1.CT Appearance of Internal Hernia:Whorling Sign of Mesentery and Mesenteric Vessels.
Tae Hun KIM ; Won Ho KIM ; Geun Seok YANG ; Sung Woo KIM ; Duk Sik KANG
Journal of the Korean Radiological Society 1995;32(2):297-302
PURPOSE: To evaluate CT findings of internal hernia. MATERIALS AND METHODS: Three patients with internal hernia had abdominal CT scans and two of them had small bowel follow through examinations. The CT features of two patients with retroanastomotic and one patient with left paraduodenal hernia were evaluated and correlated with small bowel follow through examinations, and surgical findings. Two patients with retroanastomotic hernia had a history of subtotal gastrectomy with antecolic gastrojejunostomy. The diagnosis of internal hernia was made on the basis of surgical find ings in two patients of retroanastomotic hernia, and characteristic barium study findings in one patient of left paraduodenal hernia. RESULTS: The small bowel follow through examination showed small bowel loops gathered in a circumscribed mass in the left mid abdomen, and delay in passage through these loops. In case of left paraduodenal hernia, abrupt narrowing of the distal duodenum could be identified. The characteristic CT findings of all three patients were whorling of the mesentery and mesenteric vessels in the left mid-abdomen. In the patient with left paraduodenal hernia, after resolution of the gastrointestinal symptoms, a follow-up CT scan showed spontaneous disappearance of whorling of the mesentery and mesenteric vessels suggesting spontaneous resolution of the hernia. In the other two cases, upon exploration of the abdomen, dilatation of afferent duodenum caused by adhesion between ligament of Treitz and adjacent bowel walls, and retro- anastomotic herniation of the efferent loops were found. CONCLUSION: The usual diagnosis of internal hernia is based on the appearance of the small bowel follow through examination. However, we consider that the whorling appearance(we call it whorling sign) of the mesentery and mesenteric vessels on CT scan is also suggestive of internal hernia in patients under clinical suspicion.
Abdomen
;
Barium
;
Diagnosis
;
Dilatation
;
Duodenum
;
Follow-Up Studies
;
Gastrectomy
;
Gastric Bypass
;
Hernia
;
Humans
;
Ligaments
;
Mesentery*
;
Tomography, X-Ray Computed
2.Influence of porcelain veneering on the marginal fit of Digident and Lava CAD/CAM zirconia ceramic crowns.
Hyun Soon PAK ; Jung Suk HAN ; Jai Bong LEE ; Sung Hun KIM ; Jae Ho YANG
The Journal of Advanced Prosthodontics 2010;2(2):33-38
PURPOSE: Marginal fit is a very important factor considering the restoration's long-term success. However, adding porcelain to copings can cause distortion and lead to an inadequate fit which exposes more luting material to the oral environment and causes secondary caries. The purpose of this study was to compare the marginal fit of 2 different all-ceramic crown systems before and after porcelain veneering. This study was also intended to verify the marginal fit of crowns originated from green machining of partially sintered blocks of zirconia (Lava CAD/CAM system) and that of crowns obtained through machining of fully sintered blocks of zirconia (Digident CAD/CAM system). MATERIAL AND METHODS: 20 crowns were made per each system and the marginal fit was evaluated through a light microscope with image processing (Accura 2000) at 50 points that were randomly selected. Each crown was measured twice: the first measurement was done after obtaining a 0.5 mm coping and the second measurement was done after porcelain veneering. The means and standard deviations were calculated and statistical inferences among the 2 groups were made using independent t-test and within the same group through paired t-test. RESULTS: The means and standard deviations of the marginal fit were 61.52 +/- 2.88 micrometer for the Digident CAD/CAM zirconia ceramic crowns before porcelain veneering and 83.15 +/- 3.51 micrometer after porcelain veneering. Lava CAD/CAM zirconia ceramic crowns showed means and standard deviations of 62.22 +/- 1.78 micrometer before porcelain veneering and 82.03 +/- 1.85 micrometer after porcelain veneering. Both groups showed significant differences when analyzing the marginal gaps before and after porcelain veneering within each group. However, no significant differences were found when comparing the marginal gaps of each group before porcelain veneering and after porcelain veneering as well. CONCLUSION: The 2 all-ceramic crown systems showed marginal gaps that were within a reported clinically acceptable range of marginal discrepancy.
