ABSTRACTS (BY NUMBER)

Abstract

Octacalcium phosphate and collagen composite (OCPcol) demonstrated superior bone regeneration with angiogenesis (1, 2), and have been commercialized recently in Japan (3). Teriparatide (TPTD) is a bioactive recombinant form of parathyroid hormone that is approved for osteoporosis treatment. And OCPcol with a local single administration of TPTD enhanced bone repair of a rodent critical-sized bone defect (4, 5). Because mandibular bone reconstruction after segmental resection is a key clinical problem, it was examined whether single-dose local administration of OCPcol with TPTD can affect recovery after this procedure. OCPcol was prepared, and a commercially available hydroxyapatite and collagen composite (HAPcol) was used as a control. A 15 mm length segmental bone defect was made in the mandibular region of male beagle dogs. The experimental animals were divided in four groups. OCPcol treated with TPTD (OCPcol+TPTD), OCPcol, HAPcol treated with TPTD (HAPcol+TPTD), or HAPcol was implanted into the defect. The radiopaque areas of the implanted site were measured and statistically analyzed, and histological examination was performed after 6 months. The value of radiopaque area in total region of OCPcol+TPTD was highest, followed in order by OCPcol, HAPcol+TPTD, and HAPcol, and that of OCPcol+TPTD was significantly higher than that of HAPcol+TPTD or HAPcol. All segmented mandibles of OCPcol+TPTD and a part of those of OCPcol were bridged with newly formed bone, whereas no bone bridges were observed in HAPcol+TPTD or HAPcol. These results suggested that OCPcol treated with TPTD enabled bone reconstruction after segmental mandibular resection more than other three groups.