1.An effect of immediate dentin sealing on the shear bond strength of resin cement to porcelain restoration.
The Journal of Advanced Prosthodontics 2010;2(2):39-45
PURPOSE: The aim of this study was to determine differences in shear bond strength to human dentin using immediate dentin sealing (IDS) technique compared to delayed dentin sealing (DDS). MATERIAL AND METHODS: Forty extracted human molars were divided into 4 groups with 10 teeth each. The control group was light-cured after application of dentin bonding agent (Excite(R) DSC) and cemented with Variolink(R) II resin cement. IDS/SE (immediate dentin sealing, Clearfil(TM) SE Bond) and IDS/SB (immediate dentin sealing, Adapter(TM) Single Bond 2) were light-cured after application of dentin bonding agent (Clearfil(TM) SE Bond and Adapter(TM) Sing Bond 2, respectively), whereas DDS specimens were not treated with any dentin bonding agent. Specimens were cemented with Variolink(R) II resin cement. Dentin bonding agent (Excite(R) DSC) was left unpolymerized until the application of porcelain restoration. Shear strength was measured using a universal testing machine at a speed of 5 mm/min and evaluated of fracture using an optical microscope. RESULTS: The mean shear bond strengths of control group and IDS/SE group were not statistically different from another at 14.86 and 11.18 MPa. Bond strength of IDS/SE group had a significantly higher mean than DDS group (3.14 MPa) (P < .05). There were no significance in the mean shear bond strength between IDS/SB (4.11 MPa) and DDS group. Evaluation of failure patterns indicates that most failures in the control group and IDS/SE groups were mixed, whereas failures in the DDS were interfacial. CONCLUSION: When preparing teeth for indirect ceramic restoration, IDS with Clearfil(TM) SE Bond results in improved shear bond strength compared with DDS.
Bisphenol A-Glycidyl Methacrylate
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Ceramics
;
Collodion
;
Dental Porcelain
;
Dentin
;
Humans
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Molar
;
Resin Cements
;
Shear Strength
;
Tooth
2.Clinical and Histopathological Observation of Porokeratosis.
Sung Jun CHOI ; Hee Joon YU ; Sook Ja SOHN
Korean Journal of Dermatology 1986;24(3):380-385
We observed clinical and histopathological findings of porokeratosis in 16 cases which comprised 2 linear types, 4 superficial disseminat:ed forms, 4 disseminated superficial actinic porokeratosis and 6 plaque types. From the observation, the following results were obtained. l. Clinical results 1) Eleven cases were men, 5 cases were women, and the sex ratio was 2. 2 to 1, age distribution was from 6 to 61 years (mean age: 34. 2years), and the distribution of age of onsets was from 2 to 52 years(mean age of onset' 23. lyears). 2) Four cases had family history of porokeratosis, but linear forms did not. 3) Nine cases had pruritus especially, all cases of DSAP and DSP except 1 case complained pruritus. 4) Tmo cases of DSAP had tendency of summer exacerbations. 2. Histopathological results 1) Cornoid lamellae were prominent in all cases of plaque types and linear types, and minimal in all cases of DSAP and DSP except 1 case. 2) Epidermis between the cornoid lamellae were normal or acanthotic in all cases except 1 case of plaque types and linear types, and were atrophic in 5 cases of 8 cases in DSAP and DSP.
Age Distribution
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Age of Onset
;
Epidermis
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Female
;
Humans
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Male
;
Porokeratosis*
;
Pruritus
;
Sex Ratio
3.Histopathological Observation of Cafe au Lait Spots.
Sung Jun CHOI ; Hee Joon YU ; Sook Ja SOHN
Korean Journal of Dermatology 1986;24(4):506-509
We observed 17 cases of cafe au lait spots histopathplogi ally. Out of 17 cases, 9 cases were neurofibromatosis with neurofibromas, 6 cases were neurofibromatosis without neurofibroma, and 2 cases were normal healthy persons. The results were as follows. l. In all 17 cases, melanin pigment was increased in melanocytes and keratinocytes. 2. Griant pigment granules were identified only in 3 cases of neurofibromatosis with neurofibromas.
Cafe-au-Lait Spots*
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Humans
;
Keratinocytes
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Melanins
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Melanocytes
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Neurofibroma
;
Neurofibromatoses
4.The effects of alveolar bone loss and miniscrew position on initial tooth displacement during intrusion of the maxillary anterior teeth: Finite element analysis.
