The purpose of this study is to evaluate the flow ability of the thermoplasticized Gutta Percha in different temperatures. Four Gutta Percha products were classified by its hardness (soft, medium, and hard) and were experimented by the Rheometer (Melt flow indexer MFI-10, DAVENPORT, England) measuring apparatus, in (23 ± 2) ℃, and in a relative humidity of (50 ± 5) %, following the guidelines of ISO 1133-1:2011. The heating temperature ranged from 108℃, 160℃ to 200℃, and the load at 2.16 kg and 3.8 kg. The Gutta Percha was cut in 5 mm to be suitable for the rheometer pressurization process. After the experiment was conducted with a preheating time of 5 minutes, a cutting time of 5–240 seconds, and a sample of 10 grams, the Gutta Percha did not show any changes in fluidity for 108℃, 160℃, but showed a change in its flow ability in 200℃. Also, the Gutta Percha did not show any changes in its fluidity when it was pressurized by 2.16 and 3.8 kilograms. Therefore, this experiment shows that the heating temperature and the cut-off time showed a significance while measuring the melt flow rate.
Gutta-Percha ; Hardness ; Heating ; Hot Temperature ; Humidity

OBJECTIVES: The purpose of this study is to develop a method of evaluation based on finite element analysis (FEA) using micro-CT images for the measurement of trabecular bone strength. METHODS: The primary compressive trabeculae were obtained from the human femoral head of three cadavers (21 year old male (M/21), 51 year old male (M/51), 51 year old female (F/51). All bone specimens were scanned using micro-CT at 24.9microm of spatial resolution under 70 kV's voltage and current of 141microA. The percent bone volume was calculated from the CTAn (SKYSCAN, Belgium) software, it's represented the bone mineral density (BMD). After scanning, the finite element model was reconstructed based on micro-CT images. All models were applied to be linear elastic, isotropic, and uniform with a tissue modulus of 5.17 GPa and a tissue Poisson's ratio of 0.3. RESULTS: The percent bone volume(%) were 31.819 (+/-0.648), 21.513 (+/-2.489), 20.280 (+/-1.891) and Bone strength (MPa) were 187.741 (+/-13.006), 61.585 (+/-11.094), 61.266 (+/-16.744) in M/20, M/51 and F/51. The trabecular bone strength of the primary compressive trabeculae in M/20 was 3 times more than the trabecular bone strength in M/51 and F/51. The percent bone volume in M/20 was 148% and 157% higher than the percent bone volume in M/51 and F/51. CONCLUSIONS: The finite element analysis is more sensitive than the percent bone volume in reflecting the morphometry index of primary compressive trabeculae. The high resolution FEA reconstructed from high resolution MRI or high resolution CT may improve the evaluation of trabecular bone strength in the medical field.
Bone Density ; Cadaver ; Female ; Finite Element Analysis ; Head ; Humans ; Male

OBJECTIVES: The purpose of this study is to analyze and compare the micro-structural and mechanical properties of subchondral trabecular bone of non-osteoarthritic and osteoarthritic distal femur using micro-images based on finite element analysis. MATERIALS AND METHODS: Twenty distal femurs were harvested from 10 cadavers. The subchondral trabeculae were obtained from the middle of the articular surface of the medial femoral condyle of distal femurs. A total of 20 specimens were scanned using the micro-CT system. Micro-CT images were converted to micro-finite element model using the mesh technique, and micro-finite element analysis was then performed for assessment of the mechanical properties. RESULTS: According to the results, trabecular bone of osteoarthritic distal femur showed a decrease in trabecular thickness, bone volume fraction, structure model index, and yield stress and an increase in trabecular separation and structure model index. CONCLUSIONS: Results of bone morphometry index and strength showed greater deterioration of microstructure and decreased mechanical strength in subchondral trabeculae of the osteoarthritic group.
Cadaver ; Femur ; Humans ; Osteoarthritis

