title: Mechanical stress-related calvaria bone augmentation by onlayed octacalcium phosphate-collagen implant.
abstract: Previous studies have suggested that the biodegradability of octacalcium phosphate-collagen (OCP/Col) composite by osteoclasts is accelerated in association with mechanical stress suffered by the host tissue around the implant. The present study was designed to investigate whether alleviation of mechanical stress restores the bone regenerative properties of OCP/Col, as previously shown in nonload-bearing sites. OCP/Col discs supported with a polytetrafluoroethylene (PTFE) ring, which has a higher modulus than OCP/Col, were implanted in a rat subperiosteal pocket for up to 12 weeks. The structural features of the implant and biological responses were analyzed by X-ray diffraction, Fourier transform infrared spectroscopy, histomorphometry, histochemistry, and tissue mRNA expression around the implants. The effect of compression was analyzed using mouse stromal ST-2 cells by deforming the cell-seeded OCP/Col discs in vitro with or without a PTFE ring. The results clearly indicated the restoration of bone formation by the alleviation of mechanical stress and the upregulation of osteoblast-related genes, such as osterix on the other hand, the implantation of OCP/Col on calvaria or in an in vitro test without PTFE support resulted in the upregulation of osteoclast-related genes, such as tartrate-resistant acid phosphatase (TRAP) and cathepsin K, in the tissues or receptor activator of the nuclear factor-kappaB ligand (RANKL) in ST-2 cells. The results confirmed that calvaria augmentation is enhanced by implanting OCP/Col if suitable conditions regarding mechanical stress are provided.
authors: Division of Oral Surgery, Tohoku University Graduate of Dentistry, Sendai, Japan.
authors: Aritsune
authors: A
authors: Matsui
authors: Takahisa
authors: T
authors: Anada
authors: Taisuke
authors: T
authors: Masuda
authors: Yoshitomo
authors: Y
authors: Honda
authors: Naohisa
authors: N
authors: Miyatake
authors: Tadashi
authors: T
authors: Kawai
authors: Shinji
authors: S
authors: Kamakura
authors: Seishi
authors: S
authors: Echigo
authors: Osamu
authors: O
authors: Suzuki
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology* / Q000378:metabolism; D002130:Calcium Phosphates; D056657:Cathepsin K / Q000096:biosynthesis; D002460:Cell Line; D003094:Collagen; D008297:Male; D051379:Mice; D053245:RANK Ligand / Q000096:biosynthesis; D051381:Rats; D012886:Skull / Q000166:cytology* / Q000378:metabolism; D012887:Skull Fractures / Q000378:metabolism / Q000628:therapy; D013312:Stress, Physiological; D017154:Stromal Cells / Q000166:cytology / Q000378:metabolism
chemical_list: D002130:Calcium Phosphates; D053245:RANK Ligand; C505689:Tnfsf11 protein, mouse; C022045:octacalcium phosphate; D003094:Collagen; D056657:Cathepsin K; C534132:Ctsk protein, mouse