OBJECTIVES: The purpose of this study was to determine whether pH and time has any influence on the degradation behavior of composite restoration by analyzing the leached monomers of dental composites qualitatively and quantitatively after storage in acetate buffer solution as a function of time using high performance liquid chromatography (HPLC) / mass spectrometer. MATERIALS AND METHODS: Three commercial composite restorative resin materials (Z-250, Heliomolar and Aeliteflo) with different matrix structure and filler composition were studied. Thirty specimens (7mm diameterx2mm thick) of each material were prepared. The cured materials were stored in acetate buffer solution at different pH (4, 7) for 1, 7 and 45days. As a reference, samples of unpolymerized composite materials of each product were treated with methanol (10 mg/ml). Identification of the various compounds was achieved by comparison of their mass spectra with those of reference compound, with literature data, and by their fragmentation patterns. Data were analysed statistically using ANOVA and Duncan's test. RESULTS: 1. Amounts of leached TEGDMA in Aeliteflo were significantly larger than those of UDMA in Z-250 and Heliomolar at experimental conditions of different storage time and pH variation (p < 0.001). 2. As to comparison of the amounts of leached monomers per sorage time, amounts of leached TEGDMA in Aeliteflo and UDMA in Z-250 and Heliomolar were increased in the pH 4 solution more significantly than in the pH 7 solution after 1day, 7days and 45days, respectively (p < 0.001). 3. In total amounts of all the leached monomers with storage times, the overall amounts of pH 4 extracts were larger than those of pH 7 extracts for all resin groups, but there was no significant difference (p > 0.05).
Chromatography, Liquid ; Composite Resins* ; Hydrogen-Ion Concentration* ; Methanol ; Polymers*

The use of flowable composite resins as liners in class II packable composite restoration has been suggested by some manufacturers. However, the contributions of this technique are unproven. The purpose of this study was to compare the gingival microleakage in class II packable composite restorations with or without the use of flowable composite resins as liners. Slot cavities were prepared on both proximals of 80 extracted human molars and randomly assigned to 8 groups of 20 each. The gingival margins were located at 1mm above CEJ in 80 cavities (group1-4) and 1mm below CEJ in 80 cavities (group5-8). The prepared teeth were mounted in the customized tray with adjacent teeth to simulate clinical conditions and metallic matrix band (Sectional matrix) and wooden wedges were applied. After acid etching and application of Single Bond, each group was restored with the following materials using incremental placement technique: Group 1,5 (Filtek P60), group 2, 3, 4 and group 6, 7, 8 (AeliteFlo, TetricFlow, Revolution/Filtek P60). All specimens were thermocycled 500 times between 5degrees C and 55degrees C with 1 mimute dwell time, immersed 2% methylene blue dye for 24 hours and then rinsed with tab water. The specimens were embedded in clear resin and sectioned longitudinally through the center of restoration with a low speed diamond saw. Dye penetration at gingival margin was viewed at 20 magnification and analyzed on a scale of 0 to 4. Kruscal-Wallis One way analysis and Mann-Whitney Rank sum test were used to analyze the results. The results of this study were as follows. 1. The leakage values seen at the enamel margin were significantly lower than those seen at the dentin margin(P<0.05). 2. On the enamel margin, packable composite resins with flowable liners showed lower leakage than those without flowable liners, but there were no significant differences among the four groups(P>0.05). 3. On the dentin margin, four groups demonstrated moderate to severe leakage, and there were no significant differences in leakage values(P>0.05).
Bisphenol A-Glycidyl Methacrylate ; Composite Resins ; Dental Enamel ; Dentin ; Diamond ; Humans ; Matrix Bands ; Methylene Blue ; Molar ; Tooth ; Tooth Cervix ; Water

