Wound healing/regeneration using recombinant human growth/differentiation factor-5 in an injectable poly-lactide-co-glycolide-acid composite carrier and a one-wall intra-bony defect model in dogs.

OBJECTIVE: The purpose of this study was to evaluate the effect of recombinant human growth/differentiation factor-5 (rhGDF-5) on periodontal wound healing/regeneration using an injectable poly-lactide-co-glycolide-acid (PLGA) composite carrier and an established defect model. METHODS: Bilateral 4 × 5 mm (width × depth) one-wall, critical-size, intra-bony periodontal defects were surgically created at the second and the fourth mandibular pre-molar teeth in 15 Beagle dogs. The animals were randomized to receive (using a split-mouth design; defect sites in the same jaw quadrant getting the same treatment) rhGDF-5 high dose (188 µg/defect) versus sham-surgery control (five animals), rhGDF-5 mid dose (37 µg/defect) versus carrier control (five animals), and rhGDF-5 low dose (1.8 µg/defect) versus treatment reported elsewhere (five animals). The animals were euthanized for histometric analysis following an 8-week healing interval. RESULTS: Clinical healing was uneventful. The rhGDF-5/PLGA construct was easy to assemble and apply. The rhGDF-5 high dose supported significantly increased bone formation compared with the low-dose, sham-surgery, and carrier controls (p<0.05) and induced significantly increased cementum formation compared with the controls (p<0.05). Root resorption/ankylosis or other aberrant healing events were not observed. CONCLUSION: rhGDF-5 appears to effectively support periodontal wound healing/regeneration in a dose-dependent order; the PLGA composite appears to be an effective ease-of-use candidate for carrier technology.

Effects of calcium phosphate coating to SLA surface implants by the ion-beam-assisted deposition method on self-contained coronal defect healing in dogs.

The aim of this study was to evaluate the healing of self-contained coronal defects on a sand-blasted, large-grit, acid-etched (SLA) surface implant, which had a calcium phosphate (CaP) coating applied by ion-beam-assisted deposition (IBAD). We also evaluated the effect of heating the coating to different temperatures. The CaP-coated SLA implants exhibited a slightly larger bone healing capacity in the self-contained coronal defect than SLA implants, indicating that combining SLA surface implants and a CaP coating by the IBAD method had synergistic effects on bone healing. There was no difference in the healing capacity between 350 degrees C and 450 degrees C heat treatment of the coating layer.

The effects of hydroxyapatite/calcium phosphate glass scaffold and its surface modification with bovine serum albumin on 1-wall intrabony defects of beagle dogs: a preliminary study.

The purpose of this study was to evaluate the effects of biphasic hydroxyapatite/calcium phosphate glass (HA/CPG) scaffold and its surface modification with bovine serum albumin (BSA) on periodontal regeneration. 1-wall intrabony defects were surgically created on five beagle dogs. HA/CPG scaffolds, with a hydroxyapatite (HA)/calcium phosphate glass (CPG) ratio of 95:5 by weight (%) and surface modification done by 2% bovine serum albumin, were used. The control group received surgical flap operation, and the experimental groups were filled with HA/CPG scaffolds and HA/CPG(BSA) scaffolds. The animals were sacrificed eight weeks after surgery. Histological findings revealed better space maintenance in the experimental groups than the control group, and showed new bone formation intermittently in between the residual material particles. The newly formed bone was mostly woven bone and the residual particles were undergoing resorption. Cementum regeneration was observed with limited root resorption in all the groups. Histometric analysis also revealed greater mean values in new bone formation, cementum regeneration and bone area than the control group in both experimental groups. However, similar findings were presented between HA/CPG and HA/CPG(BSA). The result of the present study revealed the newly fabricated HA/CPG scaffold to have a potential use as a bone substitute material.