1.Influence of Thickness of Empress 2 Ceramic on Fracture Strength.
Jung Woo KOH ; Jae Ho YANG ; Sun Hyung LEE
The Journal of Korean Academy of Prosthodontics 2000;38(4):446-460
All ceramic restorations have had a more limited life expectancy than metal ceramic crowns because of their lower strength. The relatively lower strength has limited the use of all-ceramic crowns to the areas where occlusal loads are lower. Therefore many researches have been done to increase the strength of all-ceramic crowns. IPS Empress 2 is a new type of lithium disilicate glass-ceramic with enhanced physical characteristics which has been in use clinically since 1998. Previous researches reported that the flexural strength of all-ceramic material was greater than 300MPa, and all-ceramic crowns can be used in staining or layering technique. The objective of this study was to investigate the influence of the thickness of IPS Empress 2 ceramic on fracture strength. Both staining technique and layering technique was investigated. Vita VMK was used as control. For all three groups, five specimens each of 0.8mm, 1.0mm, 1.4mm, 1.8mm, and 2.2mm thickness (a total of 75 specimens) were prepared. Control group: Vita VMK Porcelain specimens were prepared with dentine ceramic and liquid glazing was done. Group I: IPS Empress 2 were prepared with staining technique and stained twice and glazed once. Group II : IPS Empress 2 were prepared with layering technique and glazed after wash firing. The thickness and diameter of the specimen were measured and controlled after specimen preparation. Biaxial Flexure Test (ASTM Standard F394-78) was adopted as this test method produces results least affected by the edge condition of the specimens. Fracture strength was measured with Instron Universal Testing Machine. Conclusions are as follow : 1. The fracture strength was increase in order of control group, test group I, test group II. 2. Fracture strength of the group I(Empress 2 Staining) was 65.54 N in 0.8mm, 155.2 N in 1.0mm, 233.5 N in 1.44mm, 434.5 N in 1.8mm, and 600.1 N in 2.2mm. 3. Fracture strength of the group II (Empress 2 Layering) was 190.0 N in 0.8mm, 283.5 N in 1.0mm, 437.2 N in 1.4mm, 732.0 N in 1.8mm, and 1115.0 N in 2.2mm. 4. No statistical difference was found in flexural strengths according to thickness in a specified group(p>0.05).
Ceramics*
;
Crowns
;
Dental Porcelain
;
Dentin
;
Fires
;
Life Expectancy
;
Lithium
2.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
3.A Case of Lymphangioma Circumscriptum.
Jung Bock LEE ; Chang Jo KOH ; Kil Yun CHO ; Tae Ha WOO
Korean Journal of Dermatology 1973;11(1):49-52
Lymphangioma circumscriptum is a rare disease and the lesions are indistinguishable, clinically and histologically, from lymphangiectasis. The only difference is that lymphangiectasis is usually bilateral and develops in adult or late life, ie, condary to irradiation, surgical interruption, or some malignancies, but lymphangioma circumscriptum is congenital disease or develops soon after birth.
Adult
;
Humans
;
Lymphangiectasis
;
Lymphangioma*
;
Parturition
;
Rare Diseases
4.Pulmonary Thromboembolism Developed in Recovery Period of upper Abdominal Surgery: Case report.
Jong Hwa LEE ; Eun Chi BANG ; Soon Ho NAM ; Shin Ok KOH ; Woo Jung LEE
Korean Journal of Anesthesiology 1997;33(3):567-571
Pulmonary thromboembolism (PTE) is a serious postoperative complication. Prompt diagnosis of PTE is important but it is difficult because clinical manifestations of PTE are not obvious in most cases. A 59 year-old woman received cholecystectomy and choledocholithotomy under general anesthesia. At the 9th postoperative day, syncope, hypoxemia and hypotension were developed suddenly and the patient was transfered to intensive care unit. PTE was suspected with hemodynamic monitoring from pulmonary arterial catheter and echocardiography and diagnosed with lung perfusion scan and venogram of lower extremities. Proper cardiopulmonary support was done and the patient was recovered and discharged in improved condition. In conclusion, if a patient have syncopal attack with shock in postoperative period, PTE must be thought to be an one of possible causes of syncope and thoroughly investigated.
Anesthesia, General
;
Anoxia
;
Catheters
;
Cholecystectomy
;
Diagnosis
;
Echocardiography
;
Female
;
Hemodynamics
;
Humans
;
Hypotension
;
Intensive Care Units
;
Lower Extremity
;
Lung
;
Middle Aged
;
Perfusion
;
Postoperative Complications
;
Postoperative Period
;
Pulmonary Embolism*
;
Shock
;
Syncope
5.Detection of the anti-neural antibodies in the sera of leprosy patients.
Joo Young PARK ; Jung Koo YOUN ; Sang Nae CHO ; Woo Ick YANG ; Choon Myung KOH
Journal of the Korean Society for Microbiology 1992;27(3):239-251
No abstract available.
