tetracycline and xylenol-orange

The purpose of the present study was to evaluate histologically in beagle dogs the healing in acute dehiscence type defects following treatment with open flap debridement (OFD) with or without porous biphasic calcium phosphate (PBCP). Alveolar bone dehiscence defects were surgically created bilaterally at the labial aspects of maxillary third incisors in 12 beagle dogs. After root conditioning with ethylenediaminetetraacetate, PBCP was filled in the defects and the contralaterals were cured with OFD. Two fluorochrome labelings were administered at the 7th and 11th weeks, respectively. Four dogs were killed at the 12, 16, and 24 weeks, respectively. Histological observations were processed through microcomputed tomographic imaging, fluorescence microscope, and light microscopy. The formation of new regenerated tissues was assessed histomorphometrically. The results revealed the healing after treatments with PBCP evidenced a new attachment apparatus and that with OFD supported periodontal repair. In PBCP groups, the amount of new bone varied from 1.15 to 3.86 mm (23-77.2% of the original defect size), while only 0.3 to 1.04 mm (6-20.8%) in OFD group. The amount of new cementum in PBCP varied from 1.18 to 4.16 mm (23.6-82.3%), while only 0.67 to 1.15 mm (13.4-23%) in OFD group. The amount of periodontal ligament in PBCP varied from 1.03 to 4.12 mm (20.6-82.4%), while only 0 to 0.93 mm (0-18.6%) in OFD group. There was significantly more regenerated tissue in PBCP groups compared to OFD procedures (p < 0.01). The present results indicate that PBCP may enhance periodontal regeneration in acute-type labial dehiscence defects.

Topics: Alveolar Bone Loss; Alveolar Process; Animals; Bone Regeneration; Bone Substitutes; Ceramics; Chelating Agents; Debridement; Dental Cementum; Dogs; Edetic Acid; Fluorescent Dyes; Hydroxyapatites; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; Incisor; Male; Microscopy, Fluorescence; Periodontal Ligament; Phenols; Regeneration; Sulfoxides; Surgical Flaps; Tetracycline; Time Factors; Tooth Root; Wound Healing; X-Ray Microtomography; Xylenes

The aim of this study was to compare angiogenesis and osteogenesis occurring within 8.0 mm diaphyseal defects created in canine tibiae treated using autograft or a biodegradable bone scaffold. All tibiae were reamed to 7.0 mm and fixed with a 6.5-mm statically locked intramedullary nail. Each of the 18 canines as allotted to one of three treatment groups: (1) left empty (N = 5), (2) treated with iliac crest autograft (N = 6), or (3) treated with a PLGA/calcium phosphate biodegradable scaffold (N = 7). Fluorescent markers were given at successive time periods: calcein green at 6 weeks, xylenol orange at 9 weeks, and tetracycline at 11 and 14 weeks. Animals were sacrificed at 15 weeks and their legs were perfused with a radio opaque compound. Samples were analyzed using Micro CT, bright-field microscopy and fluorescent microscopy. Scaffold samples were found to have significantly greater bone formation (p = 0.015) and blood vessel formation (p < 0.001) at their osteotomy sites than autograft samples. Bone formation rate in the periosteum was significantly greater in the autograft samples than the scaffold samples for all time periods. Bone formation at the osteotomy site was found to be significantly greater when associated with greater blood vessel formation (p = 0.026). The PLGA/calcium phosphate biodegradable scaffold we have employed supports angiogenesis within a segmental tibial defect that has adequate soft tissue coverage.

Topics: Absorbable Implants; Animals; Bone Substitutes; Bone Transplantation; Calcium Phosphates; Disease Models, Animal; Dogs; Fluoresceins; Fluorescent Dyes; Fracture Fixation, Intramedullary; Fracture Healing; Ilium; Lactic Acid; Neovascularization, Physiologic; Osteogenesis; Osteotomy; Phenols; Polyglycolic Acid; Polylactic Acid-Polyglycolic Acid Copolymer; Radiography; Sulfoxides; Tetracycline; Tibial Fractures; Time Factors; Tissue Scaffolds; Transplantation, Homologous; Xylenes

Distribution of bone remodeling units (BRU) in relation to the perilymphatic space was studied in undecalcified temporal bones from adult rabbits labeled in vivo with bone-seeking fluorochromes. Based on recordings of focal bone formation, relative densities of BRUs inside concentric tissue zones around the inner ear spaces were estimated. Zonal densities of BRUs were found to decline towards the perilymphatic space, lending further support to the existence of a local inner ear mechanism in control of capsular bone tissue dynamics. The possible nature of this mechanism is considered briefly with special reference to inner ear electromechanic activity.

Topics: Animals; Anthraquinones; Bone Density; Bone Remodeling; Demeclocycline; Ear, Inner; Fluoresceins; Haversian System; Microscopy, Fluorescence; Oxytetracycline; Phenols; Rabbits; Sulfoxides; Temporal Bone; Tetracycline; Xylenes

The early (3 months) and later (6 months) patterns of incorporation and bone formation have been evaluated histomorphometrically for different types of bone grafts; that is, vascularized and nonvascularized autografts with and without ciclosporin, and vascularized and nonvascularized dog leukocyte antigen (DLA)-mismatched allografts with and without ciclosporin. The vascularized bones were superior to the nonvascularized ones in healing and remodeling their grafted segments. In the autograft bones, ciclosporin did not alter the incorporation process 3 months after transplantation but delayed and increased the remodeling activities in the long run (6 months). Nonvascularized allografts underwent vigorous resorption, and were markedly porotic. Ciclosporin administration significantly reduced resorption and enhanced remodeling in nonvascularized allografts. The remodeling of allografts was similar to that of autografts in the presence of ciclosporin, but stopped soon after the administration of ciclosporin ceased.

Topics: Animals; Bone Regeneration; Bone Resorption; Bone Transplantation; Cyclosporins; Dogs; Fibula; Fluorescent Dyes; Histocompatibility Testing; Periosteum; Phenols; Premedication; Sulfoxides; Tetracycline; Transplantation, Autologous; Transplantation, Homologous; Xylenes