Yohei Jinno

Publications (3)12.43 Total impact

• Article: Evaluations of epithelial sealing and peri-implant epithelial down-growth around "step-type" implants.

  Ikiru Atsuta, Yasunori Ayukawa, Yoichiro Ogino, Yasuko Moriyama, Yohei Jinno, Kiyoshi Koyano
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  ABSTRACT: Implant designs that can stimulate and integrate with an epithelial wound-healing process may significantly enhance the efficacy of dental implants. Here, we evaluated the potential of "step-type" implant systems to improve the sealing between the peri-implant epithelium (PIE) and the implant surface, and investigated the effect of implant structure on PIE down-growth. Right maxillary first molars were extirpated from rats and implanted with either a straight-type or a step-type implant varying in step height and/or width (N(s): 0.8 mm height, 0.1 mm width; W(s): 0.8 mm height, 0.2 mm width; H(s): 0.4 mm height, 0.1 mm width). Maxillae were harvested at various time points over 16 weeks to evaluate laminin-5 distribution as an indicator of wound healing and PIE formation, horse-radish peroxidase (HRP) penetration as a measurement of epithelial sealing, and PIE down-growth formation. In all implant models, the PIE formed from the oral sulcular epithelium and spread apically along the implant surface. In the W(s) group, HRP penetration was detected only in the coronal region of the PIE at 4 weeks, whereas in the straight-type, it was observed in the apical region and the connective tissue. At 16 weeks, the W(s) implants exhibited markedly less PIE down-growth than the Con, N(s) or H(s) implants, and were equivalent to that observed in natural teeth. The step-type implant system may have the potential for improving epithelial sealing at the tissue-implant interface, as well as reducing apical PIE down-growth, thus enhancing dental implant efficacy.
  Clinical Oral Implants Research 04/2011; 23(4):459-66. · 2.51 Impact Factor
• Article: The effect of a single remote injection of statin-impregnated poly (lactic-co-glycolic acid) microspheres on osteogenesis around titanium implants in rat tibia.

  Tomohiro Masuzaki, Yasunori Ayukawa, Yasuko Moriyama, Yohei Jinno, Ikiru Atsuta, Yoichiro Ogino, Kiyoshi Koyano
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  ABSTRACT: The aim of this study was to evaluate the effects of newly developed injectable poly (lactic-co-glycolic acid) (PLGA) microspheres containing fluvastatin on osteogenesis around titanium implants in the rat tibia. After confirmation of the sustained-release profile of fluvastatin from the microspheres by an in vitro assay, the microspheres were administered to the back skin of the rats by a single transdermal injection. At 2 and 4 weeks after the implant surgery, the fluvastatin groups showed enhanced new bone formation around the titanium implants without any influence on the serum biochemistry. In addition, the fluvastatin groups showed increased three-point bending strengths of their femurs. The results of this study indicate that a single remote injection of PLGA/fluvastatin microspheres safely and successfully stimulated bone formation around titanium implants and increased the mechanical properties of bone.
  Biomaterials 04/2010; 31(12):3327-34. · 7.40 Impact Factor
• Article: Vertical bone augmentation with fluvastatin in an injectable delivery system: a rat study.

  Yohei Jinno, Yasunori Ayukawa, Yoichiro Ogino, Ikiru Atsuta, Yoshihiro Tsukiyama, Kiyoshi Koyano
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  ABSTRACT: HMG-CoA reductase inhibitors (statins) are widely used for hyperlipidemia. Previous studies demonstrate that statins stimulate bone morphogenetic protein-2 (BMP-2) expression and lead to bone formation. The aim of this study was to evaluate whether percutaneously injected statin with a novel statin delivery system achieved vertical bone augmentation. As experimental groups, atelocollagen-alpha-tricalcium phosphate (alphaTCP) composites containing 3.3 mg (low dose) or 6.7 mg (high dose) of fluvastatin were injected (one shot) subcutaneously over the calvarial periosteum of rats. The animals were then sacrificed 1, 2, and 4 weeks after injection. Vertically augmented bone was assessed by histomorphometric procedures, i.e., by measuring new bone thickness (NBT) and bone density (BD). In control groups, no newly formed bone could be seen over the calvarial bone. In the experimental groups, in contrast, a large amount of newly formed bone could be seen over the preexisting calvarial bone. The newly formed bone was seen to be in direct contact with the preexisting bone. During the entire observation, significant NBT was observed in the experimental groups (P<0.05). At the final stage of observation (4 weeks), NBT was 66.7% (low-dose group) and 59.7% (high-dose group), while they were from 1% to 16.3% in the control groups. In the experimental groups, BD significantly increased in a time-dependent manner. Percutaneously applied fluvastatin (one shot) with a composite of alphaTCP and collagen has great potential to augment the height of the bone.
  Clinical Oral Implants Research 03/2009; 20(8):756-60. · 2.51 Impact Factor