BACKGROUND: The purpose of this study is to investigate differences of chemical composition between subchondral bone in advanced osteoarthritic (OA) and non-OA distal femur. METHODS: Twenty femurs were harvested, respectively. The subchondral trabeculae were obtained from the middle of medial articular surface of distal femurs. A 10 mm diameter cylindrical saw was used to harvest. Raman spectroscopy, a non-destructive technique, was employed to determine the chemical information of the trabecular bones in the human distal femurs. RESULTS: The maximum intensity of the phosphate peak was 2,376.51+/-954.6 for the non-OA group and 1,936.3+/-831.75 for the OA group. The maximum intensity of the phosphate peak observed between the two groups was significantly different (P=0.017). The maximum intensity of the amide I peak were 474.17+/-253.42 for the nonOA group and 261.91+/-205.61 for the OA group. The maximum intensity of the amide I peak were significantly different between the two groups (P=0.042). Also, among other chemical and matrix components (Hydroxyproline,Carbonate, Amide IIIdisordered;ordered, and CH2), the spectrums showed similar significant differences in the intensity (P=0.027, P=0.014, P=0.012; P=0.038, P=0.029). Area integration were performed to determine disorder in collagen's secondary structure via amide III (alpha helix/random coil). The value of the alpha helix to random coil band area are significantly different (P=0.021) and result showing that there was a trend toward higher collagen maturity for the nonosteoarthritic bone specimens. CONCLUSIONS: The result suggested that OA may affect the chemical compositions of trabecular bone, and such distinctive chemical information may be.
Cartilage ; Collagen ; Femur ; Humans ; Osteoarthritis* ; Spectrum Analysis, Raman

PURPOSE: This study aimed to investigate and compare the micro-structural profiles of trabecular bone from different facets at the ankle joint. MATERIALS AND METHODS: In a fresh cadaver ankle, four cored 10 mm of diameter cylindrical specimens of trabecular bone were harvested from the distal tibia, the talar dome, the medial malleolus, and the lateral malleolus. Using a micro-computed tomography, two-dimensional and three-dimensional micro-structural indices of the trabecular bone were analyzed. RESULTS: Each specimen from the tibia, talus, medial malleolus, and the lateral malleolus showed unique micro-structural pattern. Tibia versus talus, the talus was seen a higher bone volume fraction and a wider supporting zone subchondrally whereas the tibia was seen a relatively lower bone volume fraction and a much narrower supporting zone subchondrally. Lateral malleolus versus medial malleolus, the lateral malleolus was seen the thicker but sparse trabeculae pattern whereas the medial malleolus was seen the thinner but more compact trabecular pattern. CONCLUSION: Each four locations from the different facet at the ankle joint have distinct own micro-structural patterns of the trabecular bone, suggesting different mechanical properties.
Ankle Joint* ; Ankle* ; Cadaver ; Talus ; Tibia