OBJECTIVES: The purpose of this study was to observe the reaction kinetics and the degree of polymerization of composite resins when cured by different light sources and to evaluate the effectiveness of the blue Light Emitting Diode Light Curing Units (LED LCUs) compared with conventional halogen LCUs. MATERIALS AND METHODS: First, thermal analysis was performed by a differential scanning calorimeter (DSC). The LED LCU (Elipar Freelight, 320 mW/cm2) and the conventional halogen LCU (XL3000, 400 mW/cm2) were used in this study for curing three composite resins (SureFil, Z-250 and AEliteFLO). Second, the degree of conversion was obtained in the composite resins cured according to the above curing mode with a FTIR. Third, the measurements of depth of cure were carried out in accordance with ISO 4049 standards. Statistical analysis was performed by two-way ANOVA test at 95% levels of confidence and Duncan's procedure for multiple comparisons. RESULTS: The heat of cure was not statistically different among the LCUs (p > 0.05). The composites cured by the LED (Exp) LCUs were statistically more slowly polymerized than by the halogen LCU and the LED (Std) LCU (p < 0.05). The composite resin groups cured by the LED (Exp) LCUs had significantly greater degree of conversion value than by the halogen LCU and the LED (Std) LCU (p = 0.0002). The composite resin groups cured by the LED (Std) LCUs showed significantly greater depth of cure value than by the halogen LCU and the LED (Exp) LCU (p < 0.05).
Composite Resins* ; Hot Temperature ; Kinetics ; Polymerization* ; Polymers* ; Spectroscopy, Fourier Transform Infrared

PURPOSE: The varied morphology of the umbilical ring and its surrounding structures, such as the ligamentum teres hepatis, and the median and medial umbilical ligaments, has not been thoroughly investigated. Hence, this study was undertaken to clarify the morphologic variations of these structures. MATERIALS AND METHODS: The anterior abdominal walls were removed en bloc from 57 adult cadavers and dissected under a surgical microscope. RESULTS: One case of umbilical hernia was observed, and the remaining 56 umbilical rings were classified into 3 types: oval or round in 33 cases (Type A, 59.0%), obliterated or slitted in 12 cases (Type B, 21.4%), and completely covered by a connecting band between the ligamentum teres hepatis and umbilical ligaments in 11 cases (Type C, 19.6%). The median and medial umbilical ligaments were classified into four types based on their interrelationships. The most common type was the median umbilical ligament terminated by joining one or both medial umbilical ligaments (Type II, 41.1%). The ligamentum teres hepatis frequently ended by dividing into several branches in the area cranial to the umbilical ring, some of which crossed the umbilical ring. The umbilical fascia covered the umbilical ring in 50.0% of cases, and the rest either not covering the ring or not existing. CONCLUSION: These results are expected to improve our understanding of the anatomy of the umbilical area, and further improve treatments of the umbilical hernia.
Adult ; Aged ; Aged, 80 and over ; Autopsy ; Female ; Hernia, Umbilical/pathology ; Humans ; Ligaments/anatomy & histology/pathology ; Male ; Middle Aged ; Umbilicus/*anatomy & histology/pathology

No abstract available.

In recent years, the synchronous occurrence of two adjacent but histologically distinct tumors arising in the same organ has been reported. The simultaneous development of gastric adenocarcinoma and gastrointestinal stromal tumor (GIST) is very uncommon. The question raised was whether such a coexistence is a simple incidental finding or whether the two neighboring tumors are caused by a same unknown carcinogenic agent. Many doctors may have an interest in this rare condition and we expect further studies will be done in order to determine if there is any association between the two different tumors. We report a unique case of a synchronous, orthotopic occurrence of an early gastric cancer with GIST in the same location that mimicked advanced gastric cancer.
Adenocarcinoma ; Gastrointestinal Stromal Tumors ; Incidental Findings ; Stomach Neoplasms

