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This study examined the effects of graft material on osteoclast-mediated bone remodeling in guided bone regeneration (GBR). Sintered rabbit bone particles were used as the graft material. A polytetrafluoroethylene membrane was molded into a dome and anchored to the frontal bone in 16 male rabbits. The space under the membrane was filled with a blood clot (control group) or sintered bone particles (experimental group). Animals were killed 2, 4, 8, and 12 weeks after operation. The resected samples were fixed in 4% paraformaldehyde and demineralized. Paraffin-embedded histological sections were stained with hematoxylin and eosin and underwent a histochemical assay to determine tartrateresistant acid phosphate (TRAP) activity. The proportions of newly formed bone and graft particles and the numbers and densities of osteoclasts and multinucleated giant cells (MGCs) were calculated. The proportion of newly formed bone increased up to 4 weeks in both the control and experimental groups. Subsequently, the proportion decreased in the control group, but did not change significantly in the experimental group. Osteoclast density on newly formed bone was higher in the control group than that in the experimental group. We conclude that the use of a sintered bone graft inhibits bone resorption by osteoclasts.

Little information has been available on repair of bone defects, whereas numerous studies have been reported on that of bone fractures. The present study was designed to investigate the repairing process of bone defects focusing on the bone healing rate and the cellular activity of extracellular matrix production and degradation using the standardized rat experimental model. Our results indicated that osteoblasts and osteocytes decline bone formation and extracellular matrices (ECM) remodeling resulting in bone healing being ceased within 24 weeks regardless of completion of bone defect repair.

An object of this study was to examine the mold filling capacity of some Ti-Hf alloys. Regardless of the edge angle, the Ti-Hf alloys behaved similar to commercially pure (CP) Ti due to their isomorphous nature of solidifying congruently over the ranges of the alloys examined.

This study electrochemically evaluated corrosion resistance of commercially available cup yoke type magnetic assemblies. Anodic polarization curves in 0.9% NaCl solution at 37°C showed that the magnetic assemblies tested in this study broke down at the range of 0.75–1.3 V because of pitting corrosion in the vicinity of the shield ring of 316L. However, the pitting potentials were significantly higher than that of 316L ( P < 0.05). EPMA showed increase in Cr content on the surface of shield ring compared to its inside ( P < 0.05) because the welding bead deeply covered the surface of shield ring. The laser welding resulted in increasing the pitting potentials of magnetic assemblies.

The Young’s moduli of experimental binary titanium alloys with Cu, Ag, Au, Zr, Nb, or Hf (up to 30 mass%) were determined. As the concentration of Cu increased, the Young’s modulus monotonically increased. As the concentration of Ag, Au, or Nb increased to 20%, the Young’s modulus decreased, followed by a subsequent increase in value. The Young’s modulus monotonically decreased with the increase in the Zr concentration. A slight increase in the Young’s modulus was present when titanium was alloyed with Hf.

This study is an investigation of the bond strength of porcelain to pure titanium, cast and machined by CAD/CAM processes, and a determination of the fracture strength of porcelain fused to pure titanium crown by both methods. The bond strength was evaluated according to the surface treatment conditions. The mean bond strengths were ranged from 36.1 to 49.4 MPa. The surface treatment conditions had a significant effect on the bond strength. The mean fracture strength for the cast frame crowns was 1667 N, and that for the machined frame crowns was 1554 N. There was no significant difference between the two methods. Acceptable bond strength and fracture strength were achieved by both methods.

In this study, TiO_2 films were prepared by Plasma-enhanced Chemical Vapor Deposition (PECVD) using Ti(O- i -Pr)_2(dpm)_2 precursors. The effects of the deposition conditions on the crystalline phases, microstructures, and color of the deposited films were investigated. At a substrate pre-heating temperature T _pre = 623 K, the crystalline phase of the deposited film changed from amorphous to anatase to rutile with increasing microwave power P_M from 0 to 3.0 kW, and the microstructure changed from dense to granular. The deposited film was gray or black but changed to white at a higher T _pre (923 K).

There are a few reports mentioning that we can expand the healing space gradually with the possibility of inducing a new bone. The aim of this study is to determine the possibility to form a new bone by means of using osteogenesis devices in the healing space.

This study investigated the effect of orthopedic force applied by shape memory alloy (SMA) wire on the cranial bone growth in efforts to develop a self-contained orthopedic appliance. Expansive forces and compressive forces were applied by Ni-Ti SMA wires to interparietal sutures in Wistar rats. All rats were killed at day 14 or 28 post-treatment. Morphological analyses by soft X-ray and micro-computed tomography, and histological observation were performed. Cranial width in the expansive groups was increased significantly compared to the control group ( P < 0.01). The increase in cranial width in the compressive groups was inhibited. The results suggest that the self-contained SMA appliance has orthopedic application to the cranium.

The aim of this study was to develop a biosafe and a biocompatible mirror for dental treatment. Mirrors are indispensable manual instruments for dental care and are widely used for intraoral examination and treatment. In this study, light and highly biocompatible mirrors were developed by mirror-polishing of pure titanium and used for dental examination and intraoral photography. The surface roughness and reflectance of the dental mirrors were measured and compared with those of commercially available dental mirrors made of stainless steel. Our results suggested that the pure titanium mirror with a mirror-polished surface was satisfactory for clinical use.