Yawaka Yasutaka
Faculty of Dental Medicine Division of Dental Medicine Department of Functional Science | Professor |
Office of Admissions | Professor |
Hokkaido University Hospital | Professor |
■Researcher basic information
Researchmap personal page
J-Global ID
Educational Organization
- Bachelor's degree program, School of Dental Medicine
- Doctoral (PhD) degree program, Graduate school of Dental Medicine
■Career
Career
- Apr. 2003 - Mar. 2005
北海道大学病院歯科診療センター, 咬合B(小児歯科専門)外来, 講師 - Apr. 2000 - Mar. 2003
Hokkaido University, Graduate School of Dental Medicine, 助手 - Jun. 1993 - Mar. 2000
北海度大学歯学部, 小児歯科学講座, 助手 - Jan. 1990 - May 1993
Hokkaido University, School of Dental Medicine, 助手 - 1986 - 1989
Hokkaido University, School of Dental Medicine - 1986 - 1989
Medical Staff
Committee Memberships
Position History
- 教育研究評議会評議員, 2014年4月1日 - 2016年3月31日
- 教育研究評議会評議員, 2016年4月1日 - 2018年3月31日
- 教育研究評議会評議員, 2018年4月1日 - 2020年3月31日
- 教育研究評議会評議員, 2020年4月1日 - 2022年3月31日
- 教育研究評議会評議員, 2022年4月1日 - 2024年3月31日
- 歯学部長, 2018年4月1日 - 2020年3月31日
- 歯学部長, 2020年4月1日 - 2022年3月31日
- 歯学部副学部長, 2014年4月1日 - 2016年3月31日
- 歯学部副学部長, 2016年4月1日 - 2018年3月31日
- 歯学部副学部長, 2022年4月1日 - 2024年3月31日
- 大学院歯学院長, 2018年4月1日 - 2020年3月31日
- 大学院歯学院長, 2020年4月1日 - 2022年3月31日
- 大学院歯学院副学院長, 2017年4月1日 - 2018年3月31日
- 大学院歯学院副学院長, 2022年4月1日 - 2024年3月31日
- 大学院歯学研究院長, 2018年4月1日 - 2020年3月31日
- 大学院歯学研究院長, 2020年4月1日 - 2022年3月31日
- 大学院歯学研究院副研究院長, 2017年4月1日 - 2018年3月31日
- 大学院歯学研究院副研究院長, 2022年4月1日 - 2024年3月31日
- 大学院歯学研究科副研究科長, 2014年4月1日 - 2016年3月31日
- 大学院歯学研究科副研究科長, 2016年4月1日 - 2017年3月31日
■Research activity information
Papers
- Promoting Dentin Bridge Formation Through N-Acetyl-L-Cysteine Application in Rat Molar Pulpotomy: An Experimental Study
Kota Takagi, Koichi Nakamura, Yoshitaka Yoshimura, Yasutaka Yawaka
Journal of Functional Biomaterials, 16, 4, 117, 117, MDPI AG, 27 Mar. 2025
Scientific journal, Pulpotomy is performed when tooth decay reaches the dental pulp or when the crown is fractured due to trauma. Mineral trioxide aggregate (MTA) is commonly used in pulpotomy, but its prognosis can be variable. N-acetyl-L-cysteine (NAC), an antioxidant amino acid, has garnered attention due to its potential benefits. This study aimed to investigate the effects of MTA and NAC on pulpotomy outcomes. We used Sprague Dawley rat maxillary molars to perform pulpotomy and employed Superbond C&B, MTA, and MTA mixed with NAC (MTA–NAC) for pulp capping. We obtained tissue sections 3 and 7 days postpulpotomy, conducting histological analysis by examining the morphology of pulp tissue and assessing dentin sialophosphoprotein (DSPP) and osteopontin expression levels. At 3 days postpulpotomy, MTA and MTA–NAC reduced the inflammatory response. At 7 days postpulpotomy, dentin bridge formation was observed following MTA–NAC application, and although MTA resulted in DSPP- and osteopontin-positive areas, these areas were more extensive following MTA–NAC application. Given that adding NAC to MTA enhanced dentin bridge formation, MTA–NAC appears to be a superior option for pulp capping. - 症候性全般てんかんの女児にみられた原因不明の歯肉増殖により乳歯の萠出に障害をきたした症例(第1報)
中村 光一, 趙 継美, 八若 保孝
障害者歯科, 45, 3, 159, 164, (公社)日本障害者歯科学会, Oct. 2024
Japanese - Enhanced phagocytosis associated with multinucleated microglia via Pyk2 inhibition in an acute β-amyloid infusion model
Ji-Won Lee, Kaito Mizuno, Haruhisa Watanabe, In-Hee Lee, Takuya Tsumita, Kyoko Hida, Yasutaka Yawaka, Yoshimasa Kitagawa, Akira Hasebe, Tadahiro Iimura, Sek Won Kong
Journal of Neuroinflammation, 21, 1, Springer Science and Business Media LLC, 06 Aug. 2024, [Peer-reviewed]
Scientific journal - Oral findings in a patient with Alexander disease: A case report
Musashi Sawada, Chihiro Takasaki, Satoshi Tokura, Yasutaka Yawaka
Pediatric Dental Journal, Elsevier BV, Jul. 2024
Scientific journal - 亜鉛ガラス含有グラスアイオノマーセントのエナメル質に対する効果
鈴木 翔斗, 高木 康多, 中村 光一, 八若 保孝
小児歯科学雑誌, 62, 大会抄録号, 157, 157, (公社)日本小児歯科学会, Apr. 2024
Japanese - 生活歯髄切断材料における抗酸化アミノ酸の応用
高木 康多, 中村 光一, 高濱 暁, 鈴木 翔斗, 八若 保孝
小児歯科学雑誌, 62, 地方会抄録号, 3, 3, (公社)日本小児歯科学会, Feb. 2024
Japanese - 当大学病院小児・障害者歯科外来における2016年から5年間の新規来院患者の実態調査
趙 継美, 高木 康多, 高橋 静香, 竹渕 塁, 中村 光一, 八若 保孝
小児歯科学雑誌, 61, 3, 110, 116, (公社)日本小児歯科学会, Nov. 2023
Japanese - スペシャルオリンピックス日本・北海道EKSDAY2022ヘルシー・アスリート・プログラム スペシャルスマイルズの活動概要と健診結果
中村 光一, 鈴木 翔斗, 高木 康多, 那須 結菜, 三浦 真理, 村井 裕子, 日原 加代, 小森 さやか, 石川 佳恵, 島田 裟彩, 江草 正彦, 小笠原 正, 八若 保孝
日本障害者歯科学会総会および学術大会プログラム・抄録集, 40回, 180, 180, (公社)日本障害者歯科学会, Oct. 2023
Japanese - Incremental lines in human cellular cementum: A histological study.
Shizuka Takahashi, Tsuneyuki Yamamoto, Tomomi Takahashi, Yasutaka Yawaka
Journal of oral biosciences, 65, 1, 55, 61, Mar. 2023, [International Magazine]
English, Scientific journal, OBJECTIVES: Human cellular cementum has incremental lines that demarcate individual cementum lamellae. The structural and functional details of the lines remain poorly understood. This study was designed to examine human cellular cementum using light microscopy, scanning electron microscopy, and contact microradiography and to elucidate the ultrastructure of incremental lines and their significance in cellular cementogenesis. METHODS: Longitudinal paraffin and ground sections of human mandibular molars were prepared. Paraffin sections were stained with hematoxylin, or hematoxylin and eosin, or impregnated with silver. Hematoxylin-stained sections were observed via scanning electron microscopy using NaOH maceration. Silver-impregnated sections were further stained with hematoxylin. Hematoxylin-stained ground sections were examined using contact microradiography. RESULTS: The incremental lines were found to be collagen fibril-poor layers. The outer area of each cementum lamella consisted of highly mineralized fibrils involved in constructing an alternating lamellar structure, whereas the inner area consisted of irregularly arranged, less highly mineralized, fibrils. The incremental lines corresponded with the innermost sites of the inner area. CONCLUSIONS: Based on the obtained findings, we suggest that cellular cementogenesis progresses as follows. (1) Cementoblasts alternate between low-to high-activity states. (2) In the earliest low-activity stage, cementoblasts generate poorly mineralized, fibril-poor, incremental lines. (3) As cementoblasts recover activity, fibril-organization and mineralization advance in the cementum. (4) In the high-activity stage, cementoblasts reach full activity and construct the highly mineralized, alternating lamellar structure. (5) Cementoblasts revert back to the low-activity stage. (6) The above processes are repeated, thus, alternately generating the incremental lines and cementum lamellae. - Impacted mandibular primary second molar: A case report
Yasutaka Yawaka, Kyoko Shinoguchi, Makoto Fujii, Shohei Oshima
Pediatric Dental Journal, 32, 2, 123, 128, Aug. 2022, [Peer-reviewed], [Lead author]
English, Scientific journal - A rare case of multiple brain abscesses caused by apical periodontitis of deciduous teeth in congenital heart disease: a case report.
Shizuka Takahashi, Hisato Segoe, Takashi Kikuiri, Yuji Maruo, Tomonobu Sato, Yutaka Watanabe, Zhao Jimei, Yoshitaka Yoshimura, Misa Ishiyama, Atsuhito Takeda, Yasutaka Yawaka, Tetsuo Shirakawa
BMC oral health, 22, 1, 261, 261, 28 Jun. 2022, [Peer-reviewed], [International Magazine]
English, Scientific journal, BACKGROUND: A brain abscess is a focal infection in which abscesses form in the brain. A brain abscess is a rare but fatal disease when rupture occurs into the ventricles. We report a case of multiple brain abscesses caused by a hematogenous infection from the apical periodontitis of deciduous teeth. CASE PRESENTATION: The patient was a 7-years and 8-months-old male with congenital heart disease. The patient sought medical attention due to fever and headache, for which he was started on three antibiotics with a diagnosis of multiple brain abscesses. Given that apical periodontitis of deciduous teeth was strongly suspected as the source of the brain abscess, the deciduous teeth were extracted. Immediately after deciduous teeth extraction, the patient's headache and neurological symptoms disappeared. CONCLUSIONS: After teeth extraction, a clear shrinkage of the brain abscess was observed, and the patient was discharged from the hospital. - Adhesion in pediatric dentistry
Yasutaka Yawaka
日本歯科理工学会誌, 41, 1, 52, 57, 2022, [Peer-reviewed], [Invited], [Lead author]
Japanese, Scientific journal - Occurrence of subcutaneous emphysema during a caries filling procedure: A case report
Takashi Kikuiri, Kureha Saito, Airi Iida, Yoshitaka Yoshimura, Yasutaka Yawaka, Tetsuo Shirakawa
Pediatric Dental Journal, 2022, [Peer-reviewed]
English, Scientific journal - Bone resorption improvement by conditioned medium of stem cells from human exfoliated deciduous teeth in ovariectomized mice.
AYAKO MAEDA, TAKASHI KIKUIRI, YOSHITAKA YOSHIMURA, YASUTAKA YAWAKA, TETSUO SHIRAKAWA
EXPERIMENTAL AND THERAPEUTIC MEDICINE, 23, 4, Spandidos Publications, 2022, [Peer-reviewed]
English, Scientific journal - N-acetylcysteine attenuates PGE2 and ROS production stimulated by 4-META/MMA-based resin in murine osteoblastic cells.
Koichi Nakamura, Hajime Minamikawa, Shizuka Takahashi, Yoshitaka Yoshimura, Yasutaka Yawaka
Dental materials journal, 40, 3, 808, 812, 29 May 2021, [Domestic magazines]
English, Scientific journal, This study examined the effects of N-acetylcysteine (NAC) on the inflammatory reactions of murine osteoblastic cells cultured on the 4-methacryloxyethyl trimellitate anhydride/methyl methacrylate (4-META/MMA)-based resin. Superbond C&B (SB) was used as the 4-META/MMA-based resin and placed in a 48-well cell culture plate. The cells were cultured in αMEM (control) as well as on SB and SB in αMEM with NAC (SB+NAC). They were examined using the WST-1 proliferation assay, real-time PCR, enzyme-linked immunosorbent assay (ELISA), intracellular reactive oxygen species (ROS) measurements, and cellular glutathione (GSH) detection. COX-2 and IL-6 gene expressions were upregulated in SB; however, they were suppressed by NAC. Furthermore, PGE2 production in the culture medium was increased in SB, whereas NAC decreased the PGE2 production. NAC lowered the ROS level in the culture medium and significantly increased the intracellular GSH level. The present in vitro study demonstrated that NAC might be effective for dental material detoxification. - Evaluation of maturation of bone and teeth during the early stage of school age and the relationship between chronological age, bone age, and dental age
Mayuko Kato, Ayako Maeda, Mitsuhiko Nishimi, Kanji Iwadera, Nobuki Iwadera, Toshihiro Yoshihara, Yasutaka Yawaka
日本小児歯科学雑誌, 59, 2, 71, 79, May 2021, [Peer-reviewed], [Last author]
Japanese, Scientific journal - National investigation on home visit dental treatment for children in Japan.
Takai Rihito, Tamura Humiyo, Kikutani Takeshi, Ogata Kiyokazu, Oshima Shohei, Yawaka Yasutaka
Disability and Oral Health, 42, 1, 91, 98, Feb. 2021, [Peer-reviewed], [Last author]
Japanese, Scientific journal - A survey of the state of new patients at the Clinical Department of Dentistry for Children and Disabled Persons of a University Dental Hospital over the past six years
Ayako Maeda, Akina Hisada, Megumi Hoshino, Nobuki Iwadera, Risa Taneichi, Kouichi Nakamura, Chihiro Takasaki, Yasutaka Yawaka
日本小児歯科学雑誌, 58, 3, 149, 156, Oct. 2020, [Peer-reviewed], [Last author]
Japanese, Scientific journal - Effects of N-acetylcysteine on root resorption after tooth replantation
Mitsuhiko Nishimi, Koichi Nakamura, Akina Hisada, Kazuki Endo, Shuya Ushimura, Yoshitaka Yoshimura, Yasutaka Yawaka
Pediatric Dental Journal, 30, 1, 72, 79, Elsevier BV, Jun. 2020, [Peer-reviewed], [Last author]
English, Scientific journal - 4-META/MMA-TBBレジンに惹起された炎症に対するN-acetyl cysteineの効果
高橋 静香, 中村 光一, 八若 保孝
小児歯科学雑誌, 58, 大会抄録(誌上開催)号, 123, 123, (公社)日本小児歯科学会, Apr. 2020
Japanese - N-アセチルシステインによる歯根吸収抑制メカニズムの解析
西見 光彦, 中村 光一, 久田 明奈, 八若 保孝
小児歯科学雑誌, 58, 大会抄録(誌上開催)号, 124, 124, (公社)日本小児歯科学会, Apr. 2020
Japanese - 当大学病院小児・障害者歯科外来における最近5年間の初診患者の実態調査
趙 継美, 高木 康多, 高橋 静香, 中村 光一, 八若 保孝
小児歯科学雑誌, 58, 大会抄録(誌上開催)号, 227, 227, (公社)日本小児歯科学会, Apr. 2020
Japanese - 当大学病院小児・障害者歯科外来において来院回数が一回のみである初診患者の実態調査
高木 康多, 趙 継美, 高橋 静香, 中村 光一, 八若 保孝
小児歯科学雑誌, 58, 大会抄録(誌上開催)号, 231, 231, (公社)日本小児歯科学会, Apr. 2020
Japanese - 医科および歯科訪問診療を受ける医療的ケア児における往診と入院の実態
高井 理人, 大島 昇平, 八若 保孝
障害者歯科, 40, 3, 322, 322, (公社)日本障害者歯科学会, Sep. 2019
Japanese - Effects of root canal irrigations on intracanal medication with calcium hydroxide effects in root external resorption models
Akina Hisada, Koichi Nakamura, Yuki Toyota, Ayako Maeda, Toshihiro Yoshihara, Yasutaka Yawaka
Pediatric Dental Journal, 29, 1, 17, 22, Elsevier Ltd, 01 Apr. 2019
English, Scientific journal - Daily life habits associated with eveningness lead to a higher prevalence of dental caries in children
Shinya Nishide, Toshihiro Yoshihara, Hirohisa Hongou, Takeshi Kanehira, Yasutaka Yawaka
Journal of Dental Sciences, 14, 302, 308, Apr. 2019, [Last author]
English, Scientific journal - Immunolocalization of podoplanin/E11/gp38, CD44, and endomucin in the odontoblastic cell layer of murine tooth germs
Naznin K, Hasegawa T, Nagai T, Yamamoto T, Miyamoto-Takasaki Y, Hongo H, Abe M, Haraguchi M, Yamamoto T, Yimin Qiu Z, Sasaki M, Kuroshima S, Ohshima H, Freitas PHL, Li M, Yawaka Y, Amizuka N
Biomed Res, 40, 4, 133, 143, 2019, [Peer-reviewed]
English, Scientific journal - Patients with SATB2-associated syndrome exhibiting multiple odontomas.
