1.Prepare the pre-heated composite resin.
Restorative Dentistry & Endodontics 2013;38(2):103-104
No abstract available.
3.Effect of pre-heating on some physical properties of composite resin.
Journal of Korean Academy of Conservative Dentistry 2009;34(1):30-37
The purpose of this study was to evaluate the effect of pre-heating on some physical properties of composite resin. Eighty extracted, noncarious human molars were used in the present study. Four different temperatures of composite resin were used: 4degrees C, 17degrees C, 48degrees C, and 56degrees C. The 4degrees C and 17degrees C values represented the refrigerator storage temperature and room temperature respectively. For 48degrees C and 56degrees C, composite resin was heated to the temperatures. As physical properties of composite resin, shear bond strength, microhardness, and degree of conversion were measured. The data for each group were subjected to one-way ANOVAs followed by the Tukey's HSD test at 95% confidence level. Both in enamel and dentin, among composite resin of 4degrees C, 17degrees C, 48degrees C, and 56degrees C, the pre-heated composite resin up to 56degrees C revealed the highest shear bond strength, and pre-heated composite resin to the higher temperature revealed higher shear bond strength. Microhardness value was also higher with composite resin of higher temperature. Degree of conversion was also higher with composite resin of the higher temperature. In this study, it seems that pre-heating composite resin up to the higher temperature may show higher shear bond strength, higher microhardness value, and higher degree of conversion. Therefore, when using composite resin in the clinic, preheating the composite resin could be recommended to have enhanced physical properties of it.
Dental Enamel
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Dentin
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Hot Temperature
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Humans
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Molar
4.Two imported cases of cutaneous larva migrans.
Jin Woo PARK ; Sang Jin KWON ; Jae Sook RYU ; Eun Kyung HONG ; Jung Uk LEE ; Hee Joon YU ; Myoung Hee AHN ; Duk Young MIN
The Korean Journal of Parasitology 2001;39(1):77-81
Cutaneous larva migrans (CLM) is a rare serpiginous cutaneous eruption caused by accidental penetration and migration in the skin with infective larvae of nematode that normally do not have the human as their host. Although CLM has a worldwide distribution, the infection is most frequent in warmer climates. More recently, they have been increasingly imported from the tropics or subtropics by travelers. We experienced two patients who had pruritic serpiginous linear eruption in their skin for a few weeks after traveling to the endemic areas (Brazil and Thailand, respectively). After the treatment with albendazole, the skin lesions resolved with post-inflammatory hyperpigmentation. We report herein two cases of cutaneous larva migrans successfully treated with albendazole.
Adult
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Albendazole/therapeutic use
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Anthelmintics/therapeutic use
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Child, Preschool
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Female
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Human
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Larva Migrans/*drug therapy/pathology
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Male
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*Travel
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Treatment Outcome
5.Influence of additional etching on shear bond strength of self-etching adhesive system to enamel.
Sun Jin YOO ; Young Kyung KIM ; Jeong Won PARK ; Myoung Uk JIN ; Sung Kyo KIM
Journal of Korean Academy of Conservative Dentistry 2006;31(4):263-268
Recently, self-etching adhesive system has been introduced to simplify the clinical bonding procedures. It is less acidic compared to the phosphoric acid, thus there is doubt whether this system has enough bond strength to enamel. The purpose of this study was to investigate the influence of additional etching on the adhesion of resin composite to enamel. Ninety extracted bovine permanent anterior teeth were used. The labial surfaces of the crown were ground with 600-grit abrasive paper under wet condition. The teeth were randomly divided into six groups of 15 teeth each. Clearfil SE Bond(R), Adper(TM) Prompt L-Pop and Tyrian SPE(TM) were used as self-etching primers. Each self-etching primers were applied in both enamel specimens with and without additional etching. For additional etching groups, enamel surface was pretreated with 32% phosphoric acid (UNI-ETCH, Bisco, Inc., Schaumburg, IL, USA). Hybrid resin composite Clearfil AP-X, (Kuraray Co., Ltd., Osaka, Japan) was packed into the mold and light-cured for 40 seconds. Twenty-four hours after storage, the specimens were tested in shear bond strength. The data for each group were subjected to independent t - test at p < 0.01 to make comparisons among the groups. In Clearfil SE Bond(R), shear bond strength of additional etching group was higher than no additional etching group (p < 0.01). In Adper(TM) Prompt L-Pop and Tyrian SPE, there were no significant difference between additional etching and non-etching groups (p > 0.01). In conclusion, self-etching adhesive system with weak acid seems to have higher bond strength to enamel with additional etching, while self-etching adhesive system with strong acid seems not.
Adhesives*
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Crowns
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Dental Enamel*
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Fungi
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Tooth
6.Long Term Clinical and Radiographical Evaluation of Tunneled Molars.
