The use of pure titanium and titanium alloys have been increased recently in fixed, removable prosthodontics and implant fields as a framework. But when they were used for superstructures of implant of metal framework of removable prosthesis, welding is necessary to reconnect the fracture site to control the casting distortions. To overcome the difficulties in soldering the titanium due to high oxidation property, much effort have been devoted. In this study, some of mechanical properties were compared between pure titanium and Ti-6Al-4V alloy by usingl aser welding, electron beam welding technique and tungsten arc welding. Mechanical properties such as tensile strength, yield strength, elongation and microhardness were measured. And, in order to compare the effect of welding site and surrounding metal tissue according to the welding condition, SEM photographs were taken an element distribution was observed by Wave Dispersion Spectroscopy. Through analyses of the data, following results were obtained; 1. In items such as tensile strength, yield strength and elongation according to the welding techniques of pure titanium, only tungsten arc welded group showed significant lower value than other groups(P<0.05). 2. In items such as tensile strength and yield strength according to the welding techniques of Ti-6Al-4V alloy, control group and tungsten arc welded group showed significant difference among all the groups(P<0.05). 3. Ti-6Al-4V alloy exhibited significantly greater elongation than control group when the laser welding method and electron beam welding method were used, and elongation showed increasing tendency. 4. Pure titanium specimens exhibited increasing tendency of microhardness regardless of the welding technique applied, and especially tungsten arc welded group demonstrated a great increase of microhardness than parent metal. 5. There was no hardness change in laser welded group and electron bean welded group of Ti-6Al-4V ally, but in tungsten arc welded group, hardness changed greatly from parent metal to weld seam. 6. Through the metallographic examination and scanning electron microscopy, laser welding caused central fusion and recristallizations were formed and tungsten arc welding caused localized fusion to 0.3-0.7mm from the surface.
Alloys ; Hardness ; Humans ; Microscopy, Electron, Scanning ; Parents ; Prostheses and Implants ; Prosthodontics ; Spectrum Analysis ; Tensile Strength ; Titanium* ; Tungsten ; Welding*

No abstract available.
Female* ; Humans ; Prune Belly Syndrome*

PURPOSE: The aim of this study was to investigate a comparison of implant bone bed preparation with Er,Cr:YSGG laser and conventional drills on the relationship between implant stability quotient (ISQ) values and implant insertion variables. MATERIALS AND METHODS: Forty implants were inserted into two different types of pig rib bone. One group was prepared with conventional drills and a total of 20 implants were inserted into type I and type II bone. The other group was prepared with a Er,Cr:YSGG laser and a total of 20 implants were inserted into type I and type II bone. ISQ, maximum insertion torque, angular momentum, and insertion torque energy values were measured. RESULTS: The mean values for variables were significantly higher in type I bone than in type II bone (P < .01). In type I bone, the ISQ values in the drill group were significantly higher than in the laser group (P < .05). In type II bone, the ISQ values in the laser group were significantly higher than in the drill group (P < .01). In both type I and type II bone, the maximum insertion torque, total energy, and total angular momentum values between the drill and laser groups did not differ significantly (P > or = .05). The ISQ values were correlated with maximum insertion torque (P < .01, r = .731), total energy (P < .01, r = .696), and angular momentum (P < .01, r = .696). CONCLUSION: Within the limitations of this study, the effects of bone bed preparation with Er,Cr:YSGG laser on the relationship between implant stability quotient (ISQ) values and implant insertion variables were comparable to those of drilling.
Mandrillus ; Ribs ; Salicylates ; Torque

OBJECTIVE: To test if the intake of H2 receptor antagonists (H2-RAs) increases the risk of gastric cancer in the elderly. METHODS: The source population for this study was drawn from the responders to a questionnaire survey administered to the Korea Elderly Pharmacoepidemiological Cohort (KEPEC), who were beneficiaries of the Korean Medical Insurance Corporation, were at least 65 years old, and residing in Busan in 1993. The information on H2-RAs exposure was obtained from a drug prescription database compiled between Jan. 1993 and Dec. 1994. The cases consisted of 76 gastric cancer patients, as confirmed from the KMIC claims data, the National Cancer Registry and the Busan Cancer Registry. The follow-up period was from Jan. 1993 to Dec. 1998. Cancer free controls were randomly selected by 1:4 individual matching, which took in to consideration the year of birth and gender. Information on confounders was collected by a mail questionnaire survey. The odds ratios, and their 95% confidence intervals, were calculated using a conditional logistic regression model. RESULTS: After adjusting for a history of gastric ulcer symptoms, medication history, and body mass index, the adjusted OR (aOR) was 4.6 (95% CI=1.72-12.49). The odds ratio of long term use (more than 7 days) was 2.3 (95% CI=1.07-4.82). The odds ratio of short term use was 4.6 (95% CI=1.26-16.50). The odds ratio of parenteral use was 4.4 (95% CI=1.16-17.05) and combination use between the oral and parenteral routes (aOR, 16.8; 95% CI=1.21-233.24) had the high risk of gastric cancer. The aOR of cimetidine was 1.7 (95% CI=1.04-2.95). The aOR of ranitidine was 2.0 (95% CI=1.21-3.40). The aOR of famotidine was 1.7 (95% CI=0.98-2.80). CONCLUSION: The intake of H2-RAs might increase the risk of gastric cancer through achlorhydria in the elderly.
Achlorhydria ; Aged* ; Body Mass Index ; Busan ; Case-Control Studies* ; Cimetidine ; Cohort Studies ; Drug Prescriptions ; Famotidine ; Follow-Up Studies ; Humans ; Insurance ; Korea ; Logistic Models ; Odds Ratio ; Parturition ; Pharmacoepidemiology ; Postal Service ; Surveys and Questionnaires ; Ranitidine ; Stomach Neoplasms* ; Stomach Ulcer