Kikuiri T, Mishima H, Imura H, Suzuki S, Matsuzawa Y, Nakamura T, Fukumoto S, Yoshimura Y, Watanabe S, Kinoshita A, Yamada T, Shindoh M, Sugita Y, Maeda H, Yawaka Y, Mikoya T, Natsume N, Yoshiura KI
Am J Med Genet A., 176, 12, 2614, 2622, Dec. 2018, [Peer-reviewed]
Scientific journal - Oral findings in a patient with megacystis microcolon intestinal syndrome: A case report.
Chihiro Takasaki, Toshihiro Yoshihara, Yasutaka Yawaka
Pediatr Dent J, 28, 2, 57, 61, Aug. 2018, [Peer-reviewed]
English, Scientific journal - Calcium Charge and Release of Conventional Glass-Ionomer Cement Containing Nanoporous Silica.
Nakamura K, Abe S, Minamikawa H, Yawaka Y
Materials (Basel, Switzerland), 11, 8, Jul. 2018, [Peer-reviewed] - 日本小児歯科学会主催教育ワークショップの実施 大学間のバリエーションの把握
八若 保孝, 内川 喜盛, 香西 克之, 飯沼 光生, 早崎 治明, 清水 武彦, 佐藤 昌史, 中村 光一, 木本 茂成
日本歯科医学教育学会総会・学術大会プログラム・抄録集, 37回, 126, 126, (一社)日本歯科医学教育学会, Jul. 2018
Japanese - Effectiveness of wiping during oral care by guardians of children with severe motor and intellectual disabilities at home
Takai Rihito, Oshima Shohei, Nakamura Koichi, Yawaka Yasutaka
Journal of the Japanese Society for Disability and Oral Health, 39, 1, 1, 7, The Japanese Society for Disability and Oral Health, Feb. 2018, [Last author]
Japanese, Scientific journal,Purpose:To clarify the effectiveness of wiping during oral care by guardians at home, and factors associated with salivary bacterial count.
Method:The participants were 20 children with severe motor and intellectual disabilities (SMID) (mean age 5.5±3.8 years old) requiring both mechanical ventilator and tube-feeding. The survey was conducted during home-visit dental treatment. Guardians were instructed to do oral care (brushing their children's teeth for 2 minutes and wiping the inside of the oral cavity with gauze). They were taught how to wipe before oral care. Suction during brushing was carried out in case guardians performed brushing on a daily basis. The saliva was taken from the floor of the mouth, and the number of bacteria in saliva was measured by a bacteria detection apparatus (Panasonic Healthcare Co., Ltd.). Collection and measurement were conducted before brushing, after brushing, and after wiping. The correlations between the number of bacteria taken before brushing and information regarding patient characteristics such as method of feeding, use of mechanical ventilator, existence of tracheostomy, existence of continuous suction, and existence of swallowing were examined statistically.
Results:The number of bacteria in saliva decreased significantly from before and after brushing to after wiping. There was no significant correlation between the existence of suction during brushing and variation of salivary bacterial count before and after brushing. The independent variables shown by univariate analysis to have a significant relationship with salivary bacterial count before brushing were use of mechanical ventilator, existence of tracheostomy, and existence of swallowing. Multiple regression analysis identified existence of swallowing as an independent associated factor for salivary bacterial count.
Conclusion:Wiping was an effective method to decrease bacteria after brushing. Children who do not swallow had larger numbers of bacteria in saliva before brushing. These findings indicated that it is important for children who do not swallow to have their oral cavity wiped after tooth-brushing.
- Estimation of controlled drug-release behavior of nano-porous silica micro particles and their biocompatibility
Eri Seitoku, Yuko Era, Ko Nakanishi, Yosuke Bando, Shinichi Kakuda, Koichi Nakamura, Teruo Kusaka, Shigeaki Abe, Mariko Nakamura, Yasutaka Yawaka, Junichiro Iida, Yasuhiro Yoshida, Hidehiko Sano
Nano Biomedicine, 9, 2, 112, 116, National Institute of Informatics, 2018, [Peer-reviewed]
English, Scientific journal - Root canal treatment of traumatized permanent teeth with external root resorption
Yasutaka Yawaka, Yuki Toyota, Akina Hisada, Ayako Maeda, Shohei Inoue, Toshihiro Yoshihara
Hokkaido Journal of Dental Science, 38, Special issue, 122, 129, 北海道歯学会, Sep. 2017, [Lead author]
English, Scientific journal, External root resorption is an important challenge in the preservation of traumatized teeth. External root resorption is observed in cases of replanted teeth from dental trauma. Root canal dressing containing calcium hydroxide (Ca(OH)2) is one recommended clinical approach for external root resorption treatment. However, complete control of external resorption may not be possible due to certain factors, such as the smear layer, which is formed by reaming and filing during root canal treatments. The smear layer plugs dentinal tubules and inhibits the effects of Ca(OH)2 as a root canal dressing material. Our study showed that root canal irrigation with ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl) with an ultrasonic device is the most effective method to remove the smear layer. Additionally, we observed an alkaline environment at the outer root surface due to ion diffusion from Ca(OH)2 following this treatment. As a result, the combined use of EDTA and NaOCl with an ultrasonic device for root canal irrigation led to good control of external root resorption. - Effectiveness of Rubrics and Reflection Process Introduced to Basic Dental Practice Education for Pediatric Dentistry
Chihiro Takasaki, Yoshiaki Sato, Yoshiaki Chihiro Takasaki, Nobuki Iwadera, Risa Taneichi, Yasutaka Yawaka
The Japanese Journal of Pediatric Dentistry, 55, 3, 364, 374, Jun. 2017, [Peer-reviewed]
Japanese, Scientific journal - 小児歯科学臨床基礎実習に試行導入したルーブリックと振り返りに対する有効性の検討
高崎千尋, 佐藤嘉晃, 岩寺信喜, 種市梨紗, 八若保孝
小児歯科学雑誌, 55, 3, 364, 374, Jun. 2017, [Peer-reviewed]
Japanese, Scientific journal - 当院で訪問歯科診療を実施した在宅重症心身障害児の実態
高井 理人, 大島 昇平, 八若 保孝
小児歯科学雑誌, 55, 2, 241, 241, (公社)日本小児歯科学会, Apr. 2017
Japanese - Removal of smear layer by various root canal irrigations in primary teeth
Yuki Toyota, Toshihiro Yoshihara, Akina Hisada, Yasutaka Yawaka
Pediatric Dental Journal, 27, 1, 8, 13, Elsevier Ltd, 01 Apr. 2017, [Peer-reviewed]
English, Scientific journal - Effect of fluoride-releasing fissure sealants on enamel demineralization
Koichi Nakamura, Shigeaki Abe, Hajime Minamikawa, Yasutaka Yawaka
Pediatric Dental Journal, 27, 1, 56, 64, Elsevier Ltd, 01 Apr. 2017, [Peer-reviewed]
English, Scientific journal - Charge and controlled release of epigallocatechin gallate by glass ionomer cement containing nanoporous silica particles.
Nakamura K, Nakanishi K, Bando Y, Hasebe A, Hyono A, Abe S, Shibata K, Yoshida Y, Iida J, Yawaka Y
Nano Biomedicine, 9, 1, 29, 34, Jan. 2017, [Peer-reviewed]
English, Scientific journal - 超音波スケーラーを用いたスケーリング時における注水液の回収率に関する検討
高井 理人, 中村 光一, 八若 保孝
障害者歯科, 37, 3, 265, 265, (公社)日本障害者歯科学会, Sep. 2016
Japanese - 在宅人工呼吸器を使用する重症心身障害児者における歯科受診状況および訪問歯科診療のニーズ
高井 理人, 中村 光一, 八若 保孝
障害者歯科, 37, 3, 275, 275, (公社)日本障害者歯科学会, Sep. 2016
Japanese - Assessment of the inhibitory effects of fissure sealants on the demineralization of primary teeth using an automatic pH-cycling system
Shuya Ushimura, Koichi Nakamura, Yasuhiro Matsuda, Hajime Minamikawa, Shigeaki Abe, Yasutaka Yawaka
DENTAL MATERIALS JOURNAL, 35, 2, 316, 324, Apr. 2016, [Peer-reviewed]
English, Scientific journal - Estimation of Biocompatibility of Nano-Sized Ceramic Particles with Osteoblasts, Osteosarcomas and Hepatocytes by Static and Time-Lapse Observation
Abe S, Seitoku E, Iwadera N, Hamba Y, Yamagata S, Akasaka T, Kusaka T, Inoue S, Yawaka Y, Iida J, Sano H, Yonezawa T, Yoshida Y
J Biomed Nanotechnol., 12, 3, 472, 480, Mar. 2016, [Peer-reviewed]
English, Scientific journal - P-1-E12 在宅重症心身障害児者の唾液中細菌数に関連する因子についての検討
高井 理人, 工藤 裕子, 中村 光一, 八若 保孝, 土畠 智幸
日本重症心身障害学会誌, 41, 2, 248, 248, 日本重症心身障害学会, 2016
Japanese, 緒言重症心身障害児者(以下、重症児者)では合併症としての誤嚥性肺炎がしばしば問題となる。また、口腔内細菌が起炎菌となることが知られており、口腔ケアの重要性が周知されてきた。今回、在宅重症児者の唾液中細菌数を調査し、細菌数に影響を与える因子について検討したので報告する。方法当院患者のうち、訪問歯科診療を受けている在宅重症児者30名(1歳〜40歳、平均年齢13.7±9.7歳)を対象とし、調査期間は平成27年11月から平成28年1月までの3カ月間とした。調査は居宅訪問中(10時〜16時)に行い、舌下部に滅菌綿棒を10秒間浸して唾液を採取し、卓上細菌数測定装置(パナソニックヘルスケア社製)を用いて唾液中細菌数を測定した。また、全身状態(経管栄養、気管切開、人工呼吸器、唾液嚥下の有無)、口腔内状況(歯石、舌苔、齲蝕の有無)について調査し、それぞれの項目と唾液中細菌数との関連を統計学的に検討した。結果唾液中細菌数と有意な正の関連を示した項目は、気管切開「有」(p=0.027)、唾液嚥下「無」(p=0.010)、舌苔「有」(p=0.028)であった。考察唾液嚥下を認めない者の口腔内は、嚥下反射の低下により口腔内に唾液が長時間貯留するため口腔内細菌が増殖しやすい環境であると考えられる。また、気管切開の影響により嚥下運動が困難になっている可能性がある。舌苔の付着が多い者は、舌の運動性が低いため自浄作用が低下していると考えられ、口腔機能の低下が唾液中細菌数に影響を与えていると思われた。結語在宅重症児者において、嚥下機能や口腔機能が低下していると唾液中細菌数が多い。今後、この結果をもとに重症児者に対する誤嚥性肺炎の予防方法について検討する必要がある。 - 在宅人口呼吸器を使用する重症心身障害児に対する訪問歯科診療についての検討
高井理人, 大島昇平, 中村光一, 八若保孝
小児歯科学雑誌, 55, 3, 382, 389, 2016, [Peer-reviewed]
Japanese, Scientific journal - Activation of inflammasome by Aggregatibacter actinomycetemcomitans
阿部亜美, 佐伯歩, 長谷部晃, 原博志, 八若保孝, 柴田健一郎
北海道歯学雑誌, 35, 2, 123, 132, 北海道歯学会, 15 Mar. 2015
Japanese - Disease specificity of anti-tryptophan hydroxylase-1 and anti-AIE-75 autoantibodies in APECED and IPEX syndrome
Natsuko Chida, Ichiro Kobayashi, Shunichiro Takezaki, Masahiro Ueki, Yasuhiro Yamazaki, Silvia Garelli, Riccardo Scarpa, Reiko Horikawa, Masafumi Yamada, Corrado Betterle, Luigi D. Notarangelo, Yasutaka Yawaka, Tadashi Ariga
CLINICAL IMMUNOLOGY, 156, 1, 36, 42, Jan. 2015, [Peer-reviewed]
English, Scientific journal - 歯科診療に不協力な小児や障害者に対する歯科診療時の自律神経機能の評価方法についての検討
星野 恵, 大島昇平, 種市梨紗, 北村かおる, 下地伸司, 川浪雅光, 八若保孝
小児歯誌, 53, 3, 390, 398, 2015, [Peer-reviewed]
Japanese, Scientific journal - 障害者に対する歯科診療が自律神経機能に及ぼす影響 -心拍変動解析を用いた評価-
星野 恵, 大島昇平, 種市梨紗, 北村かおる, 下地伸司, 川浪雅光, 八若保孝
北海道歯誌, 36, 1, 4, 13, 2015, [Peer-reviewed]
Japanese - 大学病院受診患者における喪失歯を参考とした長期的口腔管理に対する検討 障害者入所施設入居者について
野島 靖子, 牛村 秀耶, 中村 光一, 大島 昇平, 八若 保孝, 森 貴幸, 江草 正彦
障害者歯科, 34, 3, 386, 386, (一社)日本障害者歯科学会, Sep. 2013
Japanese - Differential effects of repeated immobilization stress in early vs. late postnatal period on stress-induced corticosterone response in adult rats
Yoshihara Toshihiro, Yawaka Yasutaka
Neuroscience Letters, 534, 30, 34, Elsevier, 08 Feb. 2013
English, This study was performed in order to determine how immobilization stress in the early postnatal period or in the late postnatal period affects growth in the developing rat, and the response of the hypothalamus-pituitary-adrenocortical (HPA) axis in adult rats subjected to subsequent novel stresses. In addition, the effects of maternal deprivation (MD) within the same period of exposure to immobilization stress were also examined. We used two different types of immobilization stress and two different types of MD: immobilization stress for 30 min per day from postnatal day 7 (P7) to P13 (IS-E group); immobilization stress for 30 min from P15 to P21 (IS-L group); MD for 30 min per day from P7 to P13 (MD-E group); and MD for 30 min per day from P15 to P21 (MD-L group). The IS-E group showed a significant reduction in body weight that was maintained until at least P40 when compared with the control group. On the other hand, the IS-L group showed a significant reduction in body weight at only postnatal day (P) 20 when compared with the control group. Furthermore, the IS-E group showed a larger HPA response to novel stress than the IS-L and control groups in adulthood. The MD-E group showed a significant reduction in body weight that was maintained until at least P20 when compared with the control group, but did not show a larger HPA response to novel stress, except at T30 (30 min after exposure to novel stress) than the control group in adulthood. The MD-L group did not show a significant reduction in body weight or increased HPA response when compared with control rats. These results suggest that repeated immobilization stress, but not MD, in the early postnatal period induces long-term effects on growth and HPA response to novel stress in adulthood. (C) 2012 Elsevier Ireland Ltd. All rights reserved. - Biocompatibility and biodistribution of several nano-sized ceramics particles
Shigeaki Abe, Yusaku Hamba, Nobuki Iwadera, Tsukasa Akasaka, Shuichi Yamagata, Yasutaka Yawaka, Junichiro Iida, Motohiro Uo, Tetsu Yonezawa, Fumio Watari
BIOCERAMICS 24, 529-530, 625, +, 2013, [Peer-reviewed]
English, International conference proceedings - Influence of micro-/nano- particles on osteoblast-like cells: A static and time lapse observation
Nobuki Iwadera, Shigeaki Abe, Tsukasa Akasaka, Yasutaka Yawaka, Fumio Watari
BIOCERAMICS 24, 529-530, 374, +, 2013, [Peer-reviewed]
English, International conference proceedings - In situ observation of dynamic response behavior of cells exposed to micro/nano particles by time lapse observation
Nobuki Iwadera, Yasutaka Yawaka, Fumio Watari
Nano Biomedicine, 4, 2, 57, 65, National Institute of Informatics, 2012
English, Scientific journal - Biodistribution of Aqueous Suspensions of Carbon Nanotubes in Mice and Their Biocompatibility
Shigeaki Abe, Sachiko Itoh, Daisuke Hayashi, Toshihisa Kobayashi, Takayuki Kiba, Tsukasa Akasaka, Motohiro Uo, Yasutaka Yawaka, Shin-Ichiro Sato, Fumio Watari, Tomoya Takada
Journal of Nanoscience and Nanotechnology, 12, 1, 700, 706, American Scientific Publishers, 01 Jan. 2012, [International Magazine]
English, Scientific journal, In this study, we prepared two-types of water-dispersible carbon nanotubes (CNTs) and investigated their biodistribution in mice as well as bio-/cyto-compatibility. After administration, their organs were excised at various post-injection times, then observed using both optical and transmission electron microscopy (TEM). The color of the liver and lung markedly darkened, suggesting that administered CNTs reached these organs. By TEM observation, the CNTs were found in the liver and lung. They were observed even in the kidney and spleen, though their distributions in those organs were very low compared with that in liver and lung. Therefore, most of the administered CNTs would be accumulated in the liver or lung. However, the time profile of the body weight of CNT-administered mice was close to that of control mice. In addition, we estimated the cytocompatibility of the water-dispersible CNTs for hepatocytes. According to a TNF-alpha assay of the cells cultured with CNTs, the expression level was almost the same as that of the control. These results suggested that the water-dispersible CNTs have good bio-/cyto-compatibility under this condition. - Lesions of the ventral ascending noradrenergic bundles decrease the stress response to occlusal disharmony in rats
Toshihiro Yoshihara, Yasutaka Yawaka
NEUROSCIENCE LETTERS, 503, 1, 43, 47, Sep. 2011, [Peer-reviewed]
English, Scientific journal - Ion release and buffering capacity of S-PRG filler-containing pit and fissure sealant in lactic acid
Ying Wang, Masayuki Kaga, Daisuke Kajiwara, Hajime Minamikawa, Shinichi Kakuda, Masanori Hashimoto, Yasutaka Yawaka
Nano Biomedicine, 3, 2, 275, 281, 2011
English, Scientific journal - Application of Imogolite, Almino-Silicate Nanotube, as Scaffold for the Mineralization of Osteoblasts
Kosuke Ishikawa, Tsukasa Akasaka, Shigeaki Abe, Yasutaka Yawaka, Masaya Suzuki, Fumio Watari
Bioceramics Development and Applications, 1, D110133, Jan. 2011, [Peer-reviewed]
English, Scientific journal - Amino acid derivative-mediated detoxification and functionalization of dual cure dental restorative material for dental pulp cell mineralization.