Ceramics
;
Crowns
;
Dental Porcelain
;
Light
;
Zirconium
3.The Effect of Retinoic Acid on Experimentally-Induced Proliferative Vitreoretinopathy in the Rabbit.
Journal of the Korean Ophthalmological Society 1997;38(10):1755-1763
The proliferative vitreoretinopathy was a complication followed by operation of rhegmatogenous retinal detachment. It was the mot, comon cause of a failure of retinal detachment surgery. It was characterized by the growth of cellular fibrous membrance in detached both retinal side and vitreous and also developed by giant retinal dialysis, posterior segmental trauma, excessive cryotherapy, endophthalmitis, retianl vascular disease. In order to prevent and treat of proliferative vitreoretinopathy, various methods of operation and drugs have been researched. We executed the experiment using the rabbit to observe the effect of retinoic acid that is known by inhibition of migration and proliferation of retinal pigment epithelial cell and fibroblast in vitro. With 121 eyes of rabbit, we induced the proliferative vitreoretinopathy by injecting of human retinal pigment epithelial cell, human fibroblast, and rabbit fibroblast into eyeball of rabbits. The extent of proliferative vitreoretinopathy was compaired by injecting those cells with the group that was injected by retinoic acid and control. The result was that in those cell groups, the extent of proliferative vitreoretinopathy was significantly higher in the rabbit fibroblast group than the other two groups(P<0.05). And in the groups that were injected retinoic acid, when subconjuctivaly injected(0.3mg/0.3ml), proliferative vitreoretinopathy was effectively suppressed and when intravitrealy injected (0.05mg/0.1ml), vitreoretinopathy was more increased than the control group. This result was probably caused by high concentration of retinoic acid in vitreous and further evaluation with various concentration of retinoic acid is needed. In conclusion, we recommend a rabbit fibroblast and subconjunctival injection of retinoic acid for the study on the suppressive effect of proliferative vitreoretinopathy.
Cryotherapy
;
Dialysis
;
Endophthalmitis
;
Epithelial Cells
;
Fibroblasts
;
Humans
;
Rabbits
;
Retinal Detachment
;
Retinaldehyde
;
Tretinoin*
;
Vascular Diseases
;
Vitreoretinopathy, Proliferative*
4.Shear bond strength of veneering porcelain to zirconia and metal cores.
Bu Kyung CHOI ; Jung Suk HAN ; Jae Ho YANG ; Jai Bong LEE ; Sung Hun KIM
The Journal of Advanced Prosthodontics 2009;1(3):129-135
STATEMENT OF PROBLEM: Zirconia-based restorations have the common technical complication of delamination, or porcelain chipping, from the zirconia core. Thus the shear bond strength between the zirconia core and the veneering porcelain requires investigation in order to facilitate the material's clinical use. PURPOSE: The purpose of this study was to evaluate the bonding strength of the porcelain veneer to the zirconia core and to other various metal alloys (high noble metal alloy and base metal alloy). MATERIAL AND METHODS: 15 rectangular (4x4x9mm) specimens each of zirconia (Cercon), base metal alloy (Tillite), high noble metal alloy (Degudent H) were fabricated for the shear bond strength test. The veneering porcelain recommended by the manufacturer for each type of material was fired to the core in thickness of 3mm. After firing, the specimens were embedded in the PTFE mold, placed on a mounting jig, and subjected to shear force in a universal testing machine. Load was applied at a crosshead speed of 0.5mm/min until fracture. The average shear strength (MPa) was analyzed with the one-way ANOVA and the Tukey's test (alpha= .05). The fractured specimens were examined using SEM and EDX to determine the failure pattern. RESULTS: The mean shear strength (+/- SD) in MPa was 25.43 (+/- 3.12) in the zirconia group, 35.87 (+/- 4.23) in the base metal group, 38.00 (+/- 5.23) in the high noble metal group. The ANOVA showed a significant difference among groups, and the Tukey's test presented a significant difference between the zirconia group and the metal group. Microscopic examination showed that the failure primarily occurred near the interface with the residual veneering porcelain remaining on the core. CONCLUSION: There was a significant difference between the metal ceramic and zirconia ceramic group in shear bond strength. There was no significant difference between the base metal alloy and the high noble metal alloy.
