1.Fracture strength between different connector designs of zirconia core for posterior fixed partial dentures manufactured with CAD/CAM system.
Jun Yong SEO ; In Nim PARK ; Keun Woo LEE
The Journal of Korean Academy of Prosthodontics 2006;44(1):29-39
Statements of problem: Zirconia core is used for posterior fixed partial dentures because it's good mechanical properties. Stress is concentrated on connectors in fixed partial dentures, so the proper design of connector areas is needed for adequate mechanical long-term properties of any prosthesis. The area of connector is critical, but tooth size and surrounding soft tissue limit the connector design. PURPOSE: The purpose of this study is to compare fracture strengths between different connector designs of zirconia core for posterior fixed partial dentures manufactured with CAD/CAM system and determining the optimal connector design satisfying strength and hygiene. MATERIAL AND METHOD: The following four groups of 40 posterior fixed partial denture specimens(each group 10) were fabricated as followed; group 1, vertical height of connector is 3mm(control group, all groups have the same condition); group 2, lingual vertical 1mm reinforcement on connector; group 3, lingual vertical 2mm reinforcing on connector and group 4, lingual vertical 3mm reinforcing on connector. Specimens were subjected to compressive loading on the central fossa of pontic by instron. SEM was used to identify the initial crack and characterize the fracture mode. RESULTS: The results were as follows: 1. The mean fracture load of the non-lingual reinforcing group was 1212N and the lingual vertical 1mm reinforcing group was 1510N, the lingual vertical 2mm reinforcing group was 1882N, the lingual vertical 3mm reinforcing group was 1980N. 2. The reinforcing groups were statistically significant compared to non-reinforcing groups(P<0.001). 3. There were 2, 3mm reinforcing groups that were statistically significant compared to 1mm reinforcing groups(P<0.001), and the 3mm reinforcing group was not statistically significant compared to 2mm reinforcing groups(P>0.05) 4. Fractures were initiated in gingival embrasures of connectors and processed to the loading site. CONCLUSION: In this study, lingual reinforcement of connector for improved strength of zirconia based fixed partial denture is nessasary. And long-term study for clinical application is required.
Denture, Partial, Fixed*
;
Hygiene
;
Prostheses and Implants
;
Tooth
2.Fracture strength between different connector designs of zirconia core for posterior fixed partial dentures manufactured with CAD/CAM system.
Jun Yong SEO ; In Nim PARK ; Keun Woo LEE
The Journal of Korean Academy of Prosthodontics 2006;44(1):29-39
Statements of problem: Zirconia core is used for posterior fixed partial dentures because it's good mechanical properties. Stress is concentrated on connectors in fixed partial dentures, so the proper design of connector areas is needed for adequate mechanical long-term properties of any prosthesis. The area of connector is critical, but tooth size and surrounding soft tissue limit the connector design. PURPOSE: The purpose of this study is to compare fracture strengths between different connector designs of zirconia core for posterior fixed partial dentures manufactured with CAD/CAM system and determining the optimal connector design satisfying strength and hygiene. MATERIAL AND METHOD: The following four groups of 40 posterior fixed partial denture specimens(each group 10) were fabricated as followed; group 1, vertical height of connector is 3mm(control group, all groups have the same condition); group 2, lingual vertical 1mm reinforcement on connector; group 3, lingual vertical 2mm reinforcing on connector and group 4, lingual vertical 3mm reinforcing on connector. Specimens were subjected to compressive loading on the central fossa of pontic by instron. SEM was used to identify the initial crack and characterize the fracture mode. RESULTS: The results were as follows: 1. The mean fracture load of the non-lingual reinforcing group was 1212N and the lingual vertical 1mm reinforcing group was 1510N, the lingual vertical 2mm reinforcing group was 1882N, the lingual vertical 3mm reinforcing group was 1980N. 2. The reinforcing groups were statistically significant compared to non-reinforcing groups(P<0.001). 3. There were 2, 3mm reinforcing groups that were statistically significant compared to 1mm reinforcing groups(P<0.001), and the 3mm reinforcing group was not statistically significant compared to 2mm reinforcing groups(P>0.05) 4. Fractures were initiated in gingival embrasures of connectors and processed to the loading site. CONCLUSION: In this study, lingual reinforcement of connector for improved strength of zirconia based fixed partial denture is nessasary. And long-term study for clinical application is required.