Minamikawa H, Yamada M, Iwasa F, Ueno T, Deyama Y, Suzuki K, Yawaka Y, Ogawa T
Biomaterials, 31, 28, 7213, 7225, Oct. 2010, [Peer-reviewed], [International Magazine]
English, Scientific journal, Current dental restorative materials are only used to fill the defect of hard tissues, such as dentin and enamel, because of their cytotoxicity. Therefore, exposed dental pulp tissues in deep cavities must be first covered by a pulp capping material like calcium hydroxide to form a layer of mineralized tissue. However, this tissue mineralization is based on pathological reaction and triggers long-lasting inflammation, often causing clinical problems. This study tested the ability of N-acetyl cysteine (NAC), amino acid derivative, to reduce cytotoxicity and induce mineralized tissue conductivity in resin-modified glass ionomer (RMGI), a widely used dental restorative material having dual cure mechanism. Rat dental pulp cells were cultured on untreated or NAC-supplemented RMGI. NAC supplementation substantially increased the percentage of viable cells from 46.7 to 73.3% after 24-h incubation. Cell attachment, spreading, proliferative activity, and odontoblast-related gene and protein expressions increased significantly on NAC-supplemented RMGI. The mineralization capability of cells, which was nearly suppressed on untreated RMGI, was induced on NAC-supplemented RMGI. These improved behaviors and functions of dental pulp cells on NAC-supplemented RMGI were associated with a considerable reduction in the production of intracellular reactive oxygen species and with the increased level of intracellular glutathione reserves. These results demonstrated that NAC could detoxify and functionalize RMGIs via two different mechanisms involving in situ material detoxification and antioxidant cell protection. We believe that this study provides a new approach for developing dental restorative materials that enables mineralized tissue regeneration. - Anomaly of cervical vertebrae found on orthodontic examination: 8-year-old boy with cleft lip and palate diagnosed with Klippel-Feil syndrome
Toshihiro Yoshihara, Junichi Suzuki, Yasutaka Yawaka
ANGLE ORTHODONTIST, 80, 5, 975, 980, Sep. 2010, [Peer-reviewed]
English, Scientific journal - Osteoblastic cellular responses to aluminosilicate nanotubes, imogolite using Saos-2 and MC3T3-E1 cells
Kosuke Ishikawa, Shigeaki Abe, Yasutaka Yawaka, Masaya Suzuki, Fumio Watari
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 118, 1378, 516, 520, Jun. 2010, [Peer-reviewed]
English, Scientific journal - Highly sensitive detection and quantitative analysis of ultra low concentration of carbon nanotubes by absorptiometric method
Sachiko Itoh, Yasutaka Yawaka, Fumio Watari
Nano Biomedicine, 2, 2, 130, 138, 2010
English, Scientific journal - Cytotoxicity of strengthened glass-ionomer cement by compounding short fibers with CaO-P2O5-SiO2-Al2O 3 glass
Masayuki Kaga, Masahiro Kobayashi, Kosuke Ishikawa, Hajime Minamikawa, Yasutaka Yawaka, Fumio Watari
Nano Biomedicine, 2, 1, 23, 30, 2010
English, Scientific journal - Regulation of microRNA expression by bone morphogenetic protein-2
Mari M. Sato, Yasutaka Yawaka, Masato Tamura
INTERFACE ORAL HEALTH SCIENCE 2009, 158, 160, 2010, [Peer-reviewed]
English, International conference proceedings - Various nanotube scaffolds for cell proliferation
F. Watari, T. Akasaka, K. Ishikawa, M. Matsuoka, E. Hirata, N. Terada, A. Yokoyama, M. Uo, S. Itoh, Y. Yawaka, M. Suzuki, N. Takashi, Y. Totsuka, Y. Kitagawa, S. Abe, I. D. Rosca, Y. Kuboki, Y. Bando
Materials Science Forum, 631-632, 181, 186, 2010
International conference proceedings - High Functional Expression of Osteoblasts on Imogolite, Aluminosilicate Nanotubes
Ishikawa K, Akasaka T, Yawaka Y, Watari F
J Biomed Nanotechnol., 6, 1, 59, 65, Jan. 2010, [Peer-reviewed]
English, Scientific journal - Present Situation and Possibility of Root Canal Treatments in Primary Teeth
YAWAKA Yasutaka
The Japanese Journal of Pediatric Dentistry, 47, 5, 710, 718, Japanese Society of Pediatric Dentistry, 25 Dec. 2009
Japanese, In the root canal treatments of primary teeth, a good prognosis can be acquired by the controls of inflammation and root resorption. However, on account of the complicated root canal forms in pri mary teeth and physiological root resorption with exchange to permanent successors, there are some cases in which the ideal treatments do not become possible. In the current stage, it is important to effectively remove bacterial bio-films in root canals and smear layers with reaming and filing on root canal walls. Root canal irrigation with sodium hypochlorite with ultra sonic and/or EDTA with ultra sonic can remove bio-films and smear layers on the root canal walls. By means of irrigation, we can sufficiently utilize the effects of calcium hydroxide and other root canal medications. And the result,the prognosis of the root canal treatments seems to become good. In addition, our efforts are necessary for the development and discovery of good methods in root canal treatments including the root repair mechanism with cementum deposition of primary teeth. - Occlusal disharmony increases stress response in rats
Toshihiro Yoshihara, Risa Taneichi, Yasutaka Yawaka
NEUROSCIENCE LETTERS, 452, 2, 181, 184, Mar. 2009, [Peer-reviewed]
English, Scientific journal - In situ observation of dynamic behavior of liver cells to carbon nanotubes and analysis of cell functions
Sachiko Itoh, Toshio Taira, Yasutaka Yawaka, Fumio Watari
Nano Biomedicine, 1, 2, 95, 108, 2009
English, Scientific journal - Visualization of invasion into the body and internal diffusion of nanoparticles
F. Watari, S. Abe, I. D. Rosca, A. Yokoyama, M. Uo, T. Akasaka, N. Takashi, Y. Totsuka, E. Hirata, M. Matsuoka, K. Ishikawa, S. Itoh, Y. Yawaka
BIOCERAMICS 21, 396-398, 569, 572, 2009, [Peer-reviewed]
English, International conference proceedings - Crystal growth by fluoridated adhesive resins
Masanori Hashimoto, Kouichi Nakamura, Masayuki Kaga, Yasutaka Yawaka
DENTAL MATERIALS, 24, 4, 457, 463, Apr. 2008, [Peer-reviewed]
English, Scientific journal - セルフエッチングシステムにおける溶媒が象牙質接着界面に及ぼす影響
吉田 英史, 宇野 滋, 野田坂 佳伸, 加我 正行, 八若 保孝, 平野 進
歯科材料・器械, 26, 2, 229, 229, (一社)日本歯科理工学会, Apr. 2007
Japanese - オールインワン・アドヒーシブによる象牙質接着界面の脱灰層とその微細構造
吉田 英史, 宇野 滋, 野田坂 佳伸, 加我 正行, 八若 保孝, 平野 進
歯科材料・器械, 25, 2, 107, 107, (一社)日本歯科理工学会, Apr. 2006
Japanese - 試作ペースト/ペーストタイプ修復用グラスアイオノマーセメントのコンディショナーの役割とフッ素徐放について
岩淵 英明, 八若 保孝, 吉田 英史, 藤原 百合, 加我 正行
小児歯科学雑誌, 43, 1, 126, 126, (公社)日本小児歯科学会, Mar. 2005
Japanese - NaF溶液による光硬化型グラスアイオノマーセメントシーラントのフッ素のリチャージ効果
加我 正行, 吉田 英史, 八若 保孝, 小口 春久
口腔衛生学会雑誌, 54, 2, 158, 159, (一社)日本口腔衛生学会, Apr. 2004
Japanese - 各種予防填塞材が有するフッ素の徐放とリチャージ効果
加我 正行, 中尾 加代子, 菊池 友絵, 吉田 英史, 八若 保孝, 小口 春久
小児歯科学雑誌, 41, 2, 358, 358, (公社)日本小児歯科学会, Apr. 2003
Japanese - Expression of receptor activator of NF-kappa B ligand and osteoprotegerin in culture of human periodontal ligament cells
T Hasegawa, Y Yoshimura, T Kikuiri, Y Yawaka, S Takeyama, A Matsumoto, H Oguchi, T Shirakawa
JOURNAL OF PERIODONTAL RESEARCH, 37, 6, 405, 411, Dec. 2002, [Peer-reviewed]
English, Scientific journal - 歯肉に膨隆を認めた3症例
八若 保孝, 菊地 友絵, 中尾 加代子, 福井 亜実, 小口 春久
小児歯科学雑誌, 40, 2, 412, 412, (公社)日本小児歯科学会, Apr. 2002
Japanese - 本学歯学部附属病院小児歯科外来における初診患者の実態調査 5年間(平成8〜12年度)の動態(1) 初診時について
菊地 友絵, 中尾 加代子, 弘中 祥司, 八若 保孝, 加我 正行, 小口 春久
小児歯科学雑誌, 40, 1, 207, 207, (公社)日本小児歯科学会, Mar. 2002
Japanese - 本学歯学部附属病院小児歯科外来における初診患者の実態調査 5年間(平成8〜12年度)の動態(2) その後の動向について
中尾 加代子, 菊地 友絵, 弘中 祥司, 八若 保孝, 加我 正行, 小口 春久
小児歯科学雑誌, 40, 1, 207, 207, (公社)日本小児歯科学会, Mar. 2002
Japanese - ヒト破歯細胞に関する微細形態学的研究 : 感染根管処置経験乳歯について
長内 正数, 土門 卓文, 八若 保孝, 小口 春久
小児歯科学雑誌, 37, 2, 325, 325, 一般社団法人 日本小児歯科学会, 01 Apr. 1999
Japanese - 乳歯歯根の病的吸収部位に添加されたセメント質について
八若 保孝, 長内 正数, 秋山 明美, 原田 理恵, 小口 春久
小児歯科学雑誌, 35, 2, 228, 228, 一般社団法人 日本小児歯科学会, 01 Apr. 1997
Japanese - 上顎前歯部歯槽堤に発生した先天性神経線維腫の1例
秋山 明美, 八若 保孝, 原田 理恵, 長内 正数, 雨宮 璋, 小口 春久
小児歯科学雑誌, 35, 2, 274, 274, 一般社団法人 日本小児歯科学会, 01 Apr. 1997
Japanese - Histological Study of the Invasion of Microorganisms into the Root Canal and Dentinal Tubules of Pulpless Deciduous Teeth : Transmission Electron Microscopic Observation
YAWAKA Yasutaka, TANIGUCHI Akikazu, KOJIMA Hiroshi, OGUCHI Haruhisa
The Japanese Journal of Pediatric Dentistry, 33, 3, 581, 593, The Japanese Society of Pediatric Dentistry, 25 Jun. 1995
Japanese, The root canal and intracanal wall of three deciduous teeth which were extracted due to advanced apical periodontitis and sever abnormal root resorption were examined by means of light and transmission electron microscopes.
There was a large quantity of microorganisms in the root canal and on the intracanal wall in all specimens. Invasion of microorganisms into the dentinal tubules in the coronal third in all specimens was observed, and in the middle third in two specimens. However, the apical third in all specimens showed no invasion of microorganisms into the dentinal tubules. According to our previous study and this study, therefore, it is suggested that before the microorganisms invade into the dentinal tubules, inflammation certainly breaks out and advances in the apical and furcation regions in deciduous teeth.
Very small electron-denced materials adhered irregularly on the dentinal tubule wall in the apical region. These materials were unknown, but it was thought that they were intimately related to the infection and inflammation in the apical region. Also, partial cementum-like tissue deposition on intracanal wall in the apical region showed the restration mechanism in the process of abnormal root resorption. - Histological Study of the Invasion of Microorganisms into the Dential Tubules of Pulples Deciduous Teeth : Observation under Scanning Electron Microscopy
TANIGUCHI Akikazu, YAWAKA Yasutaka, KOJIMA Hiroshi, OGUCHI Haruhisa
The Japanese Journal of Pediatric Dentistry, 33, 3, 572, 580, The Japanese Society of Pediatric Dentistry, 25 Jun. 1995
Japanese, Specimens were prepared from six deciduous molars which were extracted due to advanced periapical lesions. Localization of the microorganisms in the dential tubules of the root was investigated histologically under scanning electron microscopy.
The invasion of the microorganisms into the dentinal tubules of the root was observed in six specimens out of ten. In most cases, the invasion of the microorganisms into the dentinal tubules was observed in the coronal third especially around the entrance to the root canal. In the region of the apical third, only one specimen showed a bacterial invasion which was superficial and limited in some tubules.
These observations indicated that the invasion of the microorganisms into the dential tubules was not especially noticable in the middle or apical portions of the root of pulpless deciduous teeth. - ヒト乳歯歯根吸収面に存在する破歯細胞の微細形態学的研究
長内 正数, 八若 保孝, 脇田 稔, 小口 春久
小児歯科学雑誌, 33, 2, 261, 261, 一般社団法人 日本小児歯科学会, 01 Apr. 1995
Japanese - ヒト乳歯歯根の病的異常吸収部位に関する組織学的研究
八若 保孝, 長内 正数, 谷口 晃一, 小島 寛, 小口 春久
小児歯科学雑誌, 33, 2, 319, 319, 一般社団法人 日本小児歯科学会, 01 Apr. 1995
Japanese - ELECTRON-MICROSCOPIC AND HISTOCHEMICAL-STUDIES OF THE MONONUCLEAR ODONTOCLAST OF THE HUMAN
T DOMON, K SUGAYA, Y YAWAKA, M OSANAI, Y HANAIZUMI, S TAKAHASHI, M WAKITA
ANATOMICAL RECORD, 240, 1, 42, 51, Sep. 1994, [Peer-reviewed]
English, Scientific journal - Observation of odontoclasts in the human deciduous teeth by tartrate-resistant acid phosphatase activity.