To elucidate the effects of food texture such as hardness, cohesiveness, adhesiveness on mastication procedure, the electromyographic activity (EMG) of the masticatory muscles and the chewing movements were analyzed in eighteen young subjects during ordinary chewing. Seven different foods were selected by sensory texture profiling and mechanical test with texturometer; egg white, sausage, pizza cheese, yang-geng, biscuit, peanut and almond. The indexes of jaw movements used were the chewing number, chewing time, maximum opening, average opening, closing velocity and opening velocity. The EMG indexes analyzed were maximum and average integrated amplitude of the anterior temporal and masseter muscles. The results obtained were as follows. 1. The chewing time and chewing number, mandibular displacement and mandibular movement velocity were not changed by the hardness, cohesiveness and adhesiveness of the food (p>0.05). 2. The harder food materials showed a higher amplitude of the anterior temporal muscle integrated EMGs than the softer ones (p<0.05). 3. The maximum and average integrated EMGs of the masseter muscle increased with the increase of hardness of the food (p<0.05). 4. The integrated EMGs of preferred side and non-preferred side masticatory muscles increased with the increase of hardness of the food (p<0.05). 5. The adhesiveness and cohesiveness of the food were not the determining factor to the integrated EMGs of masticatory muscles (p<0.05).
Adhesiveness ; Cheese ; Egg White ; Hardness ; Jaw ; Masseter Muscle ; Mastication* ; Masticatory Muscles* ; Prunus dulcis ; Temporal Muscle

The diffuse large B-cell lymphoma category of the Revised European American Classification of Lymphoid Neoplasms (REAL) encompasses different morphologic lymphoma subtypes in a single entity, especially the diffuse large cell (DLC) and the immunoblastic (IBL) subtypes by Working Formulation (WF). The aim of this study is to determine the influence of the morphologic subdivision within this category with respect to clinical outcome and proliferative index using Ki-67 immunostainig combined with image analysis. We retrospectively reviewed 74 patients from 1990 to 1996, who were diagnosed with diffuse large B-cell lymphoma. All cases were reclassified according to REAL and Working Formulation (WF), and Ki-67 immunostaining was performed in all the cases. Fifty-eight cases (78.4%) were classified as DLC and 16 cases (21.6%) as IBL, according to WF. Twenty one cases (28.4%) showed nodal involvement and 53 cases (71.6%), extranodal involvement. All cases were found to display a variable degree of nuclear Ki-67 staining. A proliferative index of 50% or higher identified a group of patients (77%) who had poor clinical results. Overall survival was significantly reduced in these patients displaying high Ki-67 associated proliferative index compared to those with a low proliferative index (p=0.007). 5-year survival estimates were 93% in the low proliferative index group and 55% in the high proliferative index group. A multivariate regression analysis incorporating commonly used clinical prognostic factors confirmed the independent effect of proliferation index on survival. Moreover, all of the 16 IBL cases showed Ki-67 positivity of 50% or higher, which correlates with the poor clinical outcome compared to 70.7% of DLC (p=0.014). We conclude that subdivision of the diffuse large B-cell lymphoma category of the REAL classification is necessary in terms of prognostic significance in correlation with Ki-67 proliferative index.
B-Lymphocytes* ; Classification ; Humans ; Lymphoma ; Lymphoma, B-Cell* ; Lymphoma, Large B-Cell, Diffuse ; Retrospective Studies