PURPOSE : To investigate the feasibility of intensity modulated radiotherapy (IMRT) as a method of boost radiotherapy following the initial irradiation by the conventional anterior / posterior opposed beams for centrally located non-small-cell lung cancer through the evaluation of dose distributions according to the various boost methods. MATERIALS AND METHODS : Seven patients with T3 or T4 lung cancer and mediastinal node enlargement who previously received radiotherapy were studied. All patients underwent virtual simulation retrospectively with the previous treatment planning CTs. Initial radiotherapy plans were designed to deliver 40 Gy to the primary tumor and involved nodal regions with the conventional anterior / posterior opposed beams. Two radiation dose levels, 24 and 30 Gy, were used for the boost radiotherapy plans, and 4 different boost methods (a three dimensional conformal radiotherapy (3DCRT), 5, 7, and 9-beams IMRT) were applied to each dose level. The goals of the boost plans were to deliver the prescribed radiation dose to 95% of the planning target volume (PTV) and minimize the volumes of the normal lungs and spinal cord irradiated above their tolerance doses. Dose distributions in the PTVs and lungs, according to the four types of boost plans, were compared in the boost and sum plans, respectively. RESULTS : The percentage of lung volumes irradiated >20 Gy (V20) were reduced significantly in the IMRT boost plans compared with the 3DCRT boost plans at the 24 and 30 Gy dose levels (p=0.007 and 0.031 respectively). Mean lung doses according to the boost methods were not different in the 24 and 30 Gy boost plans. The conformity indexes (CI) of the IMRT boost plans were lower than those of the 3DCRT plans in the 24 and 30 Gy plans (p=0.001 in both). For the sum plans, there was no difference of the dose distributions in the PTVs and lungs according to the boost methods. CONCLUSION : In the boost plans the V20s and CIs were reduced significantly by the IMRT plans, but in the sum plans the effects of IMRT to the dose distributions in the tumor and lungs, like CI and V20, were offset. Therefore, in order to keep the beneficial effect of IMRT in radiotherapy for lung cancer, it would be better to use IMRT as a whole treatment plan rather than as a boost treatment
Humans ; Lung Neoplasms* ; Lung* ; Radiotherapy ; Radiotherapy, Conformal ; Retrospective Studies ; Spinal Cord

PURPOSE: The hepatic arteries of transplant recipients are sometimes in too poor a condition to make a good anastomosis in living donor liver transplantation. The aim of this study was to evaluate the outcome of hepatic artery reconstruction using the recipient's right gastroepiploic artery. METHODS: A total of 153 LDLTs were performed at Seoul National University Hospital from January 1999 to December 2003. In 10 cases, arterial reconstruction was performed by anastomosis of the donor's hepatic artery to the recipient's right gastroepiploic artery. Hepatic artery reconstruction was carried out with the aid of an operating microscope and with using the interrupted Carrel's technique. The adequate blood flow was verified during the operation by the Doppler ultrasonography and also daily for seven days after transplantation by means of Doppler ultrasonography. The median length of the follow-up was 40 months (range: 20~60 months). RESULTS: In seven cases out of ten, the recipient's right gastroepiploic artery was initially used due to arterial thrombosis or because of severe endothelial damage of the recipient's hepatic artery. In the remaining three cases, the graft was revascularized using the recipient's right gastroepiploic artery. In all cases, excellent hepatic arterial flow was confirmed by the Doppler ultrasonography during the operation. Complications related to the hepatic artery were not detected during the follow-up period. CONCLUSION: The recipient's right gastroepiploic artery is a suitable alternative for hepatic artery reconstruction in LDLT.
Follow-Up Studies ; Gastroepiploic Artery* ; Hepatic Artery* ; Humans ; Liver Transplantation* ; Liver* ; Living Donors* ; Seoul ; Thrombosis ; Transplantation ; Transplants ; Ultrasonography, Doppler