Yawaka Yasutaka
Journal of Oral Biosciences, 35, 5, 409, 430, Japanese Association for Oral Biology, 1993
Japanese, The aim of this study is to establish an efficient method for observing the odontoclast whose location has often been difficult to find. To evaluate the feasibility of this method, sequential observations by stereoscopic, light, and transmission electron microscopies were made to detect tartrate-resistant acid phosphatase (TRACPase) activity in the healthy human transitional deciduous teeth.
The results of the stereoscopic microscopy showed that the positive TRACPase reaction which was presented as a mass of small dots was observed in the regions on the surface of resorbed root and in the pulp chamber wall. Further observations with the light and transmission electron microscopes demonstrated that the major part of the TRACPase-positive region belonged to the resorbing odontoclasts, while the remaining part belonged to the resting odontoclasts and their precursor cells. In conclusion, by using this method, it will be possible to easily localize the exact location of the odontoclast. Furthermore, it can also be expected that this method will facilitate future investigations on odontoclasts.
Other Activities and Achievements
- 口腔などにおける副作用の少ない小児がん治療の開発
趙継美, 重田馨, 中村光一, 長祐子, 八若保孝, 小児歯科学雑誌, 63, 2025 - 周術期口腔機能管理の一環として全身麻酔下での歯科治療を行った小児がんの1例
趙継美, 重田馨, 大島昇平, 長祐子, 八若保孝, 小児歯科学雑誌, 63, 2025 - Assessment of the inhibitory effects of glass-ionomer cements containing fluorozincsilicate glass
鈴木翔斗, 中村光一, 高木康多, 高橋静香, 八若保孝, 小児歯科学雑誌, 59, 2021 - 日本小児歯科学会主催CBT問題作成ワークショップの実施
八若 保孝, 内川 喜盛, 香西 克之, 早崎 治明, 飯沼 光生, 清水 武彦, 佐藤 昌史, 藤原 卓, 新谷 誠康, 中村 光一, 高崎 千尋, 木本 茂成, 日本歯科医学教育学会総会・学術大会プログラム・抄録集, 36回, 151, 151, Jul. 2017
日本歯科医学教育学会, Japanese - 日本小児歯科学会主催CBT問題作成ワークショップの実施
八若保孝, 内川喜盛, 香西克之, 早崎治明, 飯沼光生, 清水武彦, 佐藤昌史, 藤原卓, 新谷誠康, 中村光一, 高橋千尋, 木本茂成, 日本歯科医学教育学会総会・学術大会プログラム・抄録集, 36th, 151, Jul. 2017
Japanese - 小児歯科診療における内在する情動変化の評価方法に関する研究 皮膚電気活動と短時間心拍変動解析の比較
北村 かおる, 吉原 俊博, 星野 恵, 大島 昇平, 種市 梨紗, 八若 保孝, 小児歯科学雑誌, 54, 4, 450, 461, Nov. 2016, [Peer-reviewed]
(公社)日本小児歯科学会, Japanese - The distribution of number of nuclei of odontoclasts in human deciduous teeth with endodontic treatments
八木原 澄, 土門 卓文, 八若 保孝, 北海道歯学雑誌, 36, 2, 82, 89, Mar. 2016
乳歯の生理的歯根吸収は多核巨細胞である破歯細胞によって行われる.過去に著者らはヒト健全乳歯歯根を吸収する破歯細胞の核数を調査し,平均値は5.3,中央値は4であることを報告した.乳歯の歯髄処置後,象牙質に象牙芽細胞は存在せず,根管内にはアルカリ性の水酸化カルシウム製剤が充填されているため,その歯根象牙質は正常象牙質とは異なる構造を持つ.そのため, 歯髄処置経験乳歯における破歯細胞の核数を明らかにすることは,健全乳歯破歯細胞の核数と比較検討し,歯髄処置の与える影響を考える上で重要である.本研究は歯髄処置に 着目し,水酸化カルシウム系根管充填剤であるビタペックス®(ネオ製薬工業,東京)にて歯髄処置後1年から1年10か月経過後に生理的交換期に達したヒト失活乳歯歯根吸収面にみられる破歯細胞の核数の分布を連続切片による観察から検索することを目的とした. 乳歯を抜去後,固定,脱灰,パラフィン包埋後,TRAP活性陽性反応を示す20本の乳歯から乳前歯3本,乳臼歯3本の合計6本の試料を無作為抽出した.試料において4μm厚の連続切片を作製し,TRAP・メチルグリーン染色後,写真撮影を行った.連続切片による観察から歯根象牙質上に吸収窩を形成し,TRAP活性陽性を示す破歯細胞に含まれる核数を計測した.乳前歯99個,乳臼歯101個の破歯細胞の核数について検索した結果,平均値は20.8,中央値は14であった.本研究の結果とヒト健全乳歯の破歯細胞の核数の間には統計学的な有意差が認められた(p<0.01).これらの結果は水酸化カルシウム系根管充填剤の存在と歯髄処置による象牙質のpHおよび構造変化が破歯細胞の核数に影響を与えている可能性を示唆している.The root dentine of a human deciduous tooth is physiologically resorbed by multinucleated odontoclasts. Previously, the authors investigated the distribution of the number of nuclei per human odontoclast and showed that the mean number of nuclei per cell is 5.3 and the median is 4. After endodontic treatments of human deciduous teeth, odontoblasts were removed and root canals were filled with the material, alkaline calcium hydroxide. Therefore, the structure of the root dentine after endodontic treatment is different from before treatment. The present study aims to clarify the number of nuclei per odontoclast in human deciduous teeth after endodontic treatments with Vitapex®, a calcium hydroxide-based root canal filling material, and to compare it with that in human deciduous teeth without endodontic treatments. After extraction of deciduous teeth, they were fixed, decalcificated and embedded in paraffin, and six specimens were selected randomly. The specimens were serially sectioned into 4 μm-thick sections and they were stained with TRAP and methyl green, and sections were observed by light microscopy. TRAP-positive cells forming resorptive lacunae on the dentine were identified as odontoclasts, and 99 odontoclasts in anterior teeth and 101 cells in molar ones were investigated to determine the distribution of nuclei per cell. The mean number of nuclei per cell was 20.8 and the median was 14. In the distribution of the number of nuclei per odontoclast, there were statistically significant differences between teeth with endodontic treatments and those without them. These results suggest that the presence of calcium hydroxidebased root canal filling material and root dentine with a different structure may cause change in the number of nuclei of odontoclasts., 北海道歯学会, Japanese - 子どものこころと身体を見守り支援する大規模データ収集とリスク予測モデル構築の試み
西田佳世, 近藤好夫, 西俣はるか, 今村圭吾, 佐藤恭子, 日高聖, 釜崎陽子, 西口美由季, 星野倫範, 藤原卓, 齋藤幹, 山崎要一, 朝田芳信, 八若保孝, 苅部洋行, 新谷誠康, 早崎治明, 小児歯科学雑誌, 54, 1, 155, 155, 25 Feb. 2016
(公社)日本小児歯科学会, Japanese - 北海道大学における教育学習支援システム(ELMS)の歯科矯正学実習への応用
佐藤 嘉晃, 菅原 由紀, 金 壮律, 八若 保孝, 井上 哲, 飯田 俊二, 飯田 順一郎, 日本歯科医学教育学会総会・学術大会プログラム・抄録集, 34回, 119, 119, Jul. 2015
日本歯科医学教育学会, Japanese - Simple and Rapid Conductive Preparation of Wet Biological Samples for SEM Observation: Use of an Asymmetrical Choline-like Room Temperature Ionic Liquid as a Visualizing Agent
ABE SHIGEAKI, HYONO ATSUSHI, KAWAI KOJI, NAKAMURA KOICHI, YAWAKA YASUTAKA, YOSHIDA YASUHIRO, YONEZAWA TETSU, Nano Biomed, 6, 1, 41, 46, 30 Jun. 2014
English - セラミックナノ粒子の細胞刺激性の検討
阿部 薫明, 岩寺 信喜, 半場 悠介, 山方 秀一, 赤坂 司, 八若 保孝, 飯田 順一郎, 亘理 文夫, 古月 文志, 日本歯科理工学会誌, 33, 2, 162, 162, Mar. 2014
(一社)日本歯科理工学会, Japanese - 骨芽細胞へと曝露したマイクロ/ナノマテリアルの生体刺激性の検討
阿部 薫明, 岩寺 信喜, 半場 悠介, 山方 秀一, 赤坂 司, 八若 保孝, 飯田 順一郎, 亘理 文夫, 日本歯科理工学会誌, 32, 5, 373, 373, Sep. 2013
(一社)日本歯科理工学会, Japanese - Evaluation on inhibitory effects of decalcification in various sealant materials using pH-cycle system
USHIMURA Shuya, NAKAMURA Kouichi, YAWAKA Yasutaka, 小児歯科学雑誌, 51, 2, 203, 203, 25 Apr. 2013
Japanese - Trial introduction of rubric for the basics of dental practice in pediatric dentistry
TAKASAKI Chihiro, CHIDA Natsuko, TANEICHI Risa, NAKAMURA Kouichi, IWADERA Nobuki, ABE Tsugumi, HOSHINO Megumi, USHIMURA Shuya, ENDO Kazuki, OSHIMA Shohei, KIKUIRI Takashi, NOJIMA Yasuko, MINAMIKAWA Hajime, YAMADA Jun-ichi, YAGIHARA Sayaka, YOSHIHARA Toshihiro, YAWAKA Yasutaka, 小児歯科学雑誌, 51, 2, 299, 299, 25 Apr. 2013
Japanese - The effects of forced exercise on fear conditioning and memory
NOJIMA Yasuko, YAWAKA Yasutaka, FUNAHASHI Makoto, 北海道歯学雑誌, 33, 1, 10, 16, 15 Sep. 2012
本研究は,恐怖学習を獲得させたラットを用い,恐怖記憶に対する強制運動の影響を明らかにすることを目的として行った.SD系雄性ラット(生後4週齢)を用い,すべてのラットに23.5時間の飲水制限下にて,以下の実験群に分けて実験を行った.運動群:4週間の強制運動(回転速度12~15 m/分,60分/日,5日/週で回転ケージ内を歩行)させた群,非運動群:運動はさせず回転ケージ内に10分間入れた後飼育ケージに戻した(4週間)群,において運動スケジュール終了後に恐怖条件付けを行った.恐怖条件付けはオペラントケージを用いて条件刺激をブザー音30秒,無条件刺激を足底への電気刺激(2.5 mA,29秒,5回/5分)として行った.その後恐怖条件付け学習の獲得について評価するために,条件刺激(ブザー音)に対するすくみ行動を解析した.また,運動群と非運動群の精神的不安度に差が無いかを調べるために,高架十字迷路試験を用いて評価を行った.すくみ行動の割合では,運動群の2日目(11.7±3.8%,n=5)と3日目(0.3±0.3%,n=5)に対して非運動群では2日目(42.7±5.1%,n=5),3日目(22.7±7.9%,n=5)であり,非運動群と比較して運動群のすくみ行動率の有意な低下が認められた.高架十字迷路試験では,運動群と非運動群の間では,全ての項目において有意差は認められなかった.本研究の結果から,強制運動を負荷したことで恐怖記憶が減弱されたことが示された.また,この時運動群と非運動群において精神的不安度に差が無いことも示唆された.以上により強制運動を負荷することで,精神的不安が増強されない程度の恐怖記憶に対してそれを減弱する効果がある可能性が示された., 北海道歯学会, Japanese - エッチング材の違いによるシーラントのヒトエナメル質への微小引張強さ
王 穎, 角田 晋一, 付 佳楽, 加我 正行, 佐野 英彦, 八若 保孝, 特定非営利活動法人日本歯科保存学会学術大会プログラムおよび講演抄録集, 136回, 252, 252, May 2012
(NPO)日本歯科保存学会, Japanese - フッ化物作用時におけるフッ化物中に溶出するカルシウム量に関する検討
中村 光一, 岩寺 信喜, 豊田 有希, 星野 恵, 八若 保孝, 小児歯科学雑誌, 50, 2, 209, 209, 25 Apr. 2012
Japanese - マイクロ/ナノ粒子曝露下の骨芽細胞様細胞と肝細胞の影響
岩寺 信喜, 阿部 薫明, 石川 紘佑, 赤坂 司, 宇尾 基弘, 八若 保孝, 亘理 文夫, 日本歯科理工学会誌, 31, 2, 97, 97, Mar. 2012
(一社)日本歯科理工学会, Japanese - A four-year survey at the clinic of dentistry for children and disabled persons of a university hospital of patients with systemic deseases
HISADA AKINA, 障害者歯科, 32, 3, 243, 243, 30 Sep. 2011
Japanese - The examination of clinical statistics on dental treatment under general anaesthesia for disabled person of the university hospital about the recently 5-year
NAKAMURA KOICHI, 障害者歯科, 32, 3, 485, 485, 30 Sep. 2011
Japanese - Trial introduction of rubric for the basics of dental practice in orthodontics
SATO Yoshiaki, YAMAGATA Shuichi, IWASAKI Hiroshi, KUSAKABE Toyohisa, SUGAWARA KATO Yuki, KIM Takenori, KAJII Takashi, KANEKO Tomoo, YAMAMOTO Takaaki, YOSHIMURA Manabu, YAWAKA Yasutaka, IIDA Junichiro, 北海道歯学雑誌, 32, 1, 46, 54, 15 Sep. 2011
北海道歯学会, Japanese - Questionnaire survey for using rubric and reflection in the basics of dental practice in orthodontics
SATO Yoshiaki, IWASAKI Hiroshi, YAMAGATA Shuichi, KUSAKABE Toyohisa, SUGAWARA KATO Yuki, KIM Takenori, KAJII Takashi, KANEKO Tomoo, YAMAMOTO Takaaki, YOSHIMURA Manabu, YAWAKA Yasutaka, IIDA Junichiro, 北海道歯学雑誌, 32, 1, 55, 61, 15 Sep. 2011
北海道歯学会, Japanese - マイクロ・ナノ無機粒子の各種細胞への影響
岩寺 信喜, 阿部 薫明, 石川 紘佑, 赤坂 司, 宇尾 基弘, 八若 保孝, 亘理 文夫, 日本歯科理工学会誌, 30, 5, 318, 318, Sep. 2011
(一社)日本歯科理工学会, Japanese - Tannin-fluoride preparation attenuates prostaglandin E-2 production by dental pulp cells
Koichi Nakamura, Yoshiaki Deyama, Yoshitaka Yoshimura, Masanor Hashimoto, Masayuki Kaga, Kuniaki Suzuki, Yasutaka Yawaka, MOLECULAR MEDICINE REPORTS, 4, 4, 641, 644, Jul. 2011
English - Effect of N-acetylcysteine on Rat Dental Pulp Cells Cultured on Mineral Trioxide Aggregate
Hajime Minamikawa, Masahiro Yamada, Yoshiaki Deyama, Kuniaki Suzuki, Masayuki Kaga, Yasutaka Yawaka, Takahiro Ogawa, JOURNAL OF ENDODONTICS, 37, 5, 637, 641, May 2011
English - Bioreaction Based on Material Nanosizing and Its Application
WATARI Fumio, YOKOYAMA Atsuro, TOTSUKA Yasunori, KITAGAWA Yoshimasa, YAWAKA Yasutaka, KAWANAMI Masamitsu, 日本歯科医学会誌 = Journal of the Japanese Association for Dental Science : JJDS, 30, 30, 34, 31 Mar. 2011
Japanese - An Impacted Supernumerary Tooth with Backward Movement along the Palate in Maxilla : A Report of Two Cases
IWADERA Nobuki, TANEICHI Risa, SHINOGUCHI Kyoko, NOJIMA Yasuko, MINAMIKAWA Hajime, YOSHIHARA Toshihiro, YAWAKA Yasutaka, The Japanese Journal of Pediatric Dentistry, 49, 5, 465, 473, 2011
In clinical pediatric dentistry, there are many cases of maxillary impacted supernumerary teeth. We report two rare cases in which an inverted impacted supernumerary tooth moved backward along the palate in the maxilla. Neither inverted impacted supernumerary tooth influenced the dentition or occlusion. CT images showed that each supernumerary tooth had erupted into the nasal mucous membrane. Each supernumerary tooth was surgically extracted. The postoperative course was uneventful,without any symptoms.In conclusion, it is possible to extract an inverted impacted supernumerary tooth without clinical influence by understanding the condition in detail. This case report suggests that CT images are effective for understanding the condition of impacted supernumerary teeth., Japanese Society of Pediatric Dentistry, Japanese - Mechanical Properties and Ions Release of S-PRG Filler-containing Pit and Fissure Sealant
KAGA Masayuki, MASUTA Junko, HOSHINO Megumi, GENCHOU Michi, MINAMIKAWA Hajime, HASHIMOTO Masanori, YAWAKA Yasutaka, Nano Biomed, 3, 1, 191, 199, 2011
The purpose of this study was to clarify the properties of functional filler-containing pit and fissure sealants (FS). Seventy-two specimens were prepared and divided into three groups of three resin sealants ( S-PRG filler-containing FS, DELTON and Teethmate F1-2.0) and one glass-ionomer sealant (Fuji III LC). Each of six discs (6 mm in diameter ×3 mm in thickness) was used for 24-h, 4-week and 12-week experiments. Diametral tensile strength (DTS) and ion release were measured. S-PRG FS and Delton showed high values of DTS (23.2 MPa and 23.5 MPa, respectively) after 24 hours of storage. The DTS values of each sealant remained relatively constant. A large amount of fluoride was initially released from the sealants. However, fluoride release did not influence on DTS. S-PRG filler-containing FS released large amounts of strontium, boron and fluoride ions. Filler-containing sealants release large amounts of ions, contributing to antibacterial effects., Nano Biomedical Society, English - An impacted supernumerary tooth with backward movement along the palate in maxilla : a report of two cases.