Denture, Partial, Fixed*
;
Hygiene
;
Prostheses and Implants
;
Tooth
3.CT and MR findings of mycotic infection of the paranasal sinus: differentiation from sinonasal neoplasm.
Kil Woo LEE ; Hyo Keun LIM ; Gwy Suk SEO ; Suk Soo BAE ; Shin Hyung LEE
Journal of the Korean Radiological Society 1992;28(2):176-181
When a soft tissue mass in the bony wall of the paranasal sinus is present, it is difficult to make a distinction between tumor and inflammatory mass on CT. Fungal sinusitis may have soft tissue attenuation on the bony wall of the sinus, bony sclerosis, focal bony destruction, and calcific area on CT. This is a report of four proven cases of fungal sinusitis, asperogillosis in 3 cases and mucormycosis in 1 case, All 4 patients had CT and one patient had MRI, On CT, bony sclerosis and destruction were well visualized in all cases. On MRI, mycetoma in the maxillary sinus was hypointense on T1 weighted images and more hypointense on T2 weighted images. Although CT appears to be the best modality for initial examination of the patient with sinusitis, the differentiation of fungal sinusitis from tumor mass or other entity may be better accomplished with MRI.
Humans
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Magnetic Resonance Imaging
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Maxillary Sinus
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Mucormycosis
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Mycetoma
;
Sclerosis
;
Sinusitis
4.The Role of nm23-H1 Gene in Urologic Cancer (II): Expression and Mutation of nm23-H1 Gene in Urothelial Cancer.
Woo Chul MOON ; Young Jin KEE ; Kyung Keun SEO
Korean Journal of Urology 1996;37(6):607-618
BACKGROUND AND PURPOSE: We had previously demonstrated by immunohistochemical study (IHS) that nm23-H1 gene may play an important role in disease prognosis as well as its participation in metastasis of urothelial cancer. The purpose of present study was 1) to reexamine the role of nm23-H1 gene in urothelial cancers at molecular level, 2) to identify the molecular mechanism of decreased immunoreactivity for nm23-H1 protein in metastatic urothelial cancers, and 3) to identify whether IHS is reliable in studying the expression of nm23-H1. MATERIALS AND METHODS: We studied expression level and mutation profiles of nm23-H1 gene in 25 fresh surgical specimens of urothelial cancer by reverse transcription polymerase chain reaction(RT-PCR)-Southern blotting analysis, and PCR of genomic DNA followed by single strand conformation polymorphism and sequencing analysis. The results of RT-PCR-Southern blotting were comparatively analyzed with those of IHS. RESULTS: mRNA transcript levels of nm23-H1 gene were significantly decreased in tumor tissues with metastasis as compared with those without metastasis. The transcript levels of nm23-H1 gene were also significantly decreased in metastatic tumor tissues as compared with primary tumor tissues. Point mutation of nm23-H1 gene was detected in only 1 of 13 urothelial cancer tissues with metastasis, whereas, mutation was observed in none of those without metastasis. The results of IHS corresponded with those of RT-PCR-Southern blotting analysis in 23 of 25 specimens. CONCLUSIONS: The nm23-H1 gene may play an important role in metastasis of urothelial cancer. Decreased transcription at mRNA level may be a major molecular mechanism of loss of immunoreactivity for nm23-H1 protein in urothelial cancer. IHS used in the present study may be a clinically useful method to study the expression of nm23-H1 and to predict metastasis potential and prognosis of urothelial cancers.
DNA
;
Neoplasm Metastasis
;
Point Mutation
;
Polymerase Chain Reaction
;
Prognosis
;
Reverse Transcription
;
RNA, Messenger
;
Urologic Neoplasms*
5.Comparative Analysis of Conventional Transurethral Resection of the Prostate and Laser Induced Prostatectomy.