PURPOSE: Inappropriate cuff inflations cause many complications. A conventional pilot balloon palpation technique is insufficient to detect high cuff pressures, but is still preferred. Hence, we conducted this study to identify effectiveness, preference and ease of use of a new estimation technique named "passive release technique" for endotracheal tube cuff inflation. METHODS: Twenty-nine nurses inflated cuffs by a pilot balloon palpation technique in manikins inserted with a 7.5 mm endotracheal tube. Then, being educated about passive release techniques, they inflated cuffs using such a passive release technique. Intracuff pressures and air volumes were measured by manometers and syringes. Preference and ease of use between the two methods were scored using a 10-point Likert scale. RESULTS: For the pilot balloon palpation technique, only 4 nurses (13.8%) inflated cuffs within the normal range of pressures (normal: 15 to 30 mb) with an average of 39.3+/-34.0 cmH2O. For the passive release technique, 19 nurses (65.5%) inflated cuffs within the normal range of pressures with an average of 24.2+/-9.3 cmH2O (McNemar's test, p<0.01). In the pilot balloon palpation technique, inflated air volumes of 7.8+/-2.0 ml were not significantly different from inflated air volumes 8.5+/-1.2 ml (p=0.07) for the passive release technique. But the difference was found to be statistically significant in a variance ratio test (F-test) (p<0.01). In view of preference and ease of use between the two methods, mean values were not statistically different, 7.3+/-2.0 vs. 7.0+/-2.0 and 7.0+/-2.3 vs. 7.3+/-2.4, respectively. CONCLUSION: When direct intracuff measurement is not available, a passive release technique using a syringe is an effective and easy method to achieve cuff inflation.
Inflation, Economic ; Intubation ; Manikins ; Palpation ; Reference Values ; Statistics as Topic ; Syringes

Low-viscosity composite resins may produce better sealed margins than stiffer compositions (Kemp-Scholte and Davidson, 1988; Crim, 1989). Flowable composites have been recommended for use in Class V cavities but it is also controversial because of its high rates of shrinkage. On the other hand, in the study comparing elastic moduli and leakage, the microfill had the least leakage (Rundle et al. 1997). Furthermore, in the 1996 survey of the Reality Editorial Team, microfills were the clear choice for abfraction lesions. The purpose of this study was to evaluate the microleakage of 6 compostite resins (2 hybrids, 2 microfills, and 2 flowable composites) with and without load cycling. Notch-shaped Class V cavities were prepared on buccal surface of 180 extracted human upper premolars on cementum margin. The teeth were randomly divided into non-load cycling group (group 1) and load cycling group (group 2) of 90 teeth each. The experimental teeth of each group were randomly divided into 6 subgroups of 15 samples. All preparations were etched, and Single bond was applied. Preparations were restored with the following materials (n=15): hybrid composite resin [Z250(3M Dental Products Inc. St.Paul, USA), Denfil(Vericom, Ahnyang, Korea)], microfill [Heliomolar RO(Vivadent, Schaan, Liechtenstein), Micronew(Bisco Inc. Schaumburg, IL, USA)], and flowable composite [AeliteFlo(Bisco Inc. Schaumburg, IL, USA), Revolution(Kerr Corp. Orange, CA, USA)]. Teeth of group 2 were subjected to occlusal load (100N for 50,000 cycles) using chewing simulator(MTS 858 Mini Bionix II system, MTS Systems Corp., Minn. USA). All samples were coated with nail polish 1mm short of the restoration, placed in 2% methylene blue for 24 hours, and sectioned with a diamond wheel. Enamel and dentin/cementum margins were analyzed for microleakage on a sclale of 0 (no leakage) to 3 (3/3 of wall). Results were statistically analyzed by Kruscal-Wallis One way analysis, Mann-Whitney U-test, and Student-Newmann-Keuls method. (p=0.05) RESULTS: 1. There was significantly less microleage in enamel margins than dentinal margins of all groups. (p<0.05) 2. There was no significant difference between six composite resin in enamel margin of group 1. 3. In dentin margin of group 1, flowable composite had more microleakage than others but not of significant differences. 4. There was no significant difference between six composite resin in enamel margin of group 2. 5. In dentin margin of group 2, the microleakage were R>A=H=M>D>Z. But there was no significant differences. 6. In enamel margins, load cycling did not affect the marginal microleakage in significant degree. 7. In dentin margins, load cycling did affect the marginal microleakage only in Revolution. (p<0.05)
Bicuspid ; Bisphenol A-Glycidyl Methacrylate ; Chimera ; Citrus sinensis ; Composite Resins ; Dental Cementum ; Dental Enamel ; Dentin ; Diamond ; Hand ; Humans ; Mastication ; Methylene Blue ; Nails ; Silicone Elastomers ; Tooth