IWADERA Nobuki, TANEICHI Risa, SHINOGUCHI Kyoko, NOJIMA Yasuko, MINAMIKAWA Hajime, YOSHIHARA Toshihiro, YAWAKA Yasutaka, The Japanese Journal of Pediatric Dentistry, 49, 5, 465, 473, 2011
In clinical pediatric dentistry, there are many cases of maxillary impacted supernumerary teeth. We report two rare cases in which an inverted impacted supernumerary tooth moved backward along the palate in the maxilla. Neither inverted impacted supernumerary tooth influenced the dentition or occlusion. CT images showed that each supernumerary tooth had erupted into the nasal mucous membrane. Each supernumerary tooth was surgically extracted. The postoperative course was uneventful,without any symptoms.In conclusion, it is possible to extract an inverted impacted supernumerary tooth without clinical influence by understanding the condition in detail. This case report suggests that CT images are effective for understanding the condition of impacted supernumerary teeth., Japanese Society of Pediatric Dentistry, Japanese - 水酸化カルシウム製剤による歯根吸収抑制に関する研究 : 根管内清掃とアルカリ性の拡散
豊田 有希, 阿部 亜美, 星野 恵, 吉原 俊博, 加我 正行, 八若 保孝, 小児歯科学雑誌, 48, 5, 601, 601, 10 Nov. 2010
Japanese - マイクロ・ナノ粒子の体内循環挙動の追跡と生体への影響
岩寺 信喜, 石川 紘佑, 伊藤 佐智子, 阿部 薫明, 赤坂 司, 宇尾 基弘, 八若 保孝, 亘理 文夫, 高田 知哉, 米澤 徹, 日本バイオマテリアル学会大会予稿集, 32回, 323, 323, Nov. 2010
日本バイオマテリアル学会, Japanese - Properties of micro-filler content sealants
KAGA M, HASHIMOTO M, ISHIKAWA K, YAWAKA Y, The journal of the Japanese Society for Dental Materials and Devices, 29, 5, 436, 436, 20 Sep. 2010
Compressive strength and fluoride release of fissure sealants were determined. Specimens of 6mm dia. x 3mm thick disk were light illuminated and immersed in 3ml distilled water. The solution was weekly changed. Fluoride released was measured until 90 days. The disk specimens were (n=6) loaded in compression until failure at 24h, 30th day and 90th day. High amount of fluoride was released from Fuji IIILC. The micro-filler filler content resinous fissure sealants (S-PRG containing sealant and DELTON FS+) released moderate fluoride. Compressive strengths of the fissure sealants demonstrated higher strength than FujiIII LC and Teethmate F-1 2.0., The Japanese Society for Dental Materials and Devices (JSDMD), Japanese - マウスに投与したマイクロ・ナノ無機粒子の生体内分布の追跡と細胞への影響
岩寺 信喜, 阿部 薫明, 石川 紘佑, 赤坂 司, 宇尾 基弘, 大口 郁子, 八若 保孝, 亘理 文夫, 米澤 徹, 北海道外科雑誌, 55, 1, 84, 85, Jun. 2010
北海道外科学会, Japanese - 歯科センターおよび病院歯科における障害児(者)歯科診療に関する実態調査
八若 保孝, 増田 純子, 山田 淳一, 源長 美知, 弘中 祥司, 佐々木 仁弘, 原 昌伸, 梶本 祐一郎, 橋本 敏昭, 朝田 芳信, 小児歯科学雑誌, 48, 2, 293, 293, 25 Apr. 2010
Japanese - PAX9遺伝子変異によって姉弟および母に現れた部分性無歯症の例
菊入 崇, 関 みゆき, 谷口 由実, 伊藤 佐智子, 福井 亜実, 八若 保孝, 小児歯科学雑誌, 48, 2, 254, 254, 25 Apr. 2010
Japanese - S-PRGフィラー含有新規シーラント材の歯質脱灰抑制効果
源長 美知, 加我 正行, 増田 純子, 八若 保孝, 小児歯科学雑誌, 48, 2, 221, 221, 25 Apr. 2010
Japanese - ラット歯髄由来細胞におけるグラスアイオノマーセメント浸出液によるPGE_2産生ならびにHY材の作用
中村 光一, 吉村 善隆, 橋本 正則, 加我 正行, 八若 保孝, 小児歯科学雑誌, 48, 2, 280, 280, 25 Apr. 2010
Japanese - マウス大脳皮質体性感覚野におけるニューロン周囲オリゴデンドロサイトの化学的特性の検討
高崎 千尋, 大島 昇平, 岡田 理恵子, 八若 保孝, 小児歯科学雑誌, 48, 2, 25 Apr. 2010
Japanese - Idiopathic osteosclerosis in the mandible associated with abnormal tooth root formation
Shohei Oshima, Junichi Suzuki, Yasutaka Yawaka, pediatric dental journal, 20, 1, 91, 94, 2010
English - A Survey on the Dental Treatment for the Disable and Medically Compromised Children in Pediatric Dentists in Private Practice : 2. Cooperation and Future Problem
YAWAKA Yasutaka, TANEICHI Risa, YOSHIHARA Toshihiro, SUZUKI Hiroyuki, KAJIMOTO Yuichiro, HASHIMOTO Toshiaki, SUZUKI Yasuo, IGARASHI Seiji, FUKUTA Osamu, TUCHIYA Tomoyuki, TSUCHIYA Tomoyuki, The Japanese Journal of Pediatric Dentistry, 48, 1, 64, 72, 2010
In order to investigate the actual status of the dental treatment for the disabled patients in private practice, we conducted questionnaire surveys and got answers from 450 specialists out of 1404 specialists in private practice that provided pediatric dentistry (a response rate of 32.1%).As the results, on the dental treatments of disabled children, 90% of the specialists of pediatric dentistry in private practice had the second or the third grade dental institution as an introduced dental hospital. Most of the introduced dental institutions were the university dental hospital. However, the specialists with the cooperation with the educational institutes for disabled children was slight 19.1%. Similarly, the specialists with the cooperation with the administration was 24.4%. Therefore, it was shown that the cooperation between the specialists in private practice and the educational institutes for the disabled children or the administration was insufficient. And it seemed that many problems of time, cost, physical strength and facility such as insurance systems which is not suitable for present state, limit in the practitioner and regional differences existed in the dental treatments of the disabled children by the special practitioners., Japanese Society of Pediatric Dentistry, Japanese - A Survey on the Dental Treatment for the Disable and Medically Compromised Children in Pediatric Dentists in Private Practice : 1. Actual Status
TANEICHI Risa, YOSHIHARA Toshihiro, SUZUKI Hiroyuki, KAJIMOTO Yuichiro, HASHIMOTO Toshiaki, SUZUKI Yasuo, IGARASHI Seiji, FUKUTA Osamu, TUCHIYA Tomoyuki, YAWAKA Yasutaka, YAWAKA Yasutaka, The Japanese Journal of Pediatric Dentistry, 48, 1, 56, 63, 2010
In order to investigate the actual status of the dental treatment for disabled patients in private practice, we conducted questionnaire surveys and got answers from 450 specialists out of 1404 specialists in private practice that provided pediatric dentistry (a response rate of 32.1%).About half of the respondents (48.7%) had 26−30 years of clinical experience. A ratio of the number of disabled children to all patients in most private practices was 1−5%. A small number of respondents (13.3%) separated the time for the treatment between normal and disabled children. And most of the reasons for visiting the private practice were consisted of the patients or their parents own motive. These results indicated that expert specialists in each area had been performing comprehensive and high-quality treatment for disabled children as well as the normal patients, regardless of the patients age. And it seemed that the specialists in private practice played a role as primary care dentists for the patients. On the other hand, there was great variability related to the age of the respondents in these questionnaire surveys. Therefore, it seemed to be necessary for specialists over generations to share the information for technology and knowledge associated with the dental treatment for disabled children., Japanese Society of Pediatric Dentistry, Japanese - Shear Bond Strength and Fluoride Release and Recharge Performance of Fluoride Releasing Orthodontic Adhesive
NAKAMURA Koichi, NOMURA Naoko, TOYOTA Yuki, MINAMIKAWA Hajime, KAGA Masayuki, YAWAKA Yasutaka, The Japanese Journal of Pediatric Dentistry, 48, 1, 73, 80, 2010
The purpose of this study was to evaluate the shear bond strengths of fluoride releasing orthodontic adhesive to human enamel. Also, we examined the release of the fluorine of each adhesion materials and recharge performance. As a result, Superbond orthomite is the strongest (16.7 MPa) which deteriorated in order of Fuji ortho LC (14.2 MPa), Krasper F (12.9 MPa), Beauty ortho bond (10.1 MPa),Beauty ortho bond salivatect (7.4 MPa). As for Beauty ortho bond, the enamel surface was smooth as a result of SEM observation after the shear bond strength test. However, the enamel prism structure was exposed in Superbond orthomite and Krasper F which showed strong adhesive strength, and injury to enamel surface. By the measurement of the amount of release of the fluorine and recharge performance, most fluorine released it after one day of the measurement. On the second day, the amount of fluoride release decreased with the third day and became the equilibrium from day 4 to day 7. The most fluoride ions were released from Fuji ortho LC as resin modified glass ionomer cement. Beauty ortho bond which contained S-PRG filler followed it. It had the same tendency after fluoride recharge. Fluoride releasing orthodontic adhesive has moderate adhesive strength with little effect on enamel surface. These had the ability for the release of larger amounts of fluorine and recharge performance, and it was shown that it was effective materials for dental caries during orthodontic treatment., Japanese Society of Pediatric Dentistry, Japanese - Comparison of Enamel Demineralization between Deciduous and Permanent Teeth Using the Automatic pH-cycling System
SUGAI Makoto, MATSUDA Yasuhiro, NAGAYAMA Masato, KAGA Masayuki, YAWAKA Yasutaka, The Japanese Journal of Pediatric Dentistry, 48, 1, 48, 55, 2010
A forecast of demineralization and remineralization on teeth in the oral cavity is important to prevent and treatment of the occurrence and progression of caries. The automatic pH-cycling system developed by Mastuda et al. can simulate daily changes in pH that occur in the oral cavity. In the previous study, permanent teeth were used to evaluate the caries progression and inhibition. However,there was no study that used deciduous teeth. Therefore, the aim of this study was to compare and evaluate the demineralization on deciduous and permanent tooth enamel using the automatic pHcycling system.A 150-μm thick single-section specimen was prepared from a human extracted deciduous molar and permanent third molar and polished surface was coated with Sticky Wax. The experimented condition was 9 pH cycles/day for four weeks, and a demineralizing solution (lactic acid solution, pH 4.5) and remineralizing solution (HEPES solution, pH 7.0) were used to reproduce the same pH changes that typically occur in the oral cavity. During the interval, the specimen was left in the remineralization solution. The Transverse Microradiography(TMR) images of each specimen were examined to evaluate the progression of artificial caries with respect to integrated mineral loss(IML) and lesion depth(Ld) at week 1, week 2, week 3 and week 4.Integrated mineral loss of the deciduous teeth was significantly higher than that of the permanent teeth at all weeks. Lesion depth of the deciduous teeth was significantly higher than that of the permanent teeth at all weeks. Especially, integrated mineral loss and lesion depth of the deciduous tooth at week 4 was higher than that at other weeks.The results suggested that the occurrence and progression of demineralization of the deciduous tooth is higher than the permanent tooth, and we concluded that the automatic pH-cycling system was qualified as a system that evaluated demineralization of the deciduous tooth and the permanent tooth. It could be beneficially employed to clarify the difference of the deciduous tooth and the permanent toothinoralcavity., Japanese Society of Pediatric Dentistry, Japanese - 日本人小児の永久歯先天性欠如に関する疫学的調査
山崎 要一, 岩崎 智憲, 早崎 治明, 齋藤 一誠, 徳冨 順子, 八若 保孝, 井上 美津子, 朝田 芳信, 田村 康夫, 嘉ノ海 龍三, 牧 憲司, 吉原 俊博, 船津 敬弘, 手島 陽子, 上里 千夏, 山下 一恵, 井出 正道, 栗山 千裕, 近藤 亜子, 嘉藤 幹夫, 渡邉 京子, 藤田 優子, 長谷川 大子, 稲田 絵美, 日本小児歯科学会学術委員会, 小児歯科学雑誌, 48, 1, 29, 39, 2010
(公社)日本小児歯科学会, Japanese - 障がい者歯科医療体制整備事業「北海道障害者歯科医療協力医制度」実地研修『講義』テキスト
北海道・北海道歯科医師会, 2010 - A survey on the dental treatment for the disable and medically compromised children in pediatric dentists in private practice.
YAWAKA Yasutaka, TANEICHI Risa, YOSHIHARA Toshihiro, SUZUKI Hiroyuki, KAJIMOTO Yuichiro, HASHIMOTO Toshiaki, SUZUKI Yasuo, IGARASHI Seiji, FUKUTA Osamu, TUCHIYA Tomoyuki, TSUCHIYA Tomoyuki, The Japanese Journal of Pediatric Dentistry, 48, 1, 64, 72, 2010
In order to investigate the actual status of the dental treatment for the disabled patients in private practice, we conducted questionnaire surveys and got answers from 450 specialists out of 1404 specialists in private practice that provided pediatric dentistry (a response rate of 32.1%).As the results, on the dental treatments of disabled children, 90% of the specialists of pediatric dentistry in private practice had the second or the third grade dental institution as an introduced dental hospital. Most of the introduced dental institutions were the university dental hospital. However, the specialists with the cooperation with the educational institutes for disabled children was slight 19.1%. Similarly, the specialists with the cooperation with the administration was 24.4%. Therefore, it was shown that the cooperation between the specialists in private practice and the educational institutes for the disabled children or the administration was insufficient. And it seemed that many problems of time, cost, physical strength and facility such as insurance systems which is not suitable for present state, limit in the practitioner and regional differences existed in the dental treatments of the disabled children by the special practitioners., Japanese Society of Pediatric Dentistry, Japanese - A survey on the dental treatment for the disable and medically compromised children in pediatric dentists in private practice.
TANEICHI Risa, YOSHIHARA Toshihiro, SUZUKI Hiroyuki, KAJIMOTO Yuichiro, HASHIMOTO Toshiaki, SUZUKI Yasuo, IGARASHI Seiji, FUKUTA Osamu, TUCHIYA Tomoyuki, YAWAKA Yasutaka, YAWAKA Yasutaka, The Japanese Journal of Pediatric Dentistry, 48, 1, 56, 63, 2010
In order to investigate the actual status of the dental treatment for disabled patients in private practice, we conducted questionnaire surveys and got answers from 450 specialists out of 1404 specialists in private practice that provided pediatric dentistry (a response rate of 32.1%).About half of the respondents (48.7%) had 26−30 years of clinical experience. A ratio of the number of disabled children to all patients in most private practices was 1−5%. A small number of respondents (13.3%) separated the time for the treatment between normal and disabled children. And most of the reasons for visiting the private practice were consisted of the patients or their parents own motive. These results indicated that expert specialists in each area had been performing comprehensive and high-quality treatment for disabled children as well as the normal patients, regardless of the patients age. And it seemed that the specialists in private practice played a role as primary care dentists for the patients. On the other hand, there was great variability related to the age of the respondents in these questionnaire surveys. Therefore, it seemed to be necessary for specialists over generations to share the information for technology and knowledge associated with the dental treatment for disabled children., Japanese Society of Pediatric Dentistry, Japanese - Comparison of enamel demineralization between deciduous and permanent teeth using the automatic pH-cycling system.
