1.Clinical analysis of cranioplasty.
Bae Jeong CHO ; Young Jung HWANG ; Sang Hun HAN
Journal of the Korean Society of Plastic and Reconstructive Surgeons 1992;19(4):626-632
No abstract available.
3.Epidemiological survey on paragonimiasis in Kang Hwa Gun.
Han Jong RIM ; Joon Sang LEE ; Han Sung CHUNG ; Il HYUN ; Kye Hun JUNG
The Korean Journal of Parasitology 1975;13(2):139-151
This study was undertaken to evaluate the status of human paragonimiasis in Kang Hwa Gun, Kyunggi Do, Korea from March 1973 to October 1975 by the use of intradermal screening test with Veronal buffered saline antigen. A total number of 7,352 (male 3,936; female 3,4l6) consisting of 3,447 primary school children, 2,689 middle school students, l,008 high school students of 9 Myuns out of 13 Myuns of this County and 208 residents of all age group in Kilgeong-Ri, Yangdo Myun were examined by the intradermal test with Paragonimus antigen. In order to detect Paragonimus egg, the sputum and the stool examinations were undertaken on the residents in Kilgeong-Ri. The infestation rate of crayfish with Paragonimus metacercaria was also examined in Konneung and Jeongha village in Kilgeong-Ri. The following results were obtained in this survey: As a whole, 16.6 per cent of the examiners showed positive reaction with sexual difference of 16.1% in male and 14.8 per cent in female. In age groups, the highest positive rate showed in middle school age group (17.1 per cent) than primary school (14.0 per cent) and high school age group (11.4 per cent). In regional differences of positive rates, the highest rate (28.4 per cent) showed at Yangdo Myun followed by Kilsang Myun (27.0 per cent), Hwado Myun (25.0 per cent), and Naega Myun(20.8 per cent). In the result of 208 residents Kilgeong-Ri, the positive of 36.1 per cent in male and 20.2 per cent in female. The highest positive rate showed in 10 to 19 age group (41.5 per cent). Among the residents in Kilgeong-Ri, Paragonimus eggs were detected in 11 residents by the sputum and the stool examinations. The infestation rate of crayfsh with Paragonimus metacercariae was 100 per cent (41 out of 41 crayfishes) in Konneung village, and 84.6 per cent (9 out of 13 crayfishes) in Jeongha village, Kilgeong-Ri The fluctuation of the infection rate of crayfish with Paragonimus metacercariae was decreased in Konneung village in 2 years after the treatment with Bilevon against 10 paragonimiasis patients.
parasitology-helminth-trematoda
;
epidemiology-paragonimiasis
;
Paragonimus westermani
;
crayfish-Cambaroides similis
4.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
5.A Clinical Study on the Ovarian Tumors in Pregnancy.
Yong Gul KIM ; Tae Jung KIM ; Hyun Jung LIM ; Sang Joon CHOI ; Chang Hun SONG ; Sei Jun HAN ; Hyuk JUNG
Korean Journal of Perinatology 2001;12(1):35-43
No abstract available.
Pregnancy*
6.Intraosseous Epidermal Cyst of the Distal Phalanx: A Case Report.
Gyu Min KONG ; Joo Yong KIM ; Jung Han KIM ; Dae Hyun PARK ; Kwang Hun AN
The Journal of the Korean Bone and Joint Tumor Society 2014;20(1):22-26
An intraosseous epidermal cyst is a rare benign cystic lesion. It is thought to result from congenital factors or trauma and can lead to bone destruction because the cyst develops at the soft tissue around the bone. Radiological findings of intraosseous epidermal cysts are a well-defined radiolucent lesion, with cortical expansion. It is important to differentiate an intraosseous epidermal cyst with other disease developed at distal phalanx because its clinical and radiological findings are similar. We report two rare cases of intraosseous epidermal cysts that developed at the distal phalanx.
Epidermal Cyst*
7.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
8.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
9.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
10.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