Sun Mi CHO ; Sung Hwan CHOI ; Sang Jin SUNG ; Hyung Seog YU ; Chung Ju HWANG
The Korean Journal of Orthodontics 2016;46(5):310-322
OBJECTIVE: The aim of this study was to determine the optimal loading conditions for pure intrusion of the six maxillary anterior teeth with miniscrews according to alveolar bone loss. METHODS: A three-dimensional finite element model was created for a segment of the six anterior teeth, and the positions of the miniscrews and hooks were varied after setting the alveolar bone loss to 0, 2, or 4 mm. Under 100 g of intrusive force, initial displacement of the individual teeth in three directions and the degree of labial tilting were measured. RESULTS: The degree of labial tilting increased with reduced alveolar bone height under the same load. When a miniscrew was inserted between the two central incisors, the amounts of medial-lateral and anterior-posterior displacement of the central incisor were significantly greater than in the other conditions. When the miniscrews were inserted distally to the canines and an intrusion force was applied distal to the lateral incisors, the degree of labial tilting and the amounts of displacement of the six anterior teeth were the lowest, and the maximum von Mises stress was distributed evenly across all the teeth, regardless of the bone loss. CONCLUSIONS: Initial tooth displacement similar to pure intrusion of the six maxillary anterior teeth was induced when miniscrews were inserted distal to the maxillary canines and an intrusion force was applied distal to the lateral incisors. In this condition, the maximum von Mises stresses were relatively evenly distributed across all the teeth, regardless of the bone loss.
Alveolar Bone Loss*
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Finite Element Analysis*
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Incisor
;
Tooth*
5.Fixed prosthodontic rehabilitation of maxillary posterior teeth using functionally generated path technique and intraoral digital scan: Case report
Sung-Ho KIM ; Jonghyuk LEE ; Yu-Sung CHOI
The Journal of Korean Academy of Prosthodontics 2020;58(3):228-238
In order to deliver fixed partial denture to a patient successfully, dentist must take into many considerations beforehand. Patient’s occlusal pattern should be fully understood before delivering any type of prosthesis, whether it’s canine guidance or group function occlusion. In order to do so, movement of mandible should be recorded precisely. Introduced by Meyers in 1933, functionally generated path technique (FGP) has been successfully used to record mandibular movement with various materials, such as wax, and utilize it in fabricating precise prosthesis. In the following cases, patients showed secondary caries or endodontic-periodontic lesion on maxillary molars. Root canal treatment and subgingival curettage were done for each patient. Since the long term prognosis of each tooth was questionable, lateral force should be minimized. In order to do so, FGP technique was used to record mandibular movements precisely. Instead of using conventional plaster impression, intra-oral scanning of wax tracing was done to fabricate prosthesis efficiently. After delivery of fixed partial denture, favorable outcome was obtained.
6.Functional and esthetic improvement through reconstruction of anterior guidance using the modified Dahl principle and copy-milled technique of CAD/CAM system: A case report
The Journal of Korean Academy of Prosthodontics 2019;57(2):160-170
The anterior guidance is one of the important factors in prosthodontic treatment of anterior teeth. The lingual surface shape of anterior restorations is so critical that small errors of treatment procedure can cause discomfort of the patient and disharmony of the dentition. If the anterior restorations are achieved harmonious anterior guidance through the fabrication and adjustment of provisional restorations, it is important to accurately reproduce the lingual surface shape of provisional restorations as the final prosthesis. In this case report, it was used the modified Dahl principle and copy-milled technique of computer-aided design/computer-aided manufacturing (CAD/CAM) system for systematic diagnosis and treatment. Therefore, we tried to reconstruct the restoration shape more precisely by setting the appropriate anterior guidance and superimposing the digital image of the abutment teeth and the provisional restorations. Thus, by promoting functional and esthetic recovery, this case report demonstrates satisfying results to both the patients and dentist.
Dentists
;
Dentition
;
Diagnosis
;
Humans
;
Prostheses and Implants
;
Tooth
7.A Clinical Study of Nulliparous Women Aged 40 Years and Older.