SUGAI Makoto, MATSUDA Yasuhiro, NAGAYAMA Masato, KAGA Masayuki, YAWAKA Yasutaka, The Japanese Journal of Pediatric Dentistry, 48, 1, 48, 55, 2010
A forecast of demineralization and remineralization on teeth in the oral cavity is important to prevent and treatment of the occurrence and progression of caries. The automatic pH-cycling system developed by Mastuda et al. can simulate daily changes in pH that occur in the oral cavity. In the previous study, permanent teeth were used to evaluate the caries progression and inhibition. However,there was no study that used deciduous teeth. Therefore, the aim of this study was to compare and evaluate the demineralization on deciduous and permanent tooth enamel using the automatic pHcycling system.A 150-μm thick single-section specimen was prepared from a human extracted deciduous molar and permanent third molar and polished surface was coated with Sticky Wax. The experimented condition was 9 pH cycles/day for four weeks, and a demineralizing solution (lactic acid solution, pH 4.5) and remineralizing solution (HEPES solution, pH 7.0) were used to reproduce the same pH changes that typically occur in the oral cavity. During the interval, the specimen was left in the remineralization solution. The Transverse Microradiography(TMR) images of each specimen were examined to evaluate the progression of artificial caries with respect to integrated mineral loss(IML) and lesion depth(Ld) at week 1, week 2, week 3 and week 4.Integrated mineral loss of the deciduous teeth was significantly higher than that of the permanent teeth at all weeks. Lesion depth of the deciduous teeth was significantly higher than that of the permanent teeth at all weeks. Especially, integrated mineral loss and lesion depth of the deciduous tooth at week 4 was higher than that at other weeks.The results suggested that the occurrence and progression of demineralization of the deciduous tooth is higher than the permanent tooth, and we concluded that the automatic pH-cycling system was qualified as a system that evaluated demineralization of the deciduous tooth and the permanent tooth. It could be beneficially employed to clarify the difference of the deciduous tooth and the permanent toothinoralcavity., Japanese Society of Pediatric Dentistry, Japanese - Frequency of congenitally missing permanent teeth in Japanese children.
The Japanese Journal of Pediatric Dentistry, 48, 1, 29, 39, 2010 - ナノ粒子の生体反応誘発性 Biointeractive、Bioreactive特性について
亘理 文夫, 横山 敦郎, 赤坂 司, 宇尾 基弘, 阿部 薫明, 伊藤 佐智子, 大口 郁子, 八若 保孝, 日本バイオマテリアル学会大会予稿集, 31回, 195, 195, Nov. 2009
日本バイオマテリアル学会, Japanese - 無機ケイ酸塩ナノチューブ(イモゴライト)を用いた細胞培養担体の開発
石川 紘佑, 赤坂 司, 阿部 薫明, 宇尾 基弘, 八若 保孝, 亘理 文夫, 歯科材料・器械, 28, 5, 352, 352, Sep. 2009
(一社)日本歯科理工学会, Japanese - カーボンナノチューブ(CNT)に対する肝細胞の挙動
伊藤 佐智子, 赤坂 司, 八若 保孝, 亘理 文夫, 歯科材料・器械, 28, 5, 355, 355, Sep. 2009
(一社)日本歯科理工学会, Japanese - 肝臓細胞の増殖におよぼすカーボンナノチューブの影響について
伊藤 佐智子, 赤坂 司, 八若 保孝, 亘理 文夫, 北海道外科雑誌, 54, 1, 76, 76, Jun. 2009
北海道外科学会, Japanese - Effect of Mineral Trioxide Aggregate on Rat Clonal Dental Pulp Cells: Expression of Cyclooxygenase-2 mRNA and Inflammation-related Protein via Nuclear Factor Kappa B Signaling System
Hajime Minamikawa, Yoshiaki Deyama, Kouichi Nakamura, Yoshitaka Yoshimura, Masayuki Kaga, Kuniaki Suzuki, Yasutaka Yawaka, JOURNAL OF ENDODONTICS, 35, 6, 843, 846, Jun. 2009
English - Bone morphogenetic protein-2 down-regulates miR-206 expression by blocking its maturation process
Mari M. Sato, Masayuki Nashimoto, Takenobu Katagiri, Yasutaka Yawaka, Masato Tamura, BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 383, 1, 125, 129, May 2009
English - 自動pHサイクル装置を用いた乳歯および永久歯エナメル質脱灰の比較
須貝 誠, 松田 康裕, 永山 正人, 加我 正行, 八若 保孝, 小児歯科学雑誌, 47, 2, 373, 373, 25 Apr. 2009
Japanese - フッ素徐放性矯正ブラケット接着材のヒトエナメル質接着効果
中村 光一, 豊田 有希, 南川 元, 橋本 正則, 加我 正行, 八若 保孝, 小児歯科学雑誌, 47, 2, 226, 226, 25 Apr. 2009
Japanese - 骨芽細胞様細胞の成長に及ぼすImogoliteおよびCNTsスキャホールドの影響
石川 紘佑, 赤坂 司, 鈴木 正哉, 亘理 文夫, 八若 保孝, 小児歯科学雑誌, 47, 2, 347, 347, Apr. 2009
(公社)日本小児歯科学会, Japanese - 正常肝細胞と癌肝細胞に対するカーボンナノチューブ(CNT)の影響について
伊藤 佐智子, 赤坂 司, 亘理 文夫, 八若 保孝, 小児歯科学雑誌, 47, 2, 353, 353, Apr. 2009
(公社)日本小児歯科学会, Japanese - 肝臓細胞の増殖に及ぼすCNTの影響
伊藤 佐智子, 赤坂 司, 八若 保孝, 亘理 文夫, 歯科材料・器械, 28, 2, 46, 46, Mar. 2009
(一社)日本歯科理工学会, Japanese - Possible application of flow cytometry for evaluation of the structure and functional status of WASP in peripheral blood mononuclear cells
Masaru Nakajima, Masafumi Yamada, Koji Yamaguchi, Yukio Sakiyama, Atsushi Oda, David L. Nelson, Yasutaka Yawaka, Tadashi Ariga, EUROPEAN JOURNAL OF HAEMATOLOGY, 82, 3, 223, 230, Mar. 2009
English - Bone morphogenetic protein-2 enhances Wnt/beta-catenin signaling-induced osteoprotegerin expression
Mari M. Sato, Aiko Nakashima, Masayuki Nashimoto, Yasutaka Yawaka, Masato Tamura, GENES TO CELLS, 14, 2, 141, 153, Feb. 2009
English - 障がい者歯科医療体制整備事業「北海道障害者歯科医療協力医制度」実地研修『講義』テキスト
北海道・北海道歯科医師会, 2009 - Faculty development in Graduate School of Dental Medicine and School of Dental Medicine, Hokkaido University
八若 保孝, 加我 正行, 飯塚 正, 山本 恒之, 佐藤 嘉晃, 根岸 淳, 北川 善政, 鈴木 邦明, 森田 学, 吉田 重光, Journal of higher education and lifelong learning, 16, 153, 159, Dec. 2008
Activities of Faculty Development (FD) in the Graduate School of Dental Medicine and School of Dental Medicine of Hokkaido University consist of lectures on FD, workshops on FD and student evaluation of undergraduate lectures. Basically, the lectures on FD are held 4 times every year. The speakers are selected not only from the faculty of Hokkaido University but also from outside the university. A workshop on FD is held once every year. Usually about 30 faculty members of the Graduate School of Dental Medicine participate in the workshop that takes place for two days in a hotel out of campus. The student evaluation of undergraduate lectures is conducted twice every year; i.e., for the lectures in the first semester and the second semester. The lectures and workshop on FD began in 2000, and the student evaluation of undergraduate lectures began in 1997. Many faculty members have participated in the lectures and workshops on FD and made efforts to develop their competence. The student evaluation of undergraduate lectures showed a gain in the score. However, there are a few faculty members who have a negative view of FD in practice., 北海道大学高等教育機能開発総合センター, Japanese - 本大学病院小児歯科における最近5年間の障害を有する初診患者の実態調査
野島 靖子, 岩寺 信喜, 種市 梨紗, 中村 光一, 寺林 えり, 吉原 俊博, 加我 正行, 八若 保孝, 障害者歯科, 29, 3, 464, 464, 30 Sep. 2008
Japanese - The difference of the effect of multi-walled carbon nanotubes on human hepatic normal and cancer cells
ITOH S., AKASAKA T., YAWAKA Y., WATARI F., Journal of the Japanese Society for Dental Materials and Devices, 27, 5, 388, 388, 25 Sep. 2008
The Japanese Society for Dental Materials and Devices (JSDMD), Japanese - ケイ酸塩ナノチューブ(イモゴライト)上での骨芽細胞培養
石川 紘佑, 赤坂 司, 八若 保孝, 亘理 文夫, 歯科材料・器械, 27, 5, 433, 433, Sep. 2008
(一社)日本歯科理工学会, Japanese - 小児歯科開業医における障害児歯科診療に関する実態調査 : 2. 連携について 3. 今後の課題について
八若 保孝, 福田 理, 鈴木 康生, 五十嵐 清治, 梶本 祐一郎, 鈴木 広幸, 橋本 敏昭, 種市 梨紗, 吉原 俊博, 土屋 友幸, 小児歯科学雑誌, 46, 2, 241, 241, 25 Apr. 2008
Japanese - 小児歯科開業医における障害児歯科診療に関する実態調査 : 1. 現状について
吉原 俊博, 種市 梨紗, 鈴木 広幸, 梶本 祐一郎, 橋本 敏昭, 鈴木 康生, 五十嵐 清治, 福田 理, 土屋 友幸, 八若 保孝, 小児歯科学雑誌, 46, 2, 242, 242, 25 Apr. 2008
Japanese - 鼻腔に近接した上顎正中埋伏過剰歯の状態と対応
岩寺 信喜, 野島 靖子, 南川 元, 種市 梨紗, 吉原 俊博, 八若 保孝, 小児歯科学雑誌, 46, 2, 273, 273, 25 Apr. 2008
Japanese - グラスアイオノマーセメントのフッ素徐放と機械的強度変化
南川 元, 塩沢 真帆, 中村 光一, 石川 絋佑, 橋本 正則, 加我 正行, 八若 保孝, 小児歯科学雑誌, 46, 2, 229, 229, 25 Apr. 2008
Japanese - 材料のナノサイジングに基づく生体反応とその応用
亘理文夫, 横山敦郎, 戸塚靖則, 北川善政, 森田学, 八若保孝, 川浪雅光, 日本歯科医学会誌, 27, 90, 90, Mar. 2008
日本歯科医学会, Japanese - Effect of water on bonding of one-bottle self-etching adhesives
Masanori Hashimoto, Shinichi Fujita, Masayuki Kaga, Yasutaka Yawaka, DENTAL MATERIALS JOURNAL, 27, 2, 172, 178, Mar. 2008
English - Wnt/β-cateninとBMP-2シグナルによるOPG遺伝子の発現調節機構の解析
佐藤 真理, 田村 正人, 八若 保孝, 小児歯科学雑誌, 46, 2, 317, 317, 2008
一般社団法人 日本小児歯科学会, Japanese - Orthodontic and restorative treatments of an impacted canine in a child with Down syndrome: A case report
Taneichi Risa, Yoshihara Toshihiro, Oshima Syohei, Yawaka Yasutaka, Ped Dent J, 18, 2, 210, 213, 2008
A 10 year-3 month-old boy with root resorption of the right central incisor associated with impaction of the right canine in the maxilla was referred to our dental clinic by a private general dental practitioner. He had Down syndrome with slight intellectual impairment and no congenital heart disease. Since the results of the mental development age test indicated that his development age was probably more than 4 years and 8 months, we decided that we could treat the patient by using behavior management techniques. We explained the procedures for comprehensive dental treatment in a simplified manner to the patient by using behavior management techniques. The use of enhanced behavior management techniques enabled him to accept comprehensive dental treatment that included extraction of the central incisor and orthodontic and restorative treatments of the impacted canine. We were able to complete the treatments and obtain a good outcome., The Japanese Society of Pediatric Dentistry, English - 外傷歯への処置に関する新しい知見
北海道歯学雑誌, 29, 1, 108, 111, 2008 - ラットにおける亜鉛過剰摂取による銅吸収阻害機構
北海道歯学雑誌, 29, 1, 89, 98, 2008 - Repeated immobilization stress in the early postnatal period increases stress response in adult rats
Toshihiro Yoshihara, Yasutaka Yawaka, PHYSIOLOGY & BEHAVIOR, 93, 1-2, 322, 326, Jan. 2008
English - 障がい者歯科医療体制整備事業「北海道障害者歯科医療協力医制度」実地研修『講義』テキスト
北海道・北海道歯科医師会, 2008 - 上顎中切歯の根吸収を伴う上顎埋伏犬歯の萌出誘導 : Down 症候群児に対する一例
種市 梨紗, 吉原 俊博, 大島 昇平, 八若 保孝, 障害者歯科 = JOURNAL OF THE JAPANESE SOIETY FOR DISABILITY AND ORAL HEALTH, 28, 3, 20 Sep. 2007
Japanese - B28 Cell Culture on a Imogolite Scaffold
Ishikawa Kosuke, Akasaka Tsukasa, Yawaka Yasutaka, Suzuki Masaya, Watari Fumio, 粘土科学討論会講演要旨集, 51, 144, 145, 12 Sep. 2007
The Clay Science Society of Japan, Japanese - In vitro durability of one-bottle resin adhesives bonded to dentin
Masanori Hashimoto, Shinichi Fujita, Masayuki Kaga, Yasutaka Yawaka, DENTAL MATERIALS JOURNAL, 26, 5, 677, 686, Sep. 2007
English - Flow cytometry を用いたヒト末梢血単核球内WASP分子の構造的, 機能的解析に関する研究
中島 督, 加我 正行, 八若 保孝, 小児歯科学雑誌, 45, 2, 365, 365, 25 May 2007
Japanese - ヒト乳歯の生理的歯根吸収下における破歯細胞のアポトーシスの免疫組織化学的研究
谷口 由実, 福井 亜実, 八若 保孝, 小児歯科学雑誌, 45, 2, 315, 315, 25 May 2007
Japanese - グラスアイオノマーセメントのフッ素リチャージ時におけるフッ素浸透深度について
中村 光一, 加我 正行, 橋本 正則, 八若 保孝, 小児歯科学雑誌, 45, 2, 285, 285, 25 May 2007
Japanese - Dentin Bonding and Bond Durability of One-bottle Adhesive Resins
FUJITA S., HASHIMOTO M., KAGA M., YAWAKA Y., Journal of the Japanese Society for Dental Materials and Devices, 26, 2, 93, 93, 25 Apr. 2007
The Japanese Society for Dental Materials and Devices (JSDMD), Japanese - A Seven-year Survey at the Pediatric Dentistry Clinic of a University Hospital of Patients with Systemic Diseases
YAWAKA Yasutaka, IWABUCHI Hideaki, ITO Sachiko, KAGA Masayuki, 小児歯科学雑誌, 45, 5, 623, 631, 2007
Japanese - ペースト・ペーストタイプの新グラスアイオノマーセメントの歯質接着性とフッ素徐放について.
