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Moriyama Yasuko Last modified date:2022.06.09

Assistant Professor / Division of Oral Rehabilitation
Department of Dental Science
Faculty of Dental Science

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 Reseacher Profiling Tool Kyushu University Pure
Academic Degree
Ph.D. in dentistry
Country of degree conferring institution (Overseas)
Field of Specialization
Section of Implant and Rehabilitative Dentistry
Total Priod of education and research career in the foreign country
Research Interests
  • Influence of osteoporosis on bone around osseointegrated dental implants.
    keyword : osteoporosis, peri-implant bone remodeling, osteocyte, mechanical stress
  • Association between peri-implant bone remodeling and deterioration of bone quality.
    keyword :  bone quality, implant, bone modeling, osteocyte
  • The use of statin for vertical bone augmentation.
    keyword : statin, bone augmentation
  • A Histological Evaluation for Guided Bone Regeneration with a PLGA/statin Membrane Applied to Bone Defects.
    keyword : statin, PLGA, DDS, bone augmentation
  • The effect of micro vibration on the bone healing of rat extraction socket.
    keyword : micro vibration, tooth extraction socket, bone
  • Bone reaction of peri-implant caused by mechanical stress, in vivo and in vitro studies.
    keyword : implant, mechanical stress, osteocyte
  • Peri-implant osteogenesis is promoted by the local application of statin.
    keyword : Local application of statin, Implan, bone formation
Academic Activities
1. Xi Chen, Yasuko Moriyama, Yoko Takemura, Maho Rokuta, Yasunori Ayukawa., Influence of osteoporosis and mechanical loading on bone around osseointegrated dental implants: A rodent study, Journal of the Mechanical Behavior of Biomedical Materials, 10.1016/j.jmbbm.2021.104771, 123, 104771, 2021.08, This study aimed to evaluate the influence of estrogen deficiency and mechanical loading on bone around osseointegrated dental implants in a rat jaw model. The maxillary right first molars of 36 rats were extracted. One week later, the rats were divided into an unloaded group and a loaded group; short head implants and long head implants were inserted respectively. Nine weeks after implantation, the rats were further subjected to ovariectomy (OVX) or sham surgery. All animals were euthanized 21 weeks after OVX. Micro-computed tomography, histological and histomorphometrical evaluation were undertaken. Systemic bone mineral density and bone volume fraction decreased in OVX groups compared with the sham controls. Histomorphometrical observation indicated that unloaded OVX group showed significantly damaged osseointegration and bone loss versus the loaded OVX group. Both the bone density (BD) inside the peri-implant grooves and the percentage of bone-to-implant contact (BIC) were lower in the OVX groups than in the sham-surgery groups, although mechanical loading increased the BIC and BD in the loaded OVX group compared with the unloaded OVX group. An increased number of positive cells for tartrate-resistant acid phosphatase was observed in the OVX groups versus the sham controls. The percentage of sclerostin-positive osteocytes was lower under loaded compared with unloaded conditions in both the OVX groups and the sham controls. In conclusion, estrogen deficiency could be a risk factor for the long-term stability of osseointegrated implants, while mechanical loading could attenuate the negative influence of estrogen deficiency on bone formation and osseointegration..
2. Haomiao Zhang, Yasuko Moriyama, Yasunori Ayukawa, Yunia Dwi Rakhmatia, Yoko Tomita, Noriyuki Yasunami, Kiyoshi Koyano., Generation and histomorphometric evaluation of a novel fluvastatin-containing poly(lactic-co-glycolic acid) membrane for guided bone regeneration., Odontology, 2018.06, The purpose of this study was to evaluate the effects of a poly(lactic-co-glycolic acid) (PLGA) membrane containing fluvastatin on bone regeneration at bone defects in rat calvaria and tibia for possible use as a guided bone regeneration (GBR) membrane. PLGA and fluvastatin-containing PLGA (PLGA-fluvastatin) membranes were prepared and mechanical properties were evaluated. Standardized bony defects were created in rat calvaria and the right tibia, and covered with a PLGA or PLGA-fluvastatin membrane. Bone regeneration was evaluated using image analysis based on histologic examination. At 4 and 8 weeks after membrane implantation, the PLGA-fluvastatin group displayed enhanced new bone formation around the edge of the defect compared with the PLGA membrane group in the calvarial model. Thick bone regeneration was observed in tibia defect sites in the PLGA-fluvastatin membrane group. These results suggest that the PLGA-containing fluvastatin membrane prepared in this study may potentially be used as a GBR membrane..