Ceramics
;
Collodion
;
Dental Porcelain
;
Fires
;
Fungi
;
Polytetrafluoroethylene
;
Shear Strength
;
Zirconium
5.A study on the fracture strength of collarless metal-ceramic fixed partial dentures.
Jong Wook YOON ; Sung Hun KIM ; Jai Bong LEE ; Jung Suk HAN ; Jae Ho YANG
The Journal of Advanced Prosthodontics 2010;2(4):134-141
PURPOSE: The objective of this study was to evaluate fracture strength of collarless metal-ceramic FPDs according to their metal coping designs. MATERIALS AND METHODS: Four different facial margin design groups were investigated. Group A was a coping with a thin facial metal collar, group B was a collarless coping with its facial metal to the shoulder, group C was a collarless coping with its facial metal 1 mm short of the shoulder, and group D was a collarless coping with its facial metal 2 mm short of the shoulder. Fifteen 3-unit collarless metal-ceramic FPDs were fabricated in each group. Finished FPDs were cemented to PBT (Polybutylene terephthalate) dies with resin cement. The fracture strength test was carried out using universal testing machine (Instron 4465, Instron Co., Norwood MA, USA) at a cross head speed of 0.5 mm/min. Aluminum foil folded to about 1 mm of thickness was inserted between the plunger tip and the incisal edge of the pontic. Vertical load was applied until catastrophic porcelain fracture occurred. RESULTS: The greater the bulk of unsupported facial shoulder porcelain was, the lower the fracture strength became. However, there were no significant differences between experimental groups (P > .05). CONCLUSION: All groups of collarless metal-ceramic FPDs had higher fracture strength than maximum incisive biting force. Modified collarless metal-ceramic FPD can be an alternative to all-ceramic FPDs in clinical situations.
Aluminum
;
Bites and Stings
;
Collodion
;
Dental Porcelain
;
Denture, Partial, Fixed
;
Head
;
Resin Cements
;
Shoulder
6.The effect of low temperature aging on the mechanical property & phase stability of Y-TZP ceramics.
Hyung Tae KIM ; Jung Suk HAN ; Jae Ho YANG ; Jai Bong LEE ; Sung Hun KIM
The Journal of Advanced Prosthodontics 2009;1(3):113-117
STATEMENT OF PROBLEM: Recently Yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) has been introduced due to superior flexural strength and fracture toughness compared to other dental ceramic systems. Although zirconia has outstanding mechanical properties, the phenomenon of decrease in the life-time of zirconia resulted from degradation in flexural strength after low temperature aging has been reported. PURPOSE: The objective of this study was to investigate degradation of flexural strength of Y-TZP ceramics after various low temperature aging treatments and to evaluate the phase stability and micro-structural change after aging by using X-ray diffraction analysis and a scanning electron microscope (SEM). MATERIAL AND METHODS: Y-TZP blocks of Vita In-Ceram YZ (Vita Zahnfabrik, Bad Sackingen, Germany) were prepared in 40 mm (length) x 4 mm (width) x 3 mm (height) samples. Specimens were artificially aged in distilled water by heat-treatment at a temperature of 75, 100, 125, 150, 175, 200, and 225degrees C for 10 hours, in order to induce the phase transformation at the surface. To measure the mechanical property, the specimens were subjected to a four-point bending test using a universal testing machine (Instron model 3365; Instron, Canton, Mass, USA). In addition, X-ray diffraction analysis (DMAX 2500; Rigaku, Tokyo, Japan) and SEM (Hitachi s4700; Jeol Ltd, Tokyo, Japan) were performed to estimate the phase transformation. The statistical analysis was done using SAS 9.1.3 (SAS institute, USA). The flexural strength data of the experimental groups were analyzed by one-way analysis of variance and to detect statistically significant differences (alpha= .05). RESULTS: The mean flexural strength of sintered Vita In-Ceram YZ without autoclaving was 798 MPa. When applied aging temperature at below 125degrees C for 10 hours, the flexural strength of Vita In-Ceram YZ increased up to 1,161 MPa. However, at above 150degrees C, the flexural strength started to decrease. Although low temperature aging caused the tetragonal-to-monoclinic phase transformation related to temperature, the minimum flexural strength was above 700 MPa. CONCLUSION: The monoclinic phase started to appear after aging treatment above 100degrees C. With the higher aging temperature, the fraction of monoclinic phase increased. The ratio of monoclinic/tetragonal + monoclinic phase reached a plateau value, circa 75% above 175degrees C. The point of monoclinic concentration at which the flexural strength begins to decrease was between 12% and 54%.