Young Ran BAEK ; Jin Woo PARK ; Jo Young SUH ; Myoung Uk JIN ; Jae Mok LEE
The Journal of the Korean Academy of Periodontology 2008;38(3):521-528
PURPOSE: Tunneling is a periodontal surgical procedure that creates access for patient cleansing and maintenance within the furcal area of a molar tooth with severe furcation involvement. Up to date, there are few studies about a long term clinical and radiographic stability of tunneling. The purpose of this retrospective study is to evaluate the long term prognosis after tunnel preparation of molars with through and through furcation. MATERIAL AND METHODS: 25 teeth of 23 patients aged 36 to 70 (mean age 51.7) were treated surgically with tunnel preparation. These cases were followed for 2 to 13 years (mean 6.5years) after surgery. Patients were recalled for an evaluation which was based on a questionnaire, a clinical examination, and radiographic analysis. Clinical assessment included plaque index, caries registration, probing pocket depth, bleeding on probing, tooth mobility. Baseline and over 2-year follow-up radiographs were collected and evaluated for this study. RESULT: 3 teeth(12%) had been extracted and 1 tooth(4%) hemisected. Root caries was detected in 3 teeth(12%). Thus 72% of the teeth were still caries free and in function. Clinical parameters including PI, PD, BOP, mobility showed somewhat favourable results. Radiographic furcal bone loss showed no statistically significant difference compared to interproximal crestal bone loss (3.59+/-1.69% vs 3.42+/-2.95%) when root length was used as reference. There was no correlation between root trunk length and furcal bone loss. CONCLUSION: Over 2 years after tunneling procedure, teeth showed a clinically and radiographically stable condition, despite of slight root caries and alveolar bone loss within clinically acceptable range. The tunnel procedure may be considered as a viable periodontal treatment option for molar teeth with severe furcation involvement in individuals following a regular maintenance program.
Aged
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Alveolar Bone Loss
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Follow-Up Studies
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Hemorrhage
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Humans
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Molar
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Periodontitis
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Prognosis
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Surveys and Questionnaires
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Retrospective Studies
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Root Caries
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Tooth
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Tooth Mobility
7.Relationship of tooth mortality and implant treatment in Type 2 diabetes mellitus patients in Korean adults.
Hyun Yub JUNG ; Yong Gun KIM ; Myoung Uk JIN ; Jin Hyun CHO ; Jae Mok LEE
The Journal of Advanced Prosthodontics 2013;5(1):51-57
PURPOSE: The purpose of this study was to to analyze the effect of Type 2 diabetes on tooth mortality, implant treatment and prosthetic status. MATERIALS AND METHODS: 275 Type 2 diabetics and 300 non-diabetics, aged 40-80 years were selected for analysis. The assessment of number of teeth, missing teeth, fixed prostheses (bridge pontics), implants using panoramic radiographs and dental records were carried out. RESULTS: Diabetes mellitus (DM) patients had a higher number of missing teeth (P<.05) and placed implants (P=.074), age (P<.05), male gender percentage (P=.042), smoker percentage (P<.05) than non-DM patients. In univariate analysis, the patients in older group showed significantly higher number of tooth loss rate at the first dental examination than the patients in younger group. Tooth loss rate of smokers did not show higher value than that of non-smokers. When multiple variables including DM, age, smoking, gender were considered together, diabetics and older group patients showed significantly higher tooth loss rate at the first dental examination than non-diabetics and younger group patients, respectively. Smokers and male group did not show a significant difference than non-smokers and female group, respectively. CONCLUSION: Tooth mortality and implant treatment rate were significantly higher in the DM group as indicated by univariate and multivariate logistic regression analysis. Old age groups showed significantly higher odds ratios and tooth loss rate. As diabetics showed the higher tooth loss rate than non-diabetics, diabetics also had more implant restorations than non-diabetics.
Adult
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Aged
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Dental Records
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Diabetes Mellitus
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Diabetes Mellitus, Type 2
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Female
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Humans
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Logistic Models
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Male
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Odds Ratio
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Prostheses and Implants
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Smoke
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Smoking
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Tooth
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Tooth Loss
8.Change of working length in curved canals by various instrumentation techniques.