3. Yasuko Moriyama, Yasunori Ayukawa, Yoichiro Ogino, Ikiru Atsuta, Mitsugu Todo, Yoshihiro Takao, Kiyoshi Koyano., Local application of fluvastatin improves peri-implant bone quantity and mechanical properties: A rodent study., Acta Biomaterialia, 6, 4, 1610-1618, 2010.04, Statins are known to stimulate osteoblast activity and bone formation. This study examines whether local application of fluvastatin enhances osteogenesis around titanium implants in vivo. Ten-week-old rats received a vehicle gel (propylene glycol alginate (PGA)) or PGA containing fluvastatin (3, 15, 75 or 300 μg) in their tibiae just before insertion of the implants. For both histological and histomorphometric evaluations undecalcified ground sections were obtained and the bone–implant contact (BIC), peri-implant osteoid volume and mineralized bone volume (MBV) were calculated after 1, 2 and 4 weeks. Using the same models mechanical push-in tests were also performed to evaluate the implant fixation strength. After 1 week the MBV and push-in strength were significantly lower in the 300 μg fluvastatin-treated group than in the other groups (P < 0.01). At 2 weeks, however, the BIC and MBV were both significantly higher in the 75 μg fluvastatin-treated group than in the non-fluvastatin-treated groups (P < 0.01). Similar tendencies were observed at week 4. Furthermore, the data showed a good correlation between the MBV and the push-in strength. These results demonstrate positive effects of locally applied fluvastatin on the bone around titanium implants and suggest that this improvement in osseointegration may be attributed to calcification of the peri-implant bone..
4. Yasuko MORIYAMA, Yasunori AYUKAWA, Kenichi KABAMURA, Yasuyuki MATSUSHITA, Masafumi KIHARA, Yoshihiro TSUKIYAMA,Mitugu TODO, Yoshihiro TAKAO, Kiyoshi KOYANO, The Alternation of Peri-Implant Bone Response Exposed to Static Lateral Load, Journal of Biomechanical Science and Engineering , 4, 3, 326-335, 2009.07.
5. Yasuko Moriyama, Yasunori Ayukawa, Yoichiro Ogino, Ikiru Atsuta, Kiyoshi Koyano, Topical application of statin affects bone healing around implants, Clinical Oral Implants Research, 19, 600-605, 2008.01.
1. The purpose of this study was to evaluate the effects of an injectable composite made up of calcium sulfate (CAS), fluvastatin (FS) and atelocollagen on bone augmentation in rats. Porous structures and the compressive strength of composites were evaluated. The cumulative
release kinetics of FS were determined in vitro by a spectrophotometer. To observe bone regeneration in vivo, five different materials (normal saline; atelocollagen gel only; composite of CAS and atelocollagen; composite containing 0.5% FS; and composite containing 1.0% FS) were injected in extraction sockets and on the crania of rats. Micro-computed tomography (micro-CT) and histological evaluation were performed after 2, 4, and 8 weeks of healing time. The composites had high porosity (greater than 55%). FS kept a slow and stable release
for >30 days. In vivo results demonstrated that, more new bone was formed in the FS groups compared with other groups, both bone mass and bone density had prominent increased in maxillae and crania. Resorption of the composite was also observed for cranial tissues. In conclusion, this composite can be applied percutaneously, without any incision. It has excellent properties with replaceability into bone and anabolic effects for bone formation, as well as a drug delivery system for bone formation..
Membership in Academic Society
  • International Association for Dental Research
  • Synergetic effect of sandblasted and acid-etched surface and statin on peri-implant Osteogenesis.
  • Topical application of fluvastatin affects the bone healing around implants.