Aged
;
Aging
;
Aluminum Oxide
;
Ceramics
;
Collodion
;
Dental Porcelain
;
Electrons
;
Humans
;
Phenothiazines
;
Tokyo
;
Water
;
X-Ray Diffraction
;
Yttrium
;
Zirconium
7.Comparison of polymer-based temporary crown and fixed partial denture materials by diametral tensile strength.
Seung Ryong HA ; Jae Ho YANG ; Jai Bong LEE ; Jung Suk HAN ; Sung Hun KIM
The Journal of Advanced Prosthodontics 2010;2(1):14-17
PURPOSE: The purpose of this study was to investigate the diametral tensile strength of polymer-based temporary crown and fixed partial denture (FPD) materials, and the change of the diametral tensile strength with time. MATERIAL AND METHODS: One monomethacrylate-based temporary crown and FPD material (Trim) and three dimethacrylate-based ones (Protemp 3 Garant, Temphase, Luxtemp) were investigated. 20 specimens (the empty set 4 mm x 6 mm) were fabricated and randomly divided into two groups (Group I: Immediately, Group II: 1 hour) according to the measurement time after completion of mixing. Universal Testing Machine was used to load the specimens at a cross-head speed of 0.5 mm/min. The data were analyzed using one-way ANOVA, the multiple comparison Scheffe test and independent sample t test (alpha = 0.05). RESULTS: Trim showed severe permanent deformation without an obvious fracture during loading at both times. There were statistically significant differences among the dimethacrylate-based materials. The dimethacrylate-based materials presented an increase in strength from 5 minutes to 1 hour and were as follows: Protemp 3 Garant (23.16 - 37.6 MPa), Temphase (22.27 - 28.08 MPa), Luxatemp (14.46 - 20.59 MPa). Protemp 3 Garant showed the highest value. CONCLUSION: The dimethacrylate-based temporary materials tested were stronger in diametral tensile strength than the monomethacrylate-based one. The diametral tensile strength of the materials investigated increased with time.
Acrylic Resins
;
Bisphenol A-Glycidyl Methacrylate
;
Collodion
;
Composite Resins
;
Crowns
;
Denture, Partial, Fixed
;
Methacrylates
;
Polymethacrylic Acids
;
Tensile Strength
8.Biomechanical evaluation of dental implants with different surfaces: Removal torque and resonance frequency analysis in rabbits.
Jung Woo KOH ; Jae Ho YANG ; Jung Suk HAN ; Jai Bong LEE ; Sung Hun KIM
The Journal of Advanced Prosthodontics 2009;1(2):107-112
STATEMENT OF PROBLEM: Macroscopic and especially microscopic properties of implant surfaces play a major role in the osseous healing of dental implants. Dental implants with modified surfaces have shown stronger osseointegration than implants which are only turned (machined). Advanced surface modification techniques such as anodic oxidation and Ca-P application have been developed to achieve faster and stronger bonding between the host bone and the implant. PURPOSE: The purpose of this study was to investigate the effect of surface treatment of titanium dental implant on implant stability after insertion using the rabbit tibia model. MATERIAL AND METHODS: Three test groups were prepared: sandblasted, large-grit and acid-etched (SLA) implants, anodic oxidized implants, and anodized implants with Ca-P immersion. The turned implants served as control. Twenty rabbits received 80 implants in the tibia. Resonance frequencies were measured at the time of implant insertion, 2 weeks and 4 weeks of healing. Removal torque values (RTV) were measured 2 and 4 weeks after insertion. RESULTS: The implant stability quotient (ISQ) values of implants for resonance frequency analysis (RFA) increased significantly (P < .05) during 2 weeks of healing period although there were no significant differences among the test and control groups (P > .05). The test and control implants also showed significantly higher ISQ values during 4 weeks of healing period (P < .05). No significant differences, however, were found among all the groups. All the groups showed no significant differences in ISQ values between 2 and 4 weeks after implant insertion (P > .05). The SLA, anodized and Ca-P immersed implants showed higher RTVs at 2 and 4 weeks of healing than the machined one (P < .05). However, there was no significant difference among the experimental groups. CONCLUSION: The surface-modified implants appear to provide superior implant stability to the turned one. Under the limitation of this study, however, we suggest that neither anodic oxidation nor Ca-P immersion techniques have any advantage over the conventional SLA technique with respect to implant stability.
