Biomedical subjects

Yasuhiro Okazaki

Publications and source records attributed to Yasuhiro Okazaki.

4 recordsLinked to original sources

PubMed2005

Clinical case reports of injectable tissue-engineered bone for alveolar augmentation with simultaneous implant placement.

This clinical study was undertaken to evaluate the use of tissue-engineered bone, mesenchymal stem cells, platelet-rich plasma, and beta-tricalcium phosphate as grafting materials for maxillary sinus floor augmentation or onlay plasty with simultaneous implant placement in six patients with 3- to 5-mm alveolar crestal bone height. All 20 implants were clinically stable at second-stage surgery and 12 months postloading. A mean increase in mineralized tissue height of 7.3+/-4.6 mm was evident when comparing the pre- and postsurgical radiographs. Injectable tissue-engineered bone provided stable and predictable results in terms of implant success.

Absorbable Implants↗

PubMed2003

Bone regeneration following injection of mesenchymal stem cells and fibrin glue with a biodegradable scaffold.

AIM: The purpose of this study was to determine whether a combination of fibrin glue, beta-tricalcium phosphate as a biodegradable (beta-TCP) and mesenchymal stem cells would provide three-dimensional templates for bone growth resulting in new bone formation at heterotopic sites in the rat with plasticity. MATERIAL AND METHODS: Growing stem cells and developing matrices, explanted from the rat femur, were fragmented and mixed with fibrin glue in a syringe. The cells/beta-TCP fibrin glue admixtures were injected into the subcutaneous space on the dorsum of the rat. RESULTS: Eight weeks after implantation, gross morphology revealed a pearly opalescence and firm consistency. Histological inspections showed newly formed bone structures in all admixtures, but none in the control groups when only fibrin glue and beta-TCP were injected. Osteopontin, a protein important in bone development, was identified by using antibodies in all cells/beta-TCP fibrin glue admixtures. CONCLUSION: Mesenchymal stem cells/beta-TCP fibrin glue admixtures can result in successful bone formation. This technique holds the promise of a minimally invasive means of generating autogenous bone to correct or reconstruct bony defects.

Animals↗

PubMed2002

Tissue-engineered bone using mesenchymal stem cells and a biodegradable scaffold.

Bone marrow has been shown to contain a population of rare cells capable of differentiating to the cells that form various tissues. These cells, referred to as mesenchymal stem cells (MSCs), are capable of forming bone when implanted ectopically in an appropriate scaffold. The aim of this study was to investigate the potential of a new beta-tricalcium phosphate (beta-TCP) as a scaffold and to compare the osteogenic potential between beta-TCP and hydroxyapatite (HA). The beta-TCP and HA loaded with MSCs were implanted in subcutaneous sites and harvested at 1, 2, 4, and 8 weeks after implantation for biochemical and histological analysis. Biochemically, in both beta-TCP and HA composites, the alkaline phosphatase activity in the composites could be detected and was maintained at a high level for 8 weeks. In the histological analysis, active bone formation could be found in both the beta-TCP and HA composites. These findings suggest that beta-TCP could play a role as a scaffold as well as HA. The fabricated synthetic bone using biodegradable beta-TCP as a scaffold in vivo is useful for reconstructing bone, because the scaffold material is absorbed several months after implantation.

Absorbable Implants↗

PubMedDate not supplied

Clinical application of zygomatic implants for rehabilitation of the severely resorbed maxilla: a clinical report.

PURPOSE: A zygomatic implant can be an effective device for rehabilitation of the severely resorbed maxilla. If zygomatic implants are used, onlay bone grafting or sinus augmentation would likely not be necessary. Where an anterior onlay bone graft is required, extension of the graft in the posterior region could be reduced. The results of the application of zygomatic implants in 9 patients and clinical evaluation of this therapy are reported. MATERIALS AND METHODS: Nine patients received a total of 15 zygomatic implants. Six to 8 months elapsed for healing before second-stage surgery was performed. Six months after prosthetic treatment, patients' opinions were solicited by means of a questionnaire. RESULTS: No implant was removed at the time of abutment connection surgery or during the follow-up period. In many cases, the zygomatic implant platform was located palatal to the alveolar ridge. However, no patients complained of any continuing speech impediment following superstructure fabrication. Computed tomograms taken before implant placement and 6 months after implant placement showed no sign of sinusitis in any patient. DISCUSSION: The zygomatic implant allows shorter treatment time and hospitalization. However, there can be some problems in the application of zygomatic implants. CONCLUSION: It is necessary to investigate long-term clinical prognosis.

Adult↗