加我正行, 岩渕英明, 中村光一, 橋本正則, 八若保孝, 小児歯科学雑誌, 45, 1, 81, 87, 2007 - Flow cytometryを用いたヒト末梢血単核球内WASP分子の構造的・機能的解析に関する研究
中島 督, 山田 雅文, 山口 晃司, 崎山 幸雄, 八若 保孝, 有賀 正, 北海道歯学雑誌, 27, 2, 190, 200, Dec. 2006
北海道歯学会, Japanese - Wiskott-Aldrich 症候群にみられた歯の形成障害
三浦 真理, 小島 寛, 及川 透, 八若 保孝, 障害者歯科 = JOURNAL OF THE JAPANESE SOIETY FOR DISABILITY AND ORAL HEALTH, 27, 3, 487, 487, 20 Sep. 2006
Japanese - One-bottle 接着性レジンシステムの吸水性とナノリーケージ
藤田 慎一, 橋本 正則, 中村 光一, 加我 正行, 八若 保孝, 小児歯科学雑誌, 44, 2, 276, 276, 25 Apr. 2006
Japanese - グラスアイオノマー系充填材料のフッ素リチャージ量とリチャージ時間との相関について
石川 紘佑, 佐藤 真理, 中村 光一, 橋本 正則, 加我 正行, 八若 保孝, 小児歯科学雑誌, 44, 2, 280, 280, 25 Apr. 2006
Japanese - ヒト乳歯の生理的歯根吸収下における破歯細胞のアポトーシスに関する免疫組織学的研究
北海道歯学雑誌, 27, 2, 149, 158, 2006 - Dentin Bonding of One-bottle Adhesive Resins
FUJITA Shinichi, HASHIMOTO Masanori, KAGA Masayuki, YAWAKA Yasutaka, 小児歯科学雑誌, 44, 4, 556, 566, 2006
Japanese - 研磨面性状がオールインワン・アドヒーシブの接着強さに及ぼす影響
吉田 英史, 宇野 滋, 野田坂 佳伸, 加我 正行, 八若 保孝, 平野 進, 歯科材料・器械, 25, 1, 47, 53, 2006
(一社)日本歯科理工学会, Japanese - 障がい者歯科医療体制整備事業「北海道障害者歯科医療協力医制度」実地研修『講義』テキスト
北海道・北海道歯科医師会, 2006 - 外傷により下顎頭骨折を生じた小児の咬合変化
八若 保孝, 岩渕 英明, 黒嶋 玲奈, 谷口 由実, 加我 正行, 小児歯科学雑誌, 43, 2, 343, 343, 25 Apr. 2005
Japanese - 歯科的協力度の向上を通して上顎中切歯の萌出誘導を行った障害児の一例
障害者歯科, 26, 76, 82, 2005 - 障害者歯科医療体制整備事業「北海道障害者歯科医療協力医制度」実地研修『講義』テキスト2
北海道・北海道歯科医師会, 2005 - ペースト/ペーストタイプ修復用光硬化型グラスアイオノマーセメントの歯質接着とフッ素徐放について
加我 正行, 八若 保孝, 岩渕 英明, 障害者歯科 = JOURNAL OF THE JAPANESE SOIETY FOR DISABILITY AND ORAL HEALTH, 25, 3, 290, 290, 30 Sep. 2004
Japanese - 乳歯セメント質の組織学的研究 : 吸収と添加について
八若 保孝, 福井 亜実, 谷口 由実, 加我 正行, 小口 春久, 小児歯科学雑誌, 42, 2, 251, 251, 25 Apr. 2004
Japanese - Root resorption of human deciduous teeth with apical periodontitis by cultured osteoclasts
Yasutaka Yawaka, Masakazu Osanai, Youichi Shirai, Tomokazu Hasegawa, Masayuki Kaga, Haruhisa Oguchi, Pediatric Dental Journal, 14, 1, 121, 126, 2004
English - Changes in occlusal contact area and average bite pressure during treatment of anterior crossbite in primary dentition
Yasutaka Yawaka, Syouji Hironaka, Akemi Akiyama, Ikuko Matzuduka, Chihiro Takasaki, Haruhisa Oguchi, Journal of Clinical Pediatric Dentistry, 28, 1, 75, 79, Sep. 2003
English - Histological study of deposited cementum in human deciduous teeth with pathological root resorption
Y Yawaka, M Osanai, A Akiyama, R Ninomiya, H Oguchi, ANNALS OF ANATOMY-ANATOMISCHER ANZEIGER, 185, 4, 335, 341, Jul. 2003
English - A Five-year Survey of Patients Visiting the Pediatric Dentistry Clinic of a University Dental Hospital for the First Time I. Characteristics of Patients Visiting the Clinic for the First Time
KIKUCHI Tomoe, YAWAKA Yasutaka, NAKAO Kayoko, HIRONAKA Shouji, KAGA Masayuki, OGUCHI Haruhisa, 『小児歯科学雑誌』, 41, 1, 271, 277, 2003
Japanese - A Five-year Survey of Patients Visiting the Pediatric Dentistry Clinic of a University Dental Hospital for the First Time II. Characteristics of Patients Making Regular Visits to Our Clinic
NAKAO Kayoko, YAWAKA Yasutaka, KIKUCHI Tomoe, HIRONAKA Shouji, KAGA Masayuki, OGUCHI Haruhisa, 『小児歯科学雑誌』, 41, 1, 278, 284, 2003
Japanese - 溺水後低酸素脳症により大脳に高度の萎縮を認めた症例の嚥下障害の経年変化
木下 憲治, 阿部 倫子, 八若 保孝, 小口 春久, 障害者歯科, 23, 3, 425, 425, 20 Sep. 2002
Japanese - Delayed eruption of premolars with periodontitis of primary predecessors and a cystic lesion: A case report
Y. Yawaka, M. Kaga, M. Osanai, A. Fukui, H. Oguchi, International Journal of Paediatric Dentistry, 12, 1, 53, 60, Jan. 2002
English - Cystic lesion によって左側下顎第二乳臼歯が偏位した一症例
加我 正行, 八若 保孝, 小口 春久, 小児歯科学雑誌, 39, 2, 404, 404, 01 Apr. 2001
Japanese - 低カルシウム環境において形成された破骨細胞の形態について
八若 保孝, 竹山 禎章, 福井 亜実, 吉村 善隆, 小口 春久, 小児歯科学雑誌, 39, 2, 358, 358, 01 Apr. 2001
Japanese - デンタルプレスケールを用いた臼歯部交叉咬合の被蓋改善前後の変化
松塚 育子, 八若 保孝, 弘中 祥司, 高崎 千尋, 福井 亜実, 小口 春久, 小児歯科学雑誌, 39, 2, 302, 302, 01 Apr. 2001
Japanese - Low calcium environment effects osteoprotegerin ligand/osteoclast differentiation factor
S Takeyama, Y Yoshimura, Y Shirai, Y Deyama, T Hasegawa, Y Yawaka, T Kikuiri, A Matsumoto, H Fukuda, BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 276, 2, 524, 529, Sep. 2000
English - ヒト乳歯歯根吸収に関する微細形態学的研究 : 歯根吸収面上における破歯細胞の分布
長内 正数, 土門 卓文, 八若 保孝, 小口 春久, 小児歯科学雑誌, 38, 2, 467, 467, 01 Apr. 2000
Japanese - Ultrastructural study of the root dentine surface resuming resorption on human deciduous teeth
T Domon, M Osanai, Y Yawaka, R Suzuki, S Takahashi, T Yamamoto, M Wakita, ANNALS OF ANATOMY-ANATOMISCHER ANZEIGER, 182, 2, 175, 184, Mar. 2000
English - Effect of extracellular calcium concentrations on osteoclast differentiation in vitro
Y Shirai, Y Yoshimura, Y Yawaka, T Hasegawa, T Kikuiri, S Takeyama, A Matsumoto, H Oguchi, BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 265, 2, 484, 488, Nov. 1999
English - ヒト破歯細胞の微細形態学的研究歯髄処置経験による相違について
長内 正数, 土門 卓文, 八若 保孝, 脇田 稔, 小口 春久, 歯科基礎医学会雑誌, 41, 5, 461, 461, 20 Aug. 1999
歯科基礎医学会, Japanese - 低カルシウム環境下における破骨細胞発現の組織学的考察
白井 洋一, 吉村 善隆, 八若 保孝, 長谷川 智一, 竹山 禎章, 松本 章, 小口 春久, 小児歯科学雑誌, 37, 2, 321, 321, 01 Apr. 1999
一般社団法人 日本小児歯科学会, Japanese - 上顎乳前歯唇側傾斜を目的とした矯正力の後継永久歯に及ぼす影響
八若 保孝, 秋山 明美, 長内 正数, 弘中 祥司, 原田 理恵, 小口 春久, 小児歯科学雑誌, 37, 1, 55, 61, Mar. 1999
(公社)日本小児歯科学会, Japanese - 第一第二鰓弓症候群の患者にみられた上顎口蓋部の石灰化物について
原田 理恵, 八若 保孝, 長内 正数, 小口 春久, 小児歯科学雑誌, 36, 2, 269, 269, 01 Apr. 1998
Japanese - 外傷後に歯冠変色をきたした幼若永久前歯の診断法について
菊入 崇, 白川 哲夫, 加我 正行, 八若 保孝, 小口 春久, 小児歯科学雑誌, 36, 2, 367, 367, 01 Apr. 1998
Japanese - ヒト破歯細胞に関する微細形態学的研究 : 歯髄処置経験の有無による相違について
長内 正数, 土門 卓文, 八若 保孝, 秋山 明美, 原田 理恵, 小口 春久, 小児歯科学雑誌, 36, 2, 303, 303, 01 Apr. 1998
Japanese - 上顎乳前歯唇側傾斜を目的とした矯正力の後継永久歯に及ぼす影響
八若 保孝, 秋山 明美, 長内 正数, 弘中 祥司, 原田 理恵, 小口 春久, 小児歯科学雑誌, 36, 2, 277, 277, 01 Apr. 1998
Japanese - 乳前歯反対咬合の被蓋改善前後における咬合接触面積の変化
弘中 祥司, 八若 保孝, 秋山 明美, 長内 正数, 原田 理恵, 小口 春久, 小児歯科学雑誌, 36, 2, 278, 278, 01 Apr. 1998
Japanese - A Case of Congenital Neurofibroma on the Palatal Region of the Maxillary Anterior Ridge
AKIYAMA Akemi, YAWAKA Yasutaka, HARADA Rie, OSANAI Masakazu, AMEMIYA Akira, OGUCHI Haruhisa, 小児歯誌, 36, 1, 144, 153, 1998
Japanese - Histological Study of the Exposed Root Apex in the Oral Cavity in Human Deciduous Incisors with Apical Periodontitis
YAWAKA Yasutaka, OSANAI Masakazu, AKIYAMA Akemi, KOJIMA Hiroshi, OGUCHI Haruhisa, 『小児歯科学雑誌』, 35, 5, 812, 820, 1997
Japanese - Crown Exposure and Traction of Inverted and Unerupted Maxillary Central Incisors with Respect to the Starting Line of Treatment : Three Cases with Different Developmental Stages of the Root
KOJIMA Hiroshi, MIURA Mari, YAWAKA Yasutaka, OGUCHI Haruhisa, The Japanese Journal of Pediatric Dentistry, 34, 1, 259, 268, 1996
The development of the root subsequent to the crown exposure and traction was clinically evaluated in three cases of inverted and unerupted maxillary central incisors for which the developmental stages of the root were regarded as R 3/4, R 1/2 and R 1/4, respectively at the initiation of the treatment according to the classification of Moorrees et al.
In the case the treatment procedure was started at R 3/4, the root of the impacted upper central incisor was found to have already bent labially from X-ray exmination before treatment. The development of the root continued in the abnormal direction, so that the solid swelling of the mucous membrane due to the projection of the root apex was recognized after the procedure had been completed.
In the case the treatment procedure was started at R 1/2, the development of the root continued during the treatment in the same manner as the contralateral tooth with slight bending at the middle portion of the root.
In the case the treatment procedure was started at R 1/4, the development of the root continued thereafter in the same manner as the contralatelal tooth without root bend.
These observations indicated that the vitality and activity of the pulp tissue and the root forming tissue was not inhibited during the treatment procedure of inverted and unerupted maxillary central incisors with imcomplete root formation. It was also suggested that the eary treatment at or before the initial stage of root bend in these teeth resulted in successful guidance of eruption avoiding the bent and dwarfed root formation., The Japanese Society of Pediatric Dentistry, Japanese - The process of physiological root resorption : Relationship between resorbed root volumes and resorption of coronal pulp chamber wall
YAWAKA Yasutaka, OSANAI Masakazu, WAKITA Minoru, OGUCHI Haruhisa, Pediatric Dental Journal, 6, 1, 107, 113, 1996
English
Books and other publications
- 歯科衛生士講座 障害者歯科学 第3版
八若保孝, 第7章 コミュニケーションの確立と行動調整
八若保孝, 永末書店, Feb. 2022, 9784816014031, [Joint translation] - 小児歯科学ベーシックテキスト第2版
八若保孝, 第20章 心身障害児への歯科的対応
永末書店, Mar. 2019, 9784816013607, [Joint work] - 小児歯科学第5版
八若保孝, 第7章 小児期の歯・歯周組織の特徴
医歯薬出版株式会社, Dec. 2017, 9784263458075, [Joint work] - スペシャルニーズデンティストリー障害者歯科第2版
八若保孝, Ⅲ編 スペシャルニーズのある人の歯科医療 Ⅲ予防法 3-不正咬合
医歯薬出版株式会社, Feb. 2017, 9784263458013, [Joint work] - 小児歯科学 第4版
医歯薬出版株式会社, 2011 - 治療4月増刊号 デキる医師の紹介・逆紹介スキル99
南山堂, 2010 - スペシャルニーズデンティストリー障害者歯科
医歯薬出版株式会社, 2009 - 日本歯科医学教育学会 歯科医学教育白書作成委員会(編),日本歯科医学教育学会雑誌別冊 歯科医学教育白書2005年度版(2003~2005年)
日本歯科医学教育学会(財:口腔保健協会), 2006 - 乳歯列期における外傷歯の診断と治療<木村光孝,高木裕三,香西克之,朝田芳信(編)>
クインテッセンス出版, 2005
Affiliated academic society
Research Themes
- Control of complicated root canal system of primary teeth: Reproduction of resorbed part of outer root surface
Grants-in-Aid for Scientific Research
01 Apr. 2024 - 31 Mar. 2027
八若 保孝, 中村 光一
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 24K13167 - 生活歯髄切断材料に対する抗酸化アミノ酸の応用~強アルカリによる歯髄刺激からの脱却
科学研究費助成事業
01 Apr. 2022 - 31 Mar. 2025
中村 光一, 阿部 薫明, 八若 保孝
日本学術振興会, 基盤研究(C), 北海道大学, 22K10259 - Hg・Pb・Al曝露は非認知及び前頭葉機能発達に影響するか?-思春期までの追跡-
科学研究費助成事業
01 Apr. 2020 - 31 Mar. 2024
草薙 恵美子, 星 信子, 高橋 義信, 中村 光一, 八若 保孝, 森口 佑介, 高橋 文
本研究の目的は、胎児・幼児・学童・思春期の各時期の金属曝露及び家庭環境等が急激な心理的変化の生じる思春期の子どもの心理・脳機能・運動発達に与える影響を縦断的に検討することである。
学童期紙面調査に回答した国内5地域271家庭に母親及び子ども用の調査票を郵送した。母親用調査票では、思春期気質質問紙「EATQ-R(Parent)」日本語版、「日本語版家族機能測定尺度」(FACES Ⅲ)、「子どもの強さと困難さアンケート(SDQ)」(4~17歳用/親記入用)の質問項目、及び食品摂取頻度、家庭の経済状況等について尋ねた。子どもの自記式調査票では、「EATQ-R(Kid)」日本語版、SDQ(11~17歳用/自己記入用)、FACES Ⅲからの質問項目について尋ねた。171名の母親及び167名の子どもから回答を得た。
SDQの子どもの「総合的困難さ」の母親評定値と子どもの自己評定値の相関はr= 0.54であった。重回帰分析により学童期の養育及び気質の思春期「総合的困難さ」への影響を検討した結果、母親による評定では、養育変数と性の調整後、外向性・高潮性(ES)とエフォートフル・コントロール(EC)が困難さを減少させ、否定的情動性(NA)は困難さを増加させることがわかった。子どもの評定した「総合的困難さ」では、ESは有意ではなく、ECの影響度も半減したが、養育尺度の感情的領域が有意となり、子どもの感じる困難さには養育行動が影響していることが確かめられた。
学童期の子どもの毛髪中金属をICP-QQQにより測定した。毛髪処理及び測定の妥当性は標準試料(Human Hair:NIES CRM No.3)を用いて検討した。幼児期で問題のみられたアルミニウムの回収率は、灰化方法を変更することで概ね満足のいく回収率となった。子どもの毛髪中の鉛やマンガン等の金属の含有量は標準試料の毛髪濃度よりも低かった。
日本学術振興会, 基盤研究(B), 國學院大學北海道短期大学部, 20H01664 - 複雑な乳歯根管系の制御-歯根外部吸収への修復機構の誘導と歯根安定の獲得-
科学研究費助成事業
01 Apr. 2020 - 31 Mar. 2023
八若 保孝, 中村 光一
根管治療において、根管内壁に生じるスミア層の除去が重要で、根管貼薬剤の効果を根管、根管内壁、象牙細管を通しての根管歯質、歯根外表面へ有効に拡散させることができる。これまでに、根管洗浄として、有機質溶解作用のある次亜塩素酸ナトリウムを使用した超音波洗浄が、乳歯ではスミア層除去に有効であること、永久歯では、硬組織脱灰作用のあるEDTAを使用した超音波洗浄を加えることで、適切なスミア層除去ができることを示すことができた。
適切なスミア層除去により、根管貼薬剤である水酸化カルシウム製剤の効果が歯根外表面にまで拡散することが示され、前述した根管洗浄法が、複雑な乳歯根管系の制御の最も重要な点であることが把握された。
根尖性歯周炎の治療は、炎症のコントロールと病的歯根吸収のコントロールの両面での対応が必要である。根尖性歯周炎は、超音波を用いた根管洗浄により貼薬剤の効果が有効に発揮され、炎症のコントロールの確実性が増加した。歯根吸収においては、前述の有効な根管洗浄により、吸収を示す歯根外表面へ象牙細管を経由した水酸化カルシウムのアルカリ性の拡散が生じる。これにより、酸性環境が必要な歯根吸収部を中和させることができ、歯根吸収抑制の可能性が高くなる。事実、臨床においてこの方法を行うことで、多くの症例で歯根吸収を止めることができた。
歯根外表面の吸収部については、これまでの組織学的検索で、セメント質添加による形態的修復が生じることがあることが報告されている。しかし、どのような環境下で、なにがトリガーとなって、セメント質添加が生じるのかは解明されていない。細胞培養系および実験動物系の2系統を用いて、この点を明らかにする。
日本学術振興会, 基盤研究(C), 北海道大学, 20K10197 - Making pulp capping materials using epigallocatechin-3-gallate
Grants-in-Aid for Scientific Research
01 Apr. 2019 - 31 Mar. 2022
Nakamura Koichi
After adding LPS and HEMA stimulation to RAW264.7 cell, and performing WST-8 assay, EGCG did not affect it for cell proliferation. EGCG reduced PGE2 production induced by LPS and HEMA. As the result of pulpotomy, EGCG attenuated recalcification.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 19K10374 - Do mercury and lead exposure effect development of psychological and frontal lobe function?: longitudinal study from early to middle childhood
Grants-in-Aid for Scientific Research
01 Apr. 2017 - 31 Mar. 2021
Kusanagi Emiko
We investigated the development of psychological, motor, and brain activities as well as food intake in elementary school children whose hair metal concentrations were measured in early childhood. In addition, the levels of metal exposure during the fetal and infancy periods were determined by measuring the concentration of metals in the deciduous teeth enamel of children using ICP-MS. Early childhood exposure to mercury had an adverse effect on the development of children's temperament in school age. Aluminum and lead had an adverse effect on the development of boys’ fine motor behavior in school age. However, there was no effect of metal exposure on brain function development in school age. We found that the nutritional intake of children was associated with the development of throwing ability and cognitive flexibility. Regarding the factors affecting the amount of metal in hair in early childhood, it was revealed that yogurt intake reduced the exposure levels of lead and aluminum.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Kokugakuin University Hokkaido Junior College, 17H02197 - Control of complicated root canal system of primary teeth: Clarification of reliable method for root resorption control and repair mechanism on resorbed part
Grants-in-Aid for Scientific Research
01 Apr. 2017 - 31 Mar. 2020
YAWAKA YASUTAKA
Regarding the root canal treatments, it was showed that the important factors of the control of complicated root canal system of primary teeth were the root canal irrigation with ultrasonic and the root canal medication by calcium hydroxide (Ca(OH)2).