PURPOSE: The aim of this article is to analyze the preference for treatment modality of dentists. MATERIAL AND METHODS: Data of 20,038 patients was involved. Data analysis were done by distribution according to the various kinds of prosthesis, including complete denture, removable partial denture, fixed partial denture, implant-supported dental prosthesis as well as distribution according to the professional titles of the dentists finishing the treatment, including resident and professors. RESULTS: The number of cases of dental prosthesis increased year by year. 61.06% of the patients accepted fixed partial denture restoration. The number of patients who accepted implant supported restoration is also increasing year by year. The number of complete denture, implant-supported dental prosthesis finished by professors was larger than that done by residents, while it was contrary for removable partial denture, fixed partial denture, and the difference was statistically significant (P<.05). CONCLUSION: Professors and residents have some difference in the categorization of prosthesis finished. Fixed partial denture and implant-supported dental prosthesis are preferred.
Dental Prosthesis ; Dental Prosthesis, Implant-Supported ; Dentists ; Denture, Complete ; Denture, Partial, Fixed ; Denture, Partial, Removable ; Humans ; Prostheses and Implants ; Prosthodontics ; Statistics as Topic

BACKGROUND: Homelessness is associated with an increased risk of exposure to Mycobacterium tuberculosis. Several factors, including alcoholism, malnutrition, lack of stable housing, combine to make tuberculosis more prevalent in the homeless. The aims of this study were to determine the factors associated with increasing success rate of tuberculosis treatment in the homeless. METHODS: A cross-sectional analysis of the clinical features in 142 pulmonary tuberculosis-positive homeless patients admitted to the Busan Medical Center from January 2001 to December 2010 was carried out. These results were compared with a successful treatment group and incomplete treatment group. We also evaluated the risk factors of treatment non-completion. Statistical analysis for the comparisons was performed using a chi2 test, independent samples t-test, and multiple logistic regression. RESULTS: Comparison of clinical characteristics showed significant differences between the two groups in the type of residence (P < 0.001), diseases with risk factors (P = 0.003), and history of tuberculosis treatment (P = 0.009). Multiple regression analysis revealed the residence (odds ratio [OR], 4.77; 95% confidence interval [CI], 2.05 to 11.10; P < 0.001) and comorbidity with risk factor (OR, 2.72; 95% CI, 1.13 to 6.53; P = 0.025) to be independently associated with treatment success. CONCLUSION: To improve the success rate of tuberculosis treatment in the homeless person, anti tuberculosis medication should be taken until the end of treatment and a management system for the homeless person is required. Further social and medical concerns for stable housing and management of comorbidity may lead to an improvement in the successful tuberculosis treatment of homeless person.
Alcoholism ; Comorbidity ; Cross-Sectional Studies ; Homeless Persons ; Hospitals, Public ; Housing ; Humans ; Malnutrition ; Mycobacterium tuberculosis ; Risk Factors ; Tuberculosis ; Tuberculosis, Pulmonary

The goal of the present study was to evaluate the diagnostic value of a joint distractor in arthroscopy in small-breed dogs. Sixty stifle joints, which were collected from thirty cadavers, were used in this study. To simulate different injuries, no medial meniscal tear, a full-thickness vertical longitudinal tear, a partial-thickness vertical longitudinal tear, full- and partial-thickness vertical longitudinal tears, or a peripheral detachment were created on the caudal horn of the medial meniscus of each stifle joint along with rupture of the cranial cruciate ligament. Each stifle joint then underwent arthroscopy with and without a joint distractor. The sensitivity (Sn), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), and correct classification rate (CCR) for the diagnosis of each type of medial meniscus pathology were calculated. For arthroscopy with and without a joint distractor, the Sn was 85% and 60%, the Sp was 96% and 92%, the PPV was 85% and 65%, the NPV was 96% and 90%, and the CCR was 94% and 86%, respectively. Arthroscopy is an effective diagnostic method for the assessment of medial meniscal pathologies in small-breed dogs, especially when performed with the aid of a joint distractor.
Animals ; Anterior Cruciate Ligament ; Arthroscopy ; Cadaver ; Classification ; Diagnosis ; Dogs* ; Horns ; Joints* ; Menisci, Tibial ; Methods ; Pathology ; Rupture ; Sensitivity and Specificity ; Stifle ; Tears

PURPOSE: Most of studies dealing with abfractions are limited to the buccal surfaces of the teeth. In this study, we analyzed the cause for abfraction by investigating the incidence of palatal side abfractions in maxillary posterior teeth. MATERIALS AND METHODS: We investigated a total of 3193 maxillary posterior teeth by an intraoral examination, model observation, and observation of virtual model fabricated using model scanning. We recorded the results and classified them depending on the type of teeth, age, gender, and side of arches. We also performed Chi-square test to evaluate the statistical significance among the groups (α = 0.05). RESULTS: The incidence of palatal side abfraction of the maxillary molars (10.8%) was higher than the premolars (6.8%), and among them, the incidence of the 1st molars (39.1%) were the highest. The incidence of palatal side abfraction increased with age and was statistically significant (P < 0.05). There was no statistical significance in the difference by gender (P > 0.05); in the case of arches, left arch showed higher incidence and it was statistically significant (P < 0.05). CONCLUSION Palatal side abfraction in maxillary posterior teeth was frequently observed in the maxillary 1st molars, and the incidence increased with age. This result suggests that the main reason for abfraction is due to occlusal force.