Jeong Im JO ; Myoung Uk JIN ; Young Kyung KIM ; Sung Kyo KIM
Journal of Korean Academy of Conservative Dentistry 2006;31(1):30-35
To evaluate the change of working length with various instrumentation techniques in curved canals, working length and canal curvature were determined before and after canal instrumentation in buccal or mesial canals of extracted human molars. Stainless steel K-files (MANI(R), Matsutani Seisakusho Co. Takanezawa, Japan), nickel-titanium K-files (Naviflex NT(TM), Brassler, Savannah, USA), ProFile(R), and ProTaper(TM) (Dentsply-Maillefer, Ballaigues, Switzerland) were used to prepare the canals with crown-down technique. In two hand instrumentation groups, coronal flaring was made with Gates Glidden burs. Apical canals were instrumented until apical diameter had attained a size of 30. Positional relation between the tooth apex and the #10 K-file tip was examined by using AutoCAD 2000 (Autodesk Corp., San Rafael. CA, USA) under a stereomicroscope before and after coronal flaring, and after apical instrumentation. Degree of canal curvature was also measured with Schneider's method in radiographs. Data of working length and canal curvature changes were statistically analyzed with one-way ANOVA and Tukey's studentized range test. Working length and canal curvature were decreased significantly in each step in all instrumentation groups. Coronal flaring using Gates Glidden burs in hand instrument groups and whole canal instrumentation using stainless steel hand K-files caused significantly more working length change than in ProFile instrumentation group (p < 0.05). The result of this study demonstrates that all of the above kinds of instrumentation in curved canals cause reduction of working length and canal curvature at each instrumentation steps, and hand instrumentation causes more working length change than ProFile.
Dental Instruments
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Hand
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Humans
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Molar
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Stainless Steel
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Tooth Apex
9.Comparison of screw-in effect for several nickel-titanium rotary instruments in simulated resin root canal.
Jung Hong HA ; Myoung Uk JIN ; Young Kyung KIM ; Sung Kyo KIM
Journal of Korean Academy of Conservative Dentistry 2010;35(4):267-272
Screw-in effect is one of the unintended phenomena that occurs during the root canal preparation with nickel-titanium rotary files. The aim of this study was to compare the screw-in effect among various nickel-titanium rotary file systems. Six different nickel-titanium rotary instruments (ISO 20/.06 taper) were used: K3(TM) (SybronEndo, Glendora, CA, USA), Mtwo (VDW GmbH, Munchen, Germany), NRT with safe-tip and with active tip (Mani Inc., Shioya-gun, Japan), ProFile(R) (Dentsply-Maillefer, Ballaigues, Switzerland) and ProTaper(R) (Dentsply-Maillefer, Ballaigues, Switzerland). For ProTaper(R), S2 was selected because it has size 20. Root canal instrumentations were done in sixty simulated single-curved resin root canals with a rotational speed of 300 rpm and single pecking motion. A special device was designed to measure the force of screw-in effect. A dynamometer of the device recorded the screw-in force during simulated canal preparation and the recorded data was stored in a computer with designed software (LCV-USE-VS, Lorenz Messtechnik GmbH, Alfdorf, Germany). The data were subjected to one-way ANOVA and Tukey's multiple range test for post-hoc test. P value of less than 0.05 was regarded significant. ProTaper(R) produced significantly more screw-in effects than any other instruments in the study (p < 0.001). K3(TM) produced significantly more screw-in effects than Mtwo, and ProFile(R) (p < 0.001). There was no significant difference among Mtwo, NRT, and ProFile(R) (p > 0.05), and between NRT with active tip and NRT with safe one neither (p > 0.05). From the result of the present study, it was concluded, therefore, that there seems significant differences of screw-in effect among the tested nickel-titanium rotary instruments. The radial lands and rake angle of nickel-titanium rotary instrument might be the cause of the difference.
Dental Pulp Cavity
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Root Canal Preparation
10.Evaluation of marginal leakage of bulk fill flowable composite resin filling with different curing time using micro-computed tomography technology.
Eun Ji KIM ; Kyu Bok LEE ; Myoung Uk JIN
Journal of Dental Rehabilitation and Applied Science 2016;32(3):184-193
PURPOSE: To evaluate marginal leakage of bulk fill flowable composite resin filling with different curing time by using microcomputed tomography technology. MATERIALS AND METHODS: 30 previously extracted human molars were randomly divided into 6 groups based upon restorative system and different curing time. Class II cavities (vertical slot cavities) were prepared. An individual metallic matrix was used to build up the proximal wall. The SonicFill or SureFil SDR flow was inserted into the preparation by using 1 bulk increment, followed by light polymerization for different curing times. The different exposure times were 20, 40, and 60 seconds. All specimens were submitted to 5,000 thermal cycles for artificial aging. Micro-CT scanning was performed by using SkyScan 1272. One evaluator assessed microleakage of silver nitrated solution at the resin-dentin interface. The 3D image of each leakage around the restoration was reconstructed with CT-Analyser V.1.14.4. The leakage was analyzed with the Mann-Whitney test. RESULTS: Significant differences were observed between the light curing times, but no significant differences were found between the bulk fill composite resins. Increasing in the photoactivation time resulted in greater microleakage in all the experimental groups. Those subjected to 60 seconds of light curing showed higher microleakage means than those exposed for 20 seconds and 40 seconds. CONCLUSION: Increasing the photoactivation time is factor that may increase marginal microlekage of the bulk fill composite resins. Further, micro-CT can nondestructively detect leakage around the resin composite restoration in three dimensions.
Aging
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Composite Resins
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Humans
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Molar
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Polymerization
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Polymers
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Silver
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X-Ray Microtomography