PURPOSE: Ti-6Al-4V alloy is widely used as an implant material because of its good biocompatibility and good mechanical property compared with commercial pure titanium. Otherwise, toxicity of aluminum and vanadium in vivo has been reported. Ti-8Ta-3Nb alloy is recently developed in the R&D Center for Ti and Special Alloys and it was reported that this alloy has high mechanical strength, no cytotoxicity and similar biocompatibility to commercial pure titanium, but many studies are needed for its clinical use. In these experiment, we carried out different surface treatment on each Ti-8Ta-3Nb alloy disks, then cultured cell on it and assessed biological response. MATERIALS AND METHODS: cpTi, Ti-6Al-4V, Ti-8Ta-3Nb alloy disks were prepared and carried out sandblasting and acid etching (SLA) or alkali-heat treatment (AH) on the Ti-8Ta-3Nb alloy disks. We cultured primary rat calvarial cells on each surface and assessed early cell attachment and proliferation by scanning electron microscopy, cell proliferation, alkaline phosphatase activity. RESULT: The rates of cell proliferation on the cpTi, Ti-8Ta-3Nb AH disks were higher than others (p<0.05) and alkaline phosphatase activity was significantly enhanced on the Ti-8Ta-3Nb AH disks (p<0.05). CONCLUSION: Most favorable cell response was shown on the Ti-8Ta-3Nb AH surfaces. It is supposed that alkali-heat treatment of the Ti-8Ta-3Nb alloy could be induced earlier bone healing and osseointegration than smooth surface.
Alkaline Phosphatase ; Alloys ; Aluminum ; Animals ; Cell Proliferation ; Cells, Cultured ; Microscopy, Electron, Scanning ; Osseointegration ; Rats ; Titanium ; Vanadium

The aim of this study was to evaluate surface characteristics and biological properties of the dentin-derived hydroxyapatite (HA) coating on titanium substrate. Dentin-derived HA was obtained from extracted human teeth using a calcination method at 850degrees C. The commercially pure titanium (cp-Ti, ASTM Grade II) was used as a metallic substrate and a radio frequency magnetron sputtering method was employed as a coating method. Scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) were utilized to investigate the coating aspects and composition. Atomic forced microscopy (AFM) and a surface profiler were used to assess the surface morphology and roughness. Corrosion tests were performed in phosphate-buffered saline at a 36.5 +/- 1degrees C in order to determine the corrosion behavior of the uncoated and coated specimens. The biocompatibility of dentin-derived HA coated specimens with fetal rat calvarial cells and human gingival fibroblasts was assessed by SEM and cell proliferation analysis. The results showed that the dentin-derived HA coatings appeared to cover thinly and homogeneously the surfaces without changing of the titanium substrate. The EDX analysis of this the coating surface indicated the presence of Ca and P elements. The mean surface roughness of cp-Ti and dentin-derived coating specimens was 0.27 microm and, 1.7 microm, respectively. Corrosion tests indicated a stable passive film of the dentin-derived HA coating specimens. SEM observations of fetal rat calvarial cells and human fibroblast cells on coated surfaces showed that the cells proliferated and developed a network of dense interconnections. The cells on all specimens proliferated actively within the culture period, showing good cell viability. At day 1 and 3, dentin-derived coating specimens showed 89% and 93% cell viability, respectively, when normalized to cp-Ti specimens. These results suggest that dentin-derived HA coating using the RF magnetron sputtering method has good surface characteristics and biocompatibility.
Animals ; Cell Proliferation ; Cell Survival ; Corrosion ; Durapatite ; Fibroblasts ; Humans ; Microscopy ; Microscopy, Electron, Scanning ; Rats ; Titanium ; Tooth

PURPOSE: The aim of our study was to assess the hemodynamic change of liver during the Valsalva maneuver using Doppler ultrasonography. METHODS: Thirty healthy men volunteers were enrolled (mean age, 25.5+/-3.64 years). The diameter, minimal and maximal velocities, and volume flow of intrahepatic inferior vena cava (IVC), middle hepatic vein (MHV), and right main portal vein (RMPV) was measured during both rest and Valsalva maneuver. These changes were compared using paired t-test. RESULTS: The mean diameters (cm) of the intrahepatic IVC at rest and Valsalva maneuver were 1.94+/-0.40 versus 0.56+/-0.66 (P<0.001). The mean diameter (cm), minimal velocity (cm/sec), maximal velocity (cm/sec), and volume flow (mL/min) of MHV at rest and Valsalva maneuver were 0.60+/-0.15 versus 0.38+/-0.20 (P<0.001), -7.98+/-5.47 versus 25.74+/-13.13 (P<0.001), 21.34+/-6.89 versus 35.12+/-19.95 (P=0.002), and 106.94+/-97.65 versus 153.90+/-151.80 (P=0.014), respectively. Those of RMPV at rest and Valsalva maneuver were 0.78+/-0.21 versus 0.76+/-0.20 (P=0.485), 20.21+/-8.22 versus 18.73+/-7.43 (P=0.351), 26.79+/-8.85 versus 24.93+/-9.91 (P=0.275), and 391.52+/-265.63 versus 378.43+/-239.36 (P=0.315), respectively. CONCLUSION: The blood flow velocity and volume flow of MHV increased significantly during Valsalva maneuver. These findings suggest that hepatic vein might play an important role to maintain venous return to the heart during the maneuver.
Blood Flow Velocity ; Healthy Volunteers* ; Heart ; Hemodynamics* ; Hepatic Veins ; Humans ; Liver ; Male ; Portal Vein ; Ultrasonography, Doppler* ; Valsalva Maneuver* ; Vena Cava, Inferior ; Volunteers

PURPOSE: Autogenous transplantation of teeth can be defined as transplantation of teeth from one site to another in the same individual, involving transfer of impacted or erupted teeth into extraction sites or surgically prepared sockets". Successful autogenous transplantation of teeth depends upon a complex variety of factors. Such factors include damage to the periodontal ligament of the donor tooth, residual bone height of the recipient site, extra-oral time of tooth during surgery. Schwartz and Andreasen previously reported that autogenous transplantation of teeth with incomplete root formation demonstrated higher success rate than that of teeth with complete root formation. Gault and Mejare yielded similar rate of successful autogenous transplantation both in teeth with complete root formation and in teeth with incomplete root formation when appropriate cases were selected. This case report was aimed at the clinical and radiographic view in autogenous transplantation of teeth with complete root formation. MATERIALS AND METHODS: Patients who presented to the department of periodontics, Chonnam National University Hospital underwent autogenous transplantation of teeth. One patient had vertical root fracture in a upper right second molar and upper left third molar was transplanted. And another patient who needed orthodontic treatment had residual root due to caries on upper right first premolar. Upper right premolar was extracted and lower right second premolar was transplanted. Six months later, orthodontic force was applied. RESULTS: 7 months or 11/2 year later, each patient had clinically shallow pocket depth and normal tooth mobility. Root resorption and bone loss were not observed in radiograph and function was maintained successfully. CONCLUSION: Autogenous transplantation is considered as a predictive procedure when it is performed for the appropriate indication and when maintenance is achieved through regular radiographic taking and follow-up.
Bicuspid ; Follow-Up Studies ; Humans ; Molar ; Molar, Third ; Periodontal Ligament ; Periodontics ; Root Resorption ; Tissue Donors ; Tooth ; Tooth Mobility ; Transplants