Dental Implants
;
Imidazoles
;
Immersion
;
Nitro Compounds
;
Osseointegration
;
Rabbits
;
Tibia
;
Titanium
;
Torque
9.Radiologic Findings of the Anthrax: Focus on Alimentary Anthrax.
Tae Hun KIM ; Duk Sik KANG ; Won Ho KIM ; Geun Seok YANG ; Sung Woo KIM
Journal of the Korean Radiological Society 1995;33(4):599-603
PURPOSE: To evaluate the radiologic findings of alimentary anthrax. MATERIALS AND METHODS: 19 patients with alimentary anthrax, which was caused by ingestion of contaminated beef, were included in this study. The diagnosis was made .b.y demonstration of Bacillus anthracis in smear and culture of the contaminated meat. We evaluated the clinical manifestations and the findings of thoracic, abdominal radiographs, cervical, abdominal ultrasonograms and abdominal CT scans. RESULTS: Out of the 19 patients with the alimentary infection, 9 had oropharyngeal form, 18 had abdominal form and 8 had combination of oropharyngeal and abdominal form. The patients had general symptoms and signs such as fever, chill, myalgia. Clinical symptoms and signs were sore throat, throat injection, throat ulcer and patch in oropharyngeal form, and nausea, vomiting, abdominal pain, diarrhea, and gross GI bleeding in abdominal form. Radiologic findings included enlarged cervical lymph nodes(36%) in oropharyngeal form, and paralytic ileus(26%), ascites(26%), hepatomegaly(21%), enlarged mesenteric lymph nodes(26%), small bowel wall thickening(5%) in abdominal form. In two patients, late complications occurred as intestinal obstruction due to ileal stricture with perforation, and inflammatory changes of pelvic cavity due to ileovesical fistula. CONCLUSION: Radiologic findings of alimentary anthrax are difficult in differentiation from those of other inflammatory bowel disease, but those radiologic findings with clinical manifestations may be helpful in diagnosis and evaluation of disease process in patients with alimentary anthrax.
Abdominal Pain
;
Anthrax*
;
Bacillus anthracis
;
Constriction, Pathologic
;
Diagnosis
;
Diarrhea
;
Eating
;
Fever
;
Fistula
;
Hemorrhage
;
Humans
;
Inflammatory Bowel Diseases
;
Intestinal Obstruction
;
Meat
;
Myalgia
;
Nausea
;
Pharyngitis
;
Pharynx
;
Tomography, X-Ray Computed
;
Ulcer
;
Ultrasonography
;
Vomiting
10.Esthetic restorations of maxillary anterior teeth with orthodontic treatment and porcelain laminate veneers: a case report.
Ji Eun MOON ; Sung Hun KIM ; Jung Suk HAN ; Jae Ho YANG ; Jai Bong LEE
The Journal of Advanced Prosthodontics 2010;2(2):61-63
If orthodontists and restorative dentists establish the interdisciplinary approach to esthetic dentistry, the esthetic and functional outcome of their combined efforts will be greatly enhanced. This article describes satisfying esthetic results obtained by the distribution of space for restoration by orthodontic treatment and porcelain laminate veneers in uneven space between maxillary anterior teeth. It is proposed that the use of orthodontic treatment for re-distribution of the space and the use of porcelain laminate veneers to alter crown anatomy provide maximum esthetic and functional correction for patients with irregular interdental spacing.
Crowns
;
Dental Porcelain
;
Dentistry
;
Dentists
;
Humans
;
Tooth