Woo Chul MOON ; Bo Sang NOH ; Kyung Keun SEO
Korean Journal of Urology 1996;37(5):521-530
BACKGROUND AND PURPOSE: Laser induced prostatectomy(LIP) has recently been considered as safe alternative to conventional transurethral resection of the prostate(TURP) in the surgical treatment of BPH. However, the value of LIP remains incompletely defined. We herein have performed a prospective study to compare TURP and LIP in treatment efficacy, safety and costs to define the value of LIP. MATERIALS AND METHODS: 113 patients with BPH who were candidates of TURP were randomized to undergo TURP or LIP and were adequately followed up for more than 1 year. There were no significant differences in preoperative clinical characteristics between 55 patients who underwent TURP and 58 patients who underwent LIP. For the LIP procedure, Nd:YAG was used in 42 patients and diode laser in 16 patients, respectively. 37 patients were treated by contact LIP only, and 21 with hybrid procedures of contact LIP and noncontact LIP using side firing laser fiber or interstitial laser fiber. Seven patients underwent LIP under local anesthesia at the outpatient department. RESULTS: International prostate symptom score(IPSS) and peak urinary flow rate(Qmax) were significantly improved at 3 months, 6 months, and 1 year after LIP as well as after TURP. There were no significant difference between TURP group(85.4%) and LIP group(87.9%) in treatment success rate as defined by improvement of IPSS and Qmax as well as patient's content for the surgical outcome. Nine(16.4%) and two(3.6%) of the patients who underwent TURP and none of the patients who LIP underwent developed ignificant bleeding and electrolyte imbalance, respectively. There were no significant difference in postoperative incidence of retrograde ejaculation, infection and urethral stricture between the two groups. Compared to TURP, the LIP procedure required significantly shorter hospitalization(6.8 vs 4.5 days) and catheterization(4.1 vs 2.6 days, all p<0.0l). There was no significant difference in total treatment cost between the two groups. CONCLUSIONS: LIP may be comparable to TURP in terms of short term treatment efficacy and cost effectiveness. LIP may be better than TURP in terms of safety and shortened hospitalization and catheterization. Further studies are necessary on long-term outcomes of LIP."
Anesthesia, Local
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Catheterization
;
Catheters
;
Cost-Benefit Analysis
;
Ejaculation
;
Fires
;
Health Care Costs
;
Hemorrhage
;
Hospitalization
;
Humans
;
Incidence
;
Lasers, Semiconductor
;
Lip
;
Male
;
Outpatients
;
Prospective Studies
;
Prostate*
;
Prostatectomy*
;
Transurethral Resection of Prostate
;
Treatment Outcome
;
Urethral Stricture
6.Clinical Significance of Ultrasonography for Detection of Hip Joint Effusion in Children: Analysis of the 23 Cases of Transient Synovitis of the Hip
Keun Woo KIM ; Han Suk KO ; Suk Kee TAE ; Dae Yeung KIM ; Lee Suk SEO
The Journal of the Korean Orthopaedic Association 1988;23(2):542-548
Transient synovitis of the hip in children is a non-specific inflammatory and self-limited condition. It is also the most common cause of painful hip in children under ten years of age. Despite of the benign prognosis, there are many difficulties in distinguishing it from other diseases of the hip joint. It remains a common diagnostic problem for clinician because the clinical symptoms, physical findings, and conventional radiography is not pathognomonic of the condition. The authors paid attention to the increase of effusion in the affected hip and studied the value of the hip ultrasonography in 24 cases of transient synovitis from August 1985 to July 1987. The results are summerized as follows : 1. The ratio of male to female was 7 to 1, average age was 7.9 yrs, average hospitalization period was 4.5 days. 2. In simple X-ray studies, no bony change was detectable except for soft tissue signs in 68% of the cases. 3. Capsule-to-bone distance in sagittal ultrasonographic section revealed abnormal increase in 87.5% of the affected hip. 4. Average capsule-to-bone distance of affected hip joint was 7.50 mm, while that of the normal hip was 4.26 mm. 5. As shown in the above studies, ultrasonography can be considered good noninvasive technique in detection and follow-up of hip effusion. So, it is thought to be a valuable method in the diagnosis of transient synovitis of the hip in children.
Child
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Diagnosis
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Female
;
Follow-Up Studies
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Hip Joint
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Hip
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Hospitalization
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Humans
;
Male
;
Methods
;
Prognosis
;
Radiography
;
Synovitis
;
Ultrasonography
7.Successful Recanalization of Subacute In-Stent Thrombosis after Carotid Artery Stenting.
Juyeon KIM ; Woo Keun SEO ; Sang Il SUH
Journal of the Korean Neurological Association 2011;29(4):382-384
No abstract available.
Angioplasty
;
Carotid Arteries
;
Stents
;
Thrombosis
8.Sonographic characterization of tenosynovitis.
