The purpose of this study was to compare the shaping ability of the two different Ni-Ti file systems and the two different engine systems in simulated canals. A total of four groups of each 10 were tested. Each group was instrumented with HeroShaper(R)and Endo-Mate2(R) (Group HE), HeroShaper(R) and Tecnika(R) (Group HT), ProFile(R) and Endo-Mate2(R) (Group PE), and ProFile(R) and Tecnika(R) (Group PT). Canal preparation time was recorded. The images of pre- and post- instrumented root canals were scanned and superimposed. The amounts of increased width and centering ratio were measured and calculated at apical 1, 3 and 5 mm levels. These data were statistically analyzed with one-way ANOVA and Duncan's multiple range test The results of this study were as follows; 1. Canal preparation time of HT group was the shortest (p < 0.05). 2. The amount of increased canal width in HE group was significantly larger than PT group at apical 1 mm level (p < 0.05). At apical 3 mm level, PT group was significantly smaller than other groups (p < 0.05). At apical 5 mm level, PE group was significantly larger than PT group (p < 0.05). 3. The amount of centering ratio in HE group was significantly larger than other groups (p < 0.05). At apical 5 mm level, HT group was significantly larger than PE group and PT group (p < 0.05). Under the condition of this study, torque-controlled endodontic motor is safer than no torque controlled motor, especially when the active file is used.
Dental Pulp Cavity* ; Torque

The purpose of this study was to investigate influence of each file step of ProTaper(R) system on canal transportation. Twenty simulated canals were prepared with either engine-driven ProTaper(R) or manual ProTaper(R). Group R-resin blocks were instrumented with rotary ProTaper(R) and group M-resin blocks were instrumented with manual ProTaper(R). Pre-operative resin blocks and post-operative resin blocks after each file step preparation were scanned. Original canal image and the image after using each file step were superimposed for calculation of centering ratio. The image after using each file step and image after using previous file step were superimposed for calculation of the amount of deviation. Measurements were taken horizontally at five different levels (1, 2, 3, 4 and 5 mm) from the level of apical foramen. In rotary ProTaper(R) instrumentation group, centering ratio and the amount of deviation of each step at all levels were not significantly different (p > 0.05). In manual ProTaper(R) instrumentation group, centering ratio and the amount of deviation of each step at all levels except of 1 mm were not significantly different (p > 0.05). At the level of 1 mm, F2 file step had significantly large centering ratio and the amount of deviation (p < 0.05). Under the condition of this study, F2 file step of manual ProTaper(R) tended to transport the apical part of the canals than that of rotary ProTaper(R).
Dental Pulp Cavity* ; Tooth Apex ; Transportation

The purpose of this study was to analyze the stress distribution aspect of unrestored and restored combined shape (wedge shape occlusally and saucer shape gingivally) class V cavity, which found frequently in clinical cases. A maxillary second premolar restored with a combined shape class V composite restorations were modeled using the three dimensional finite element method. Static occlusal load of 170 N was applied on lingual incline of buccal cusp at the angle of 45degrees with the longitudinal axis of the tooth. And three dimensional finite element analysis was taken by ANSYS (Version 6.0, Swanson Analysis System Co., Houston, U.S.A) program which represent the stress distribution on unrestored and restored cavity wall and margin. The conclusions were as follows. 1. Compared to the unrestored cavity, Von Mises stress at the cementoenamel junction and line angle of the cavity base were reduced and in restored cavity. 2. Von Mises stress at the occlusal and cervical cavity margin and wall were increased in restored cavity in comparison with the unrestored cavity. 3. In the hybrid and hybrid/flowable composite resin restoration, Von Mises stress at the cementoenamel junction and line angle of the cavity base were reduced more than in the flowable restoration. 4. In the hybrid and hybrid/flowable composite resin restoration, Von Mises stress at the occlusal and cervical cavity margin and wall were increased more than in the flowable restoration.
Axis, Cervical Vertebra ; Bicuspid ; Finite Element Analysis ; Tooth ; Tooth Cervix

No abstract available.
Postpartum Period* ; Postpartum Thyroiditis*

Autoimmune postpartum thyroiditis (PPT) has been thought of as one of the organ-specific autoimmune diseases. The present study was designed to investigate whether the immunological changes during the postpartum period might induce this disease, by comparing the circulating lymphocyte subsets and antibody-dependent cell-mediated cytotoxicity (ADCC) between normal postpartum women and PPT patients. The results were as follows: 1) No significant differences in the circulating total T lymphocyte population, or suppressor T lymphocyte subsets, or in Th/Ts ratio were found among 25 PPT patients, 11 normal postpartum women and 11 normal non-pregnant women. 2) In PPT patients, helper T lymphocyte subsets were fewer in proportion than those of normal postpartum or non-pregnant women. However, B lymphocyte population (19.7 +/- 7.8%) and ADCC activity (.41 +/- 13) in PPT patients were comparable to those in normal postpartum women (18.3 +/- 4.8%, .42 +/- .11), although they were significantly greater than those in normal normal non-pregnant women (13.3 +/- 5.9%, .29 +/- .07). In conclusion, the enhancement of immune activities observed in PPT patients was comparable to that in normal postpartum women, suggesting that some other causative or triggering factors might be responsible for the occurrence of this disease.
Adult ; Antibody-Dependent Cell Cytotoxicity ; B-Lymphocytes/immunology ; Female ; Human ; Pregnancy ; Puerperal Disorders/immunology* ; T-Lymphocytes/immunology ; Thyroiditis, Autoimmune/immunology*

Renal transplantation is the optimal treatment for end stage renal disease and it has been improved through the development of operative methods and immunosuppressants. However some patients must receive dialysis or undergo retransplantation after a loss of the primary graft due to rejection or other causes. Recently the frequency of retransplantation has begun to increase gradually. Some articles have reported that retransplantation results do not significantly differ in comparison with initial transplantation results when living related donor kidneys are used. Our study focused on the outcome of 445 first transplantation and 12 retransplantation cases. The sex distribution of retransplanted patients was 11 male and 1 female. The mean age (yrs) for recipients was 32.3 at the first transplantation and 39.1 at the retransplantation. The underlying causes of end stage renal disease were presumed to be chronic glomerulonephritis in all retransplantion patients; the mean duration of graft survival (mo) for first transplantation was 77.92. The causes of previous graft failure were as follows: 10 due to chronic rejection, 1 due to recurrent glomerulonephritis, 1 resulted from a graft rupture due to a motorcar accident. The interval (mo) between graft failure and retransplantation averaged 6.7 and 9 out of 12 patients underwent regrafting within 1 year of their previous graft loss. Recipient-donor relationships in first transplantations were as follows: 9 were living related and 3 were living non-related. Recipient-donor relationships in second transplantations were as follows: 4 were living related and 8 were living non-related. Acute rejection within 1 month of transplantation occurred in 4 primary transplantation patients and 2 retransplantation patients. The incidence of acute rejection within 1 month was as follows: 23% of 445 first renal transplantation patients, 16.7% of 12 second transplantation patients. The 1 year and 2 year graft survival rate was 100% and the mean survival duration (mo) was 33 for retransp
Dialysis ; Female ; Glomerulonephritis ; Graft Survival ; Humans ; Immunosuppressive Agents ; Incidence ; Kidney Failure, Chronic ; Kidney Transplantation ; Kidney* ; Male ; Rupture ; Sex Distribution ; Tissue Donors ; Transplants