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

pp.20-0543, (Released:2021-02-17)

参考文献数

40

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Purpose: This study aimed to examine novel techniques using prototype endodontic obturators to obturate a resin-based sealer.Methods: Powder-liquid ratios of MetaSEAL Soft were changed to obtain suitable root canal sealing, and the physical properties for various powder-liquid ratios were analyzed according to ISO-6876. Tensile bond strength was also examined. Prototype endodontic obturators with a combination of thread numbers and pitch angles were analyzed for sealing ability after MetaSEAL Soft was obturated in simulated root canals.Results: Powder-liquid ratios of 1.0:1, 1.1:1, 1.2:1, and 1.3:1 showed suitable physical properties; however, flow for 1.4:1 was below a standard value. Tensile bond strength increased gradually when the powder-liquid ratio changed from 1.0:1 to 1.3:1, and 1.3:1 and 1.4:1 showed the highest and lowest bond strengths, respectively. Sealing ability increased when pitch angles of the obturators were 5°, 8°, and 11°; 11° showed the best results. Similarly, sealing ability increased when the thread number was 12, 17, and 22 pitches; 22 showed the best results.Conclusion: These findings suggest that the prototype endodontic obturator can be useful for obturating MetaSEAL Soft, and a powder-liquid ratio of 1.3:1 MetaSEAL Soft may be the most suitable for achieving excellent sealing.

著者

Kae Ishii Keisuke Hatori Osamu Takeichi Kosuke Makino Kazuma Himi Hiroki Komiya 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.17-0439, (Released:2018-11-15)

参考文献数

31

被引用文献数

1

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It has been reported that Forkhead box transcription factor class O3a (Foxo3a) is expressed in rheumatoid arthritis, a chronic inflammatory condition accompanied by bone resorption, and plays a role in its pathology. However, it has remained unclear whether Foxo3a is involved in the pathogenesis of periapical granulomas. The present study was performed to compare the expression of Foxo3a in periapical granulomas and healthy gingival tissues. Samples were obtained surgically from patients, and subjected to hematoxylin-eosin staining for histopathologic diagnosis. Two-color immunofluorescence staining was also performed using antibodies against Foxo3a and markers for three types of inflammatory cells: neutrophils, T lymphocytes, and B lymphocytes. This revealed that Foxo3a was expressed in all three cell types in periapical granulomas but not in healthy gingival tissues. Foxo3a was expressed in 82.1%, 78.3%, and 77.5% of neutrophils, T lymphocytes, and B lymphocytes, respectively, and statistical analysis using the Kruskal-Wallis test followed by the Steel-Dwass test showed no significant difference of Foxo3a expression among the three cell types. Our results suggest that Foxo3a transcription factors may be involved in the pathogenesis of periapical granulomas.

著者

Hiroshi Kudo Osamu Takeichi Kosuke Makino Keisuke Hatori 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.17-0412, (Released:2018-08-12)

参考文献数

45

被引用文献数

6

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Silent information regulator 2 homolog 1 (SIRT1) inhibits oxidative injury and has anti-inflammatory effects. SIRT1 may be involved in healing of periapical periodontitis; however, SIRT1 expression in periapical periodontitis lesions has not been investigated. This study evaluated SIRT1 expression and a marker of oxidative stress—8-hydroxy-2’-deoxyguanosine (8-OHdG)—in periapical granulomas. First, we used real-time polymerase chain reaction to determine whether U-937 monocytes express SIRT1. U-937 cells treated with the SIRT1 activator resveratrol exhibited the highest SIRT1 mRNA level after 6-h incubation. By contrast, treating cells with the SIRT1 inhibitor sirtinol returned SIRT1 expression level to that of the control. In addition, immunocytochemical analysis using cytospin specimens showed that U-937 cells co-expressed SIRT1 and Ki-67. Dual-color immunofluorescence imaging showed that round cells in periapical granulomas co-expressed SIRT1 and 8-OHdG; however, neither was expressed in healthy gingival tissues. The number of 8-OHdG-expressing cells was significantly greater than the number of SIRT1-expressing cells. Our findings suggest that macrophages express SIRT1 and that wound healing in periapical granulomas is enhanced by a SIRT1-mediated reduction in the level of oxidative stress.

著者

Hisashi Suguro Osamu Takeichi Makoto Hayashi Teinosuke Okamura Akiko Hira Yoriyuki Hirano 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.17-0092, (Released:2018-04-16)

参考文献数

25

被引用文献数

4

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Transparent epoxy resin root canal models were used to evaluate vertical condensation techniques for obturating lateral canals. The root canal model was configured with a straight main root canal and four right-angled lateral canals at 1.0 and 3.0 mm from the apex. Root canal obturation was performed with Thermafil, Obtura II, or NT condenser. Obturation volume in lateral canals was measured by three-dimensional microcomputed tomography, and one-way analysis of variance was used to analyze differences between groups. Lateral canals at 1.0 and 3.0 mm were uniformly filled by all obturation methods. Among the three obturation methods, Thermafil resulted in the highest obturation volumes for all lateral canals.