title: Appositional bone formation by OCP-collagen composite.
abstract: Synthetic octacalcium phosphate (OCP) has been shown to enhance bone formation and to biodegrade if implanted into bone defects. Here, we hypothesized that an OCP-atelocollagen complex (OCP/Col) is biodegradable and can induce bone formation in a thickness-dependent manner when implanted into the calvaria. OCP/Col disks (diameter, 9 mm; thickness, 1 or 3 mm) were implanted into a subperiosteal pocket in the calvaria of 12-week-old Wistar rats for 4, 8, and 12 weeks and subsequent bone formation was monitored. X-ray diffraction analysis and Fourier transform infrared spectroscopy showed that OCP in the OCP/Col implants was converted into a carbonate-rich apatite after 4 weeks. Although thinner disks tended to be replaced by new bone, thicker disks were progressively resorbed by osteoclast-like cells until 12 weeks, possibly via the increased mechanical load in the subperiosteal pocket. Therefore, OCP/Col can increase appositional intra-membranous bone formation if the appropriate size of the implant is applied.
authors.affiliation: Division of Advanced Prosthetic Dentistry, Tohoku University Graduate School of Dentistry, 4-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Suzuki
authors.forename: S
authors.initials: S
authors.lastname: Kamakura
authors.forename: Y
authors.initials: Y
authors.lastname: Honda
authors.forename: T
authors.initials: T
authors.lastname: Anada
authors.forename: K
authors.initials: K
authors.lastname: Hatori
authors.forename: K
authors.initials: K
authors.lastname: Sasaki
authors.forename: O
authors.initials: O
authors.lastname: Suzuki
mesh_terms: D020341:Absorbable Implants; D000135:Acid Phosphatase / Q000032:analysis; D000818:Animals; D001031:Apatites / Q000737:chemistry; D015415:Biomarkers / Q000032:analysis; D018786:Bone Substitutes / Q000737:chemistry / Q000627:therapeutic use*; D002130:Calcium Phosphates / Q000737:chemistry / Q000627:therapeutic use*; D056657:Cathepsin K / Q000032:analysis; D003094:Collagen / Q000737:chemistry / Q000627:therapeutic use*; D004337:Drug Carriers; D007527:Isoenzymes / Q000032:analysis; D008297:Male; D010010:Osteoclasts / Q000473:pathology; D010012:Osteogenesis / Q000502:physiology*; D010521:Periosteum / Q000473:pathology / Q000601:surgery; D011474:Prosthesis Design; D051381:Rats; D017208:Rats, Wistar; D012886:Skull / Q000473:pathology / Q000601:surgery; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical; D000071681:Tartrate-Resistant Acid Phosphatase; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D001031:Apatites; D015415:Biomarkers; D018786:Bone Substitutes; D002130:Calcium Phosphates; D004337:Drug Carriers; D007527:Isoenzymes; C059821:atelocollagen; C022045:octacalcium phosphate; C030782:carboapatite; D003094:Collagen; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; D056657:Cathepsin K