BACKGROUND: Human parathyroid hormone(hPTH) is a promising anabolic agent. However, since hPTH (1-34) is available only via injection, and has a critical side effect of causing bone tumors during life-long administration in the rat, it would be practical to use PTH for the shortest possible duration to obtain the maximal effect. In addition, acquired bone mass due to hPTH tend to decrease after drug cessation. To determine the effectiveness of the osteoporosis-reversing concept of lose, restore, and maintain(LRM), recombinant human PTH(1-84)[rhPTH(1-84)] and the respective anti-resorptive agents were sequentially studied. METHODS: Thirty six, 20-week-old, Sprague-Dawley rats were used in this study. Treatment was started on the 25th week after an ovariectomy, which had been performed at 20weeks of age, with 5weeks of rhPTH (1-84) 100(microgram/kg/d), 5days/wk, followed by the respective sequential therapies for 5 weeks as follows: 1) Ovariectomized rats(OVX, n=6), 2) Sham operated rats(SHAM, n=6), 3) OVX rats with PTH maintenance(PTH-M, n=6), 4) OVX rats treated with PTH then withdrawn(PTH-W, n=6), 5) PTH-treated OVX rats then treated with 17beta-estradiol(PTH-E, 10microgram/d, SQ, 5days/wk, n=6), 6) PTH-treated OVX rats then treated with incadronate(PTH-I, 3mg/kg, per os 5 days/wk, n=6). The bone mineral density(BMD) of the right femurs was measured using dual X-ray absorptiometry(DXA). Microcomputed tomography(microCT) was used to measure the structural parameters of the 2nd lumbar vertebrae. A three-point bending test of the femur and compressive tests of vertebrae were also performed. RESULTS: Bone quantity data showed that the femoral BMD was significantly higher in the PTH-M and PTH-I groups than in the OVX and PTH-W groups(P<0.05). Measurement of the cortical thickness revealed that only the PTH-M group had a significant increase(P=0.001). The ultimate force(Fu) at the midshaft of the femur was stronger in the PTH-M group than in the OVX group(P<0.001). However, no significant difference was found among the treated groups. CONCLUSION: PTH withdrawal resulted in the loss of the acquired BMD, but sequential therapy with the anti-resorptive, incadronate, prevented further bone loss. The use of incadronate after rhPTH(1-84), as a sequential regimen, was significantly effective on the maintenance in the bone mass, but further clarification in the improvement in the bone quality is needed.
Animals ; Female ; Femur ; Humans* ; Lumbar Vertebrae ; Osteoporosis ; Ovariectomy ; Rats* ; Rats, Sprague-Dawley ; Spine ; Teriparatide ; X-Ray Microtomography

Two cases of giant cell tumor of bone diagnosed by fine needle aspiration cytology are decribed. Case 1 was a 28-year -old male who had pain sense for one year at the right distal thigh. His radiologic finding revealed a destructive cortical lesion with soft tissue extension at medial side of epiphysis of the distal femur. Case 2 was a 21-year-old female complaining pain at left distal forearm for eight months and showed a well-demarcated expansile osteolytic lesion with multisepatation, and cortical destruction at epiphysis and metaphysis of the left distal radius on the X-ray. Fine needle aspiration of each lesion was performed. The aspirate of the case 1 reveated moderate cellularity, which was composed of scattered giant cells of osteoclastic type and small round to oval monotonous stromal cells in large areas. Giant cells were evenly distributed in single or small groups and had irregular but abundant cytoplasms with 10 to 20 nuclei in the center. The nuclei showed ovoid shape, fine granular chromatin, and a small but conspicuous nucleolus, Stromal cells were dispersed in isolated pattern or sometimes aggregated in clusters and showed the same nuclei as those of giant cells and scanty cytoplasms, Comparing to case 1, case 2 had a more translucent abundant cytoplasm in the giant cells and more spindled stromal cells, All two cases revealed neither nuclear atypism nor increased abnormal mitoses in both giant and stromal cells, suggesting no evidence of malignancy. Therafter the lesions were treated with excision and curettage and histologically confirmed as giant cell tumors of the bone.
Biopsy, Fine-Needle* ; Chromatin ; Curettage ; Cytoplasm ; Epiphyses ; Female ; Femur ; Forearm ; Giant Cell Tumor of Bone ; Giant Cell Tumors* ; Giant Cells* ; Humans ; Male ; Mitosis ; Osteoclasts ; Radius ; Stromal Cells ; Thigh ; Young Adult