Gwy Suk SEO ; Hyo Keun LIM ; In Jae LEE ; Kil Woo LEE ; Sang Hoon BAE ; Kyung Hwan LEE
Journal of the Korean Radiological Society 1992;28(2):275-280
Tenosynovitis of the extremities is not uncommon but its diagnosis is not easy owing to its non-specific clinical manifestation. Thus it was beyond the field of imaging diagnosis so far. Recently the development of high resolution ultrasonogram has aided preoperative imaging diagnosis of tenosynovitis. The authors performed a retrospective review of 27 patients who had ultrasonography due to tendon pathology(including 18 tenosynovites) by oserving sonographic finding and evaluation the diagnostic value of each finding. The overall diagnostic accuracy was 81.1% and common sonographic findings were focal swelling of the tendon. well-defined margin of the lesion, preserved fibrillar pattern, echo change of the lesion site and fluid collection. Above al,. fluid collection was the only statistically significant criterion for diagnosis of tenosynovitis (p<0.05). But its sensitivity was as low as 50%. In conclusion the ultrasonography is useful in diagnosis of tenosynovitis and fluid collection is of diagnostic value, but the differentiation between nodular tenosynovitis without fluid collection and other benign tumor is still beyond the scope of ultrasonographic diagnosis.
Diagnosis
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Extremities
;
Humans
;
Retrospective Studies
;
Tendons
;
Tenosynovitis*
;
Ultrasonography*
9.Clinical and radiographical evaluation of implant-supported fixed partial prostheses.
Ji Young SEO ; June Sung SHIM ; Jae Hoon LEE ; Keun Woo LEE
The Journal of Korean Academy of Prosthodontics 2006;44(4):394-403
Statement of problem: A conventional 3-unit fixed partial denture design with a pontic between two retainers is the most commonly used. However, in cases where the mental nerve is in close proximity to the second premolar, a cantilever design can be considered. As such, logical and scientific evidence is lacking for the number and position of implants to be placed for partially edentulous patients, and no clear-cut set of treatment principles currently exist. Purpose: The purpose of this study was to evaluate prognosis of implant-supported fixed partial dentures, and to compare changes in bone level which may rise due to the different factors. Material and method: The present study examined radiographical marginal bone loss in patients treated with implant-supported fixed partial dentures(87 prostheses supported by 227 implants) and evaluated the influence of the span of the pontic, type of the opposing dentition. Clinical complications were studied using a retrospective method. Within the limitation of this study, the following result were drawn. Result: 1. Seven of a total of 227 implants restored with fixed prostheses failed, resulting in a 96.9% success rate. 2. Complications encountered during recall appointments included dissolution of temporary luting agent (17 cases), porcelain fracture (8 cases), loosened screws (5 cases), gingival recession (4 cases), and gingival enlargement (1 case). 3. Marginal bone loss, 1 year after prosthesis placement, was significant(P<0.05) in the group that underwent bone grafting, however no difference in annual resorption rate was observed afterwards. 4. Marginal bone loss, 1 year post-placement, was greater in cantilever-type prostheses than in centric pontic protheses(P<0.05). 5. Marginal bone loss was more pronounced in posterior regions compared to anterior regions(P<0.05). 6. The degree of marginal bone loss was proportional to the length of the pontic(P<0.05). Conclusion: The success rate of implant-supported fixed partial dentures, including marginal bone loss, was satisfactory in the present study. Factors influencing marginal bone loss included whether bone graft was performed, location of the pontic(s), location of the surgical area in the arch, pontic span. Long-term evaluation is necessary for implant-supported fixed partial dentures, as are further studies on the relationship between functional load and the number of implants to be placed.
Appointments and Schedules
;
Bicuspid
;
Bone Transplantation
;
Dental Cements
;
Dental Porcelain
;
Dentition
;
Denture, Partial, Fixed
;
Gingival Recession
;
Humans
;
Logic
;
Prognosis
;
Prostheses and Implants*
;
Retrospective Studies
;
Transplants
10.A Case of Congenital Dyserythropoietic anemia Type IV.
Hwa Young JEON ; Hwang Min KIM ; Baek Keun LIM ; Duk Woo PARK ; Myung Seo KANG ; Young Kun DEUNG
Journal of the Korean Pediatric Society 1995;38(5):702-706
No abstract available.
Anemia, Dyserythropoietic, Congenital*