Jae Yoo KIM ; Kwang Jun KIM ; Moon Sung SON ; Gill Nam RHO ; Seung Hun CHOI ; Yu Duk CHOI
Korean Journal of Perinatology 1999;10(3):345-352
OBJECTIVE: Our purpose was to compare the pregnancy outcomes of nulliparous women aged 40 years and older with those of nulliparous women under 35 years of age. METHODS: From January 1989 to December 1998 total 57,563 deliveries were seen in Gachon Gil Medical Center. Among them we experienced 59 cases of nulliparas at 40 years and older. These women were compared with 188 young nulliparas under 35 years of age as the control group. The statistical analysis was performed using Chi-square tests, and statistical significance was defined as p<0.05. RESULTS: The incidence rate of elderly nulliparas aged 40 years and older was increased from 0.04% in 1989 to 0.30% in 1998. The age distribution was from 40 years to 45 years. The gravidity of eldery nulliparas was 2.2 in comparison with 1.6 in control group. The incidence of uterine myoma, gestational DM, IUGR and oligohydramnios was significantly high rate in elderly nulliparas. There was significantly high rate of cesarean section in elderly nulliparas(88.1%) in comparison with control group(40.4%). The reasons of cesarean section were her demand(39.0%), CPD(15.3%) and breech presentation(13.6%) in decreasing order. The preterm delivery rate was 10.2% in elderly nulliparas in comparison with 4.3% in the control group. Placenta accreta and uterine atony were significantly high in elderly nulliparas and mean estimated blood loss was also high. There was no difference in 5-minute Apgar score between both group, but there were more cases of neonatal intensive care unit admission in neonates of elderly nulliparas(6.8% vs 0%). CONCLUSION: The incidence of elderly nulliparas is continuously increasing. The elderly nulliparas and their babies are at greater risk than young women. Therefore all elderly nulliparas aged 40 years and older can be regarded as high risk patients and they must be managed with careful attention.
Age Distribution
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Aged
;
Apgar Score
;
Cesarean Section
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Female
;
Fetal Growth Retardation
;
Gravidity
;
Humans
;
Incidence
;
Infant, Newborn
;
Intensive Care, Neonatal
;
Leiomyoma
;
Oligohydramnios
;
Placenta Accreta
;
Pregnancy
;
Pregnancy Outcome
;
Uterine Inertia
8.Iliacus Hematoma with Femoral Neuropathy in Hemophilia: A Case report
Hyung Yeoun CHOI ; Jae Hyung LEE ; Sung Tad CHOI ; Nok Soo KIM ; Chul Joon KIM ; Hee Cheol YU
The Journal of the Korean Orthopaedic Association 1996;31(4):904-908
Hemophilia, a genetically determined disorder, can be divided into hemophilia A and hemophilia B. Hemophilia A, defined as a sex-linked recessive trait hemorrhagic disease of males characterized by a deficiency of factor VIII occurs about seven times more frequently than hemophilia B which is characterized by a deficiency of factor IX. The complications resulting from hemophilia occurs in virtually every system. This paper is concerned with a rare complication of hemophilia, iliacus hematoma with femoral neuropathy. On case of spontaneous hemorrhage of iliacus muscle with femoral neuropathy in hemophilia was decompressed through a small incision with sump drainage under cover of AHF(Anti-hemophilic factor) concentrated plasma cryoperecipitate followed AHF replacement therapy.
Drainage
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Factor IX
;
Factor VIII
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Femoral Neuropathy
;
Hematoma
;
Hemophilia A
;
Hemophilia B
;
Hemorrhage
;
Humans
;
Male
;
Plasma
9.Displacement of a lower third molar into the lateral pharyngeal space.
You Sung CHOI ; Yu Jin JEE ; Hyun Chul SONG
Journal of the Korean Association of Oral and Maxillofacial Surgeons 2004;30(6):551-553
The displacement of an entire tooth into the adjacent anatomical area is an uncommon complication of a tooth extraction. We encountered a 23-year-old woman who had previously undergone surgery under local anesthesia to remove the lower third molar about 12 weeks prior and the upper third molar was extracted 2 days prior to visiting this hospital. Upon admission, she complained of a swallowing discomfort and a mouth opening limitation. Panoramic radiograph and a CT scan revealed a displacement of the entire tooth into the lateral pharyngeal space. The tooth was retrieved via the transoral approach under general anesthesia. The removed tooth had an indentation formed by a dental bur. Therefore, it was concluded that the tooth displaced into the lateral pharyngeal space was the lower third molar. This report describes an unusual case of a third molar that was displaced into the lateral pharyngeal space with a review of the relevant literature.
Anesthesia, General
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Anesthesia, Local
;
Deglutition
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Female
;
Humans
;
Molar, Third*
;
Mouth
;
Tomography, X-Ray Computed
;
Tooth
;
Tooth Extraction
;
Young Adult
10.A Case of Semicircular Lipoatrophy.
Sook Hyun KONG ; Jun Young SEONG ; Seok Hyun HAN ; Yu Sung CHOI ; Ho Seok SUH
Korean Journal of Dermatology 2017;55(1):70-71
No abstract available.