Objective: Investigation of new drugs (INDs) is a tremendously inefficient process in terms of time and cost. Drug repositioning is another method used to investigate potential new agents in well-known drugs. This study assessed the survival impact of metformin medication on ovarian cancer. Methods: A national sample cohort of the Korean National Health Insurance Service Data was analyzed. Cox proportional hazards regression was used to analyzing hazard ratios (HRs) and 95% confidence intervals (CIs) after adjusting for underlying diseases and medications as confounding factors for overall survival (OS) and cancer-specific survival (CSS). Results: A total of 866 eligible patients were included from among 1,025,340 cohort participants. Among them, 101 (11.7%) were metformin users. No difference in OS was observed between non-users and users. No difference in OS was observed according to age and Charlson Comorbidity Index. Long-term metformin use (≥720 days) was associated with better OS (adjusted HR=0.244; 95% CI=0.090–0.664; p=0.006). A multivariate Cox proportional hazards model showed that long-term metformin use was an independent favorable prognostic factor for OS (HR=0.193; 95% CI=0.070–0.528; p=0.001) but not for CSS (HR=0.599; 95% CI=0.178–2.017; p=0.408). Conclusion Long-term metformin use reduced all-cause mortality, but not CSS in ovarian cancer. Whether metformin itself reduces deaths because of ovarian cancer requires further investigation.

BACKGROUND: Decay accelerating factor (DAF/CD55), regulates the complement system by accelerating decay of the C3 convertase, has been described in several malignancies, however, the clinicopathologic significance of CD55 and its receptor CD97 has not been fully investigated. We examined the expression patterns of both CD55 and CD97 and their association with clinicopathologic parameters in colorectal cancers (CRCs). METHODS: Expression patterns of CD55 and CD97 in the stroma and tumor cells at tumor center and invasive front were examined in 130 CRCs, and their significance was statistically evaluated. RESULTS: CD55-high stroma was correlated with tumor border (p=0.006) and invasion depth (p=0.013). CD55-high tumor cells at tumor center and invasive front were correlated with histologic grade, and CD55-high tumor cells at invasive front with tumor, node and metastasis (TNM) stage (p<0.05). CD97-high stroma was correlated with lymph node metastasis (p=0.016) and TNM stage (p=0.030). CD97-high tumor cells at tumor center and invasive front were correlated with tumor size and CD97-high tumor cells at tumor center with tumor border (p<0.05). Patients with CD55-high stroma showed poor overall and recurrence-free survival (p<0.05) in univariate analysis, and were independently associated with short recurrence-free survival (p=0.025) in multivariate analysis. CONCLUSIONS: Stromal CD55 overexpression would be an indicator of adverse clinical outcome and a useful prognostic factor.
Antigens, CD55 ; Calcium Hydroxide ; Colorectal Neoplasms ; Complement C3-C5 Convertases ; Complement System Proteins ; Humans ; Immunohistochemistry ; Lymph Nodes ; Neoplasm Metastasis ; Zinc Oxide

BACKGROUND AND OBJECTIVES: Otoacoustic emissions (OAEs) are low level acoustic sounds of cochlear origin. They have several advantages over other methods in auditory testing, particularly in children. However, because of the crucial dependence of emission levels on the healthiness of the middle ear conduction system, some middle ear problems confound the interpretation of evoked OAEs (EOAEs). The purpose of this study is to evaluate the effects of middle ear condition (tympanometry) on DPOAEs and TEOAEs in normal hearers. Materials and Method : Tympanometry, TEOAEs and DPOAEs were measured in 42 subjects (68 ears) who were under 12 years old and have pure tone thresholds within 25 dB HL RESULTS: The OAEs pass rates for the three groups were as follows: 95 % for TEOAEs and 90 % for DPOAEs in the tympanogram type A group; 12 % for TEOAEs and 12 % for DPOAEs in the tympanogram type B group; 27.3 % for TEOAEs and 13.6 % for DPOAEs in the tympanogram type C group. The pass rate and sensitivity of EOAEs were much higher in the type A group than in the type B and C groups. CONCLUSION: OAEs are useful for screening the integrity of outer hair cells in the tympanogram type A group but not in the type B and C groups. Therefore, tympanometry that represents middle ear condition is recommended before the OAE test. In addition, if TEOAEs and DPOAEs are simultaneously performed, sensitivity will be increased.
Acoustic Impedance Tests ; Acoustics ; Child ; Ear, Middle* ; Hair ; Humans ; Mass Screening