PURPOSE: This study evaluated the depth of cure of resin composite cured by light through a translucent fiber post. MATERIALS AND METHODS: The opaque plastic tubes in various lengths of 2, 4, 6, 8, 10, 12, 14 mm. were filled with resin composite in which two different translucent fiber posts were inserted into the center and photo-polymerized for 40 seconds. The degree of conversion of the cured composite at bottom surface were examined using Fourier transform infrared attenuated total reflection spectrometer (FTIR/ATR) at 0.1, 0.5 and 1.0 mm apart from the post surface. RESULTS: The degree of conversion of the 0.1 mm, 0.5 mm, 1.0 mm apart from the post surface was highest at the 2 mm level and continuously decreased when the distance from the light source was increased and drastically decreased when the depth from the top of the post was greater than 4-6 mm. For each level, the highest degree of conversion was at 0.1 mm from the post surface and decreased continuously when the distance apart from the post surface was increased. CONCLUSION: The quantity of light transmission depends on the type of post and the light transmission capability of the post, especially after 4-6 mm depth and the area further apart from the post surface, are insufficient for clinical light activation of resin composite.
Fourier Analysis ; Plastics

No abstract available.
Finite Element Analysis* ; Plastics* ; Titanium*

PURPOSE: The aim of this study is to evaluate and compare the stress distribution in Locator attachments in mandibular two-implant overdentures according to implant locations and different loading conditions. MATERIALS AND METHODS: Four three-dimensional finite element models were created, simulating two osseointegrated implants in the mandible to support two Locator attachments and an overdenture. The models simulated an overdenture with implants located in the position of the level of lateral incisors, canines, second premolars, and crossed implant. A 150 N vertical unilateral and bilateral load was applied at different locations and 40 N was also applied when combined with anterior load at the midline. Data for von Mises stresses in the abutment (matrix) of the attachment and the plastic insert (patrix) of the attachment were produced numerically, color-coded, and compared between the models for attachments and loading conditions. RESULTS: Regardless of the load, the greatest stress values were recorded in the overdenture attachments with implants at lateral incisor locations. In all models and load conditions, the attachment abutment (matrix) withstood a much greater stress than the insert plastic (patrix). Regardless of the model, when a unilateral load was applied, the load side Locator attachments recorded a much higher stress compared to the contralateral side. However, with load bilateral posterior alone or combined at midline load, the stress distribution was more symmetrical. The stress is distributed primarily in the occlusal and lateral surface of the insert plastic patrix and threadless area of the abutment (matrix). CONCLUSION: The overdenture model with lateral incisor level implants is the worst design in terms of biomechanical environment for the attachment components. The bilateral load in general favors a more uniform stress distribution in both attachments compared to a much greater stress registered with unilateral load in the load side attachments. Regardless of the implant positions and the occlusal load application site, the stress transferred to the insert plastic is much lower than that registered in the abutment.
Bicuspid ; Clothing ; Denture, Overlay* ; Finite Element Analysis ; Incisor ; Mandible ; Plastics

The most important factor in clinical development of respiratory care has been the clinical availabiTity of blood gas and pH measurement and it is important to get the accurate values of those. There can be an error to get the value of PCO2, PO2 and pH by dilutional effect of liquid-Naheparin that is usally used as an anticoagulant. We compared values of 20 arterial blood gases sampled with 1 cc plastic syringe utilizing liquid-Na-heparin with those ones sampled with 1 cc arterial blood gas kits which were pre-filled with dry-Lithium-heparin. The results were as follows; 1) There are no difference in values of PO2 and pH between two groups. 2) The value of PCO2 sampled with 1 cc plastic syringe utilizing liquid-Na-heparin is 1.62 torr less than the value of that with 1 cc arterial blood gas kits which were pre-filled with dry-Lithium-heparin (p<0.05).
Blood Gas Analysis* ; Gases ; Hydrogen-Ion Concentration ; Plastics ; Syringes*

In order to solve the problem of weak correlation between quality control components and efficacy of Glycyrrhizae Radix et Rhizoma, this study detected the interaction between small molecular chemical components of Glycyrrhizae Radix et Rhizoma and total proteins of various organs of mice by fluorescence quenching method to screen potential active components. The 27 chemical components in Glycyrrhizae Radix et Rhizoma were detected by HPLC and their deletion rates in 34 batches of Glycyrrhizae Radix et Rhizoma were calculated. Combined with the principle of component effectiveness and measurability, the potential quality markers(Q-markers) of Glycyrrhizae Radix et Rhizoma were screened. RAW264.7 macrophage injury model was induced by microplastics. The cell viability and nitric oxide content were detected by CCK-8 and Griess methods. The levels of inflammatory factors(TNF-α, IL-1β, IL-6, CRP) and oxidative stress markers(SOD, MDA, GSH) were detected by the ELISA method to verify the activity of Q-markers. It was found that the interaction strength between different chemical components and organ proteins in Glycyrrhizae Radix et Rhizoma was different, reflecting different organ selectivity and 18 active components were screened out. Combined with the signal-to-noise ratio of the HPLC chromatographic peaks and between-run stability of the components, seven chemical components such as liquiritin apioside, liquiritin, isoliquiritin apioside, isoliquiritin, liquiritigenin, isoliquiritigenin and ammonium glycyrrhizinate were finally screened as potential Q-markers of Glycyrrhizae Radix et Rhizoma. In vitro experiments showed that Q-markers of Glycyrrhizae Radix et Rhizoma could dose-dependently alleviate RAW264.7 cell damage induced by microplastics, inhibit the secretion of inflammatory factors, and reduce oxidative stress. Under the same total dose, the combination of various chemical components could synergistically enhance anti-inflammatory and antioxidant effects compared with the single use. This study identified Q-markers related to the anti-inflammatory and antioxidant effects of Glycyrrhizae Radix et Rhizoma, which can provide a reference for improving the quality control standards of Glycyrrhizae Radix et Rhizoma.
Mice ; Animals ; Antioxidants/analysis* ; Microplastics/analysis* ; Plastics/analysis* ; Rhizome/chemistry* ; Drugs, Chinese Herbal/analysis* ; Glycyrrhiza/chemistry* ; Anti-Inflammatory Agents/analysis*

A 34 year old male patient underwent emergency operation of tracheal resection and primary end-to-end anastomosis to correct of tracheal stenosis following tracheostomy. On admission, a No. 3 Magill plastic Portex tracheostomy tube had been placed in the previous tracheostomy opening. Stenotic narrowing was noted 4 cm above carina. Despite of severe narrowing of the lesion, anesthetic course was uneventful with nitrous oxide, oxygen and halothane by controlled respiration and serial blood gas analyses. Postoperative courses were also favorable with adequate respiratory cares. It is mandatory to perform serial blood gas analyses for the management of corrective operation on tracheal stenosis.
Adult ; Blood