Antibodies*
;
Humans
;
Leprosy*
6.Treatment of Mycobacterium Abscessus Pulmonary Disease
Korean Journal of Medicine 2019;94(4):343-352
Mycobacterium abscessus is the second most important pathogen in pulmonary disease caused by nontuberculous mycobacteria (NTM), following Mycobacterium avium. Mycobacterium abscessus is classified into three subspecies: M. abscessus subsp. abscessus, M. abscessus subsp. massiliense, and M. abscessus subsp. bolletii. Mycobacterium abscessus is the most difficult to treat NTM due to its resistance to many antibiotics. Treatment should include an initial regimen of 2–3 injectable and oral antibiotics for several weeks or months, followed by inhaled amikacin and 1–3 oral antibiotics, depending on the subspecies and drug susceptibility patterns, including macrolide susceptibility. The continuation phase should be continued for a minimum of 12 months after culture conversion. Suitable injectable antibiotics include amikacin, imipenem, cefoxitin, and tigecycline, while oral antibiotics include macrolides (azithromycin or clarithromycin), clofazimine, linezolid, and moxifloxacin. Surgery can be a useful adjunctive therapy for some patients with refractory disease. However, the overall treatment prognosis is still unsatisfactory. Therefore, novel and more effective interventions are required for the treatment of M. abscessus pulmonary disease.
Amikacin
;
Anti-Bacterial Agents
;
Cefoxitin
;
Clofazimine
;
Humans
;
Imipenem
;
Linezolid
;
Lung Diseases
;
Macrolides
;
Mycobacterium avium
;
Mycobacterium
;
Nontuberculous Mycobacteria
;
Prognosis
7.Treatment of Mycobacterium Abscessus Pulmonary Disease
Korean Journal of Medicine 2019;94(4):343-352
Mycobacterium abscessus is the second most important pathogen in pulmonary disease caused by nontuberculous mycobacteria (NTM), following Mycobacterium avium. Mycobacterium abscessus is classified into three subspecies: M. abscessus subsp. abscessus, M. abscessus subsp. massiliense, and M. abscessus subsp. bolletii. Mycobacterium abscessus is the most difficult to treat NTM due to its resistance to many antibiotics. Treatment should include an initial regimen of 2–3 injectable and oral antibiotics for several weeks or months, followed by inhaled amikacin and 1–3 oral antibiotics, depending on the subspecies and drug susceptibility patterns, including macrolide susceptibility. The continuation phase should be continued for a minimum of 12 months after culture conversion. Suitable injectable antibiotics include amikacin, imipenem, cefoxitin, and tigecycline, while oral antibiotics include macrolides (azithromycin or clarithromycin), clofazimine, linezolid, and moxifloxacin. Surgery can be a useful adjunctive therapy for some patients with refractory disease. However, the overall treatment prognosis is still unsatisfactory. Therefore, novel and more effective interventions are required for the treatment of M. abscessus pulmonary disease.
8.A Demonhstration of a Tracheal Bronchus by Bronchoscopy and Computed Tompgraphy.
Byoung Gu KONG ; Youn Kyung LEE ; Eun Young JEONG ; Woo Ki LEE ; Kwang Woo KIM ; Jung Kon KOH
Journal of the Korean Pediatric Society 2000;43(11):1501-1504
Tracheal bronchus is an aberrant bronchus that arises most often from the right tracheal wall above the carina and is the result of an additional tracheal outgrowth early in embryonic life. It; incidence ranges between 0.1 and 5%. This anomaly is usually diagnosed incidentally during bronchoscopy, bronchography or computed tomography. Occasionally, it represents the underlying etiology for chronic pulmonary disease, especially if it involves the right upper lobe and reflects an abnorrnal pulmonary clearing mechanism. The tracheal bronchus may be associated with other bronchopulmonary anomalies, tracheal stenosis, or Down's syndrome. Asymptornatic tracheal bronchus does not require any treatment. In case of tracheal bronchus associated recurrent right upper lobe diseases, tracheal bronchus therapy should include resection of the aberrant bronchus as well as the lob it supplies. (J Korgan Pediatr Soc 2000;43:1501-1504)
Bronchi*
;
Bronchography
;
Bronchoscopy*
;
Down Syndrome
;
Equipment and Supplies
;
Incidence
;
Lung Diseases
;
Tracheal Diseases
;
Tracheal Stenosis
9.Reevaluation of the thyroid scan for the assessment of pathophysiologic status of thyroid disease.
In Sook WOO ; Jung Il NAH ; Deog Yoon KIM ; Eun Mi KOH ; Sung Woon KIM ; In Myung YANG ; Jin Woo KIM ; Young Seol KIM ; Kwang Woo KIM ; Young Kil CHOI
Korean Journal of Nuclear Medicine 1991;25(1):101-109
No abstract available.
Thyroid Diseases*
;
Thyroid Gland*
10.Reevaluation of the thyroid scan for the assessment of pathophysiologic status of thyroid disease.
In Sook WOO ; Jung Il NAH ; Deog Yoon KIM ; Eun Mi KOH ; Sung Woon KIM ; In Myung YANG ; Jin Woo KIM ; Young Seol KIM ; Kwang Woo KIM ; Young Kil CHOI
Korean Journal of Nuclear Medicine 1991;25(1):101-109
No abstract available.
Thyroid Diseases*
;
Thyroid Gland*