We constructed a root resorption model in rat molar in animal experiment, and observed histologically the effects of Ca(OH)2 on root resorption. The effects of Ca(OH)2 showed inhibition of root resorption and occurrence of cementum deposition. We think cementum deposition is one of repair mechanisms on resorbed part.
We could construct a root resorption model in cell culture. But we do not reach the step as to investigate effects of Ca(OH)2 due to bad reproducibility.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 17K11951 - Control of complicated root canal system of primary teeth: Examination on ion diffusion of calcium hydroxide and effectiveness of outer root resorption control
Grants-in-Aid for Scientific Research
01 Apr. 2013 - 31 Mar. 2016
YAWAKA YASUTAKA, NAKAMURA Koichi
Removal of smear layer and opening of dentinal tubules on root canal surface with root canal irrigation is important factor on good convalescence of root canal treatment. Regarding the root canal irrigation, it was showed that combination of EDTA and NaOCl with ultrasonic was effective in removing the smear layer on permanent teeth, and NaOCl with ultrasonic was effective on primary teeth.
This study investigated ion diffusion from calcium hydroxide (Ca(OH)2) through the root dentin of extracted human teeth. It was suggested that the smear layer removal and opened dentinal tubules by root canal irrigation with ultrasonic was valid for the alkaline diffusion from Ca(OH)2 to outer root surface. Moreover, it was showed that calcium ion diffused to the outer root surface from root canal. Therefore, it was suggested that the good condition with smear layer removal and opened dentinal tubules by root canal irrigation facilitated the effectiveness of Ca(OH)2 as the root canal medication.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 25463164 - Collection and Construction of database for physiological and physical support of children
Grants-in-Aid for Scientific Research
01 Apr. 2012 - 31 Mar. 2016
FUJIWARA Taku, HOSHINO Tomonori, NISHIGUCHI Miyuki, HIDAKA Kiyoshi, ASADA Yoshinobu, YAMASAKI Youichi, KAMASAKI Youko, MOTOMURA Youichi, SAITOH Kan, KARIBE Hiroyuki, YAWAKA Yasutaka, HAYASAKI Haruaki, SATOH Kyouko, SHINTANI Seikou, HIRATA Souichirou
The purpose of this study is to analyze the data of patients’ background using machine learning method and to develop an application that could output helpful information. We also tried to construct a new system that will enable to continuously collect and utilize these data using tablet. We included data collection system of dental trauma.
Data collection system was completed. We will continue data collection using this system.
We tried to make decision tree from questionnaire of the mother class using application Weka (Machine Learning Group at the University of Waikato, New Zealand) . Several decision trees were generated, but we could not obtain proper decision trees according with the conventional theory. Since the contents of the sheet were slightly different at each clinic, missing values were likely to influence the analysis. A unified questionnaires style would be necessary. In addition, selection of the objective variable should be more important.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Nagasaki University, 24390463 - Control of complicated root canal system of primary teeth: For good results of root canal treatment with apical periodontitis
Grants-in-Aid for Scientific Research
2010 - 2012
YAWAKA Yasutaka
Root canal enlargement and preparation makes the smear layer on the root canal wall. The aim of this study was to evaluate the influence of endodontic irrigation associated with removal of the smear layer. EDTA with ultra sonic or combination of EDTA and NaOCl with ultra sonic was effective in removing the smear layer on permanent teeth. NaOCl with ultra sonic was effective in removing the smear layer on primary teeth. It was suggested that root canal irrigation with ultra sonic was valid for the alkaline diffusion from calcium hydroxide.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 22592276 - An epidemiological survey about the prevalence of congenitally missing permanent teeth of Japanese children
Grants-in-Aid for Scientific Research
2007 - 2008
YAMASAKI Youichi, IWASAKI Tomonori, HAYASAKI Haruaki, SAITHO Issei, TOKUTOMI Junko, YAWAKA Yasutaka, INOUE Mitsuko, ASADA Yoshinobu, TAMURA Yasuo, KANOMI Ryuzo, MAKI Kenshi, YOSHIHARA Toshihiro, FUNATSU Takahiro, TESHIMA Yoko, UESATO Chika, YAMASHITA Kazue, IDE Masamichi, KURIYAMA Tihiro, MUKAI Ayako, KONDO Tsuguko, KATOH Mikio, WATANABE Kyoko, FUJITA Yuuko, HASEGAWA Hiroko, INADA Emi
北海道大学、昭和大学、鶴見大学、朝日大学、大阪歯科大学、九州歯科大学、鹿児島大学の7大学における附属病院小児歯科と調査協力施設において、エックス線写真を使用した永久歯の先天性欠如に関する疫学調査を行った。対象者は、資料採得時の年齢が永久歯胚の確認が可能となる7歳以上の小児とした。調査対象者総数は15, 544名(男子7, 502名、女子8, 042名)で、永久歯の先天性欠如者数は1, 568名、発現頻度は10.09%であった
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Kagoshima University, 19390532 - Development of self healing materials with remineralization(Bioglass for dental materials)
Grants-in-Aid for Scientific Research
2006 - 2007
HASHIMOTO Masanori, YAWAKA Yasutaka, KAGA Masayuki, HASHIMOTO Masanori
A finding in this study was that crystal formation (approximately 10 μm in diameter) was a common feature of some fluoridated adhesive resins, where were separated by a standardized interfacial gap between teeth and cured materials. This crystal growth was also found in bioglass (Na_2-CaO-SiO_2-P_2O_5) -containing adhesive resins after several months of water storage. The mechanical properties of resin adhesives are completely reduced by bioglass addition. The decreasing amount of bioglass addition for adhesives prevents a reduction of mechanical property of materials but it reduces an amount of ion releasing for remineralization. The reduction of mechanical property may induced by crystal growth formation due to simultaneous response between bioglass and water. In theory, there are one possibility for increasing the surface area of bioglass per unit, and thus making them more active. An future approach may be simply to decrease glass particle size (nano-sized bioglass), and thus increase the ion exchange surface of glass and surrounding liquid, and prevent mechanical property decreasing for clinical use.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), 18592226 - 遺伝子治療による新しい歯根吸収制御法の開発
科学研究費助成事業
2003 - 2003
小口 春久, 吉村 善隆, 八若 保孝, 加我 正行
骨形成・骨吸収の遺伝子治療が考えられている現在、病的あるいは非生理的な「歯根吸収の制御」を遺伝子治療という観点から考えることは、新しい研究分野の展開につながる将来性のある研究の第一歩と考える。破骨細胞は骨吸収を担う多核細胞であり、単球・マクロファージ系細胞の前駆細胞から分化することが知られている。予備実験の結果から、今回我々は、炎症性サイトカインの1つであるマクロファージ遊走阻止因子(MIF)が、破骨細胞分化過程にどのような影響を及ぼすかについて検討を行った。マウス骨芽細胞様細胞(MC3T3-E1細胞)とマウス骨髄細胞との共存培養系によって破骨細胞を誘導し、酒石酸耐性酸性ホスファターゼ(TRAP)活性陽性細胞の出現数、破骨細胞分化因子(RANKL)の発現量、破骨細胞抑制因子(OPG)の産生量および象牙質切片を用いた硬組織吸収能についてMIFの影響を調べた。その結果、TRAP陽性多核細胞の出現数は、MIF濃度に依存して減少することが判明した。一方、MC3T3-E1細胞におけるRANKLの発現およびOPGの産生に、MIFの影響は確認されなかった。TRAP陽性細胞1個中に含まれる核数の分布を調べたところ、MIF作用群ではコントロールと比較し、多核化が抑制されていることが明らかになった。また、象牙質切片上に形成された吸収窩を観察したところ、MIF作用群では形成された吸収窩の大きさが明らかに小さかった。以上の結果より、MIFは骨芽細胞に作用するよりも、むしろ、分化・成熟過程にある破骨細胞の融合過程を阻害することで、成熟した破骨細胞の出現を抑制しているものと考えられ、これらを基盤とすることで、単球・マクロファージ系細胞の破骨細胞前駆細胞もしくは骨髄細胞への遺伝子治療による新しい歯根吸収制御法開発の礎が可能と考えられる。
日本学術振興会, 萌芽研究, 北海道大学, 15659489 - Analysis of pathological root resorption of deciduous teeth and establishment for the treatment
Grants-in-Aid for Scientific Research
1999 - 2001
OGUCHI Haruhisa, HASEGAWA Tomokazu, YAWAKA Yasutaka, KAGA Masayuki
SEM observation of root surface of deciduous teeth surface pathologically resorted was done. Exudates from root cannal were analyzed by PCR detection. Moreover, periodontal ligament cells were cultured to study the moleculars concerned with osteoclast differentiation.
1. By SEM observation of deciduous root with severe periodontitis, numerous bacteriums were observed in the root canals or on the root surfaces. However, no bacterium was there in the dentin tubules of apical region. Pathological root resorption was observed in wide region, but there was no odontoclasts. The pathological root resorption was advanced irregularly in the resion and a lot of resorbed lacunae were observed just like a worm-eaten shape. Therefore, it was thought that the pathological root resorption was greatly affected with bacteriums and their products.
2. To determine the bacterial outcome of apical periodontitis in deciduous teeth, Intra-canal exudates were absorbed with sterilized paper points. The suspensions with exudates were analyzed by PCR. The result was that bacterial 16s rDNA was detected in 12 cases out of 16cases tested. Bacterial analysis by PCR is effective to clarify the bacterial species and treatment for periodontitis.
3. Periodontal ligament (PDL) cells produce ten-fold osteoprotegerin (OPG) compared with osteoblasts and gingival cells. It suggests that osteoclast differentiation is depressed by OPG from PDL cells. It appears that PDL is not only connective tissue between a tooth and alveolar bone but also protection of bone and teeth resorption from osteoclast. We think that it is possible to depress for pathological root pesorption with canal root drag containing OPG.
These results suggested that complete root canal rinsing and disinfection of root canal are an effective treatment of pathological root resorption. Detection of bacteria species and for the treatment is needed. Moreover, induction of osteoprotegrin was suggested for the new treatment in the apical root inflammation.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), HOKKAIDO UNIVERSITY, 11470445 - Histological study of pathological root resorption in human deciduous teeth with apical periodontitis.
Grants-in-Aid for Scientific Research
1997 - 1999
YAWAKA Yasutaka, KAGA Masayuki
The purpose of this study was to examine a different root resorption process on the root dentin with apical periodontitis or on sound root dentin.
1. The region of the root apex with severe apical periodontitis in human deciduous teeth was observed by light and transmission electron microscopy. Root dentin and original cementum had a severe irregular caved surface due to pathological root resorption. Cementum had partial!y deposited on the caved dentin and original cementum surfaces. The structure of deposited cementum was very different from that of the original cementum. It was thought that partial repair mechanisms such as cementum deposition are affected by the surrounding environment of the root.
2. Root dentin slices were prepared from human deciduous teeth with apical periodontitis (group p) or sound human deciduous teeth (group n, control). Cell suspension of bone marrow from the femur of mice in α MEM was seeded on the dentin slices and incubated. After incubation, specimens were removed and fixed, and then observed for tartrate-resistant acid phosphatase (TRAP) activity. The number of TRAP-positive cells on the dentin was calculated by light microscopic observation. TRAP-positive cells were observed in all dentin slices. There were no significant differences between group p and group n on the number of TRAP-positive cells by Mann-Whitney test. The results suggested that root dentin with apical periodontitis was resorbed by cultured osteoclasts It was thought that enviromental factors in root circumferences had a greater effect than does the condition of root dentin on pathological root resorption.
3. The root dentin slices of group p and group n were embedded in rats subcutaneous tissue. The dentin slices of both groups were surrounded by fibrous connective tissue are inflammatory cells and partially resorbed by multinuclear giant cells. However, the resorption was slight. There were no differences between the both groups on the condition of the dentin slices. It was thought that the condition of root dentin had few effect on pathological root resorption.
Therefore, it was suggested that enviromental factors in root circumferences had a great effect on patholagical root resorption.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), HOKKAIDO UNIVERSITY, 09672089 - 乳歯列不正咬合に関する形態学的および機能学的研究
1992
Competitive research funding - The molphological and functional study of malocclusion in primary dentition
1992
Competitive research funding - 乳歯の生理的歯根吸収および病的異常吸収に関する組織学および分子生物学的研究
1989
Competitive research funding - Histological and molecular biological study of physiological and pathological root resorption in primary teeth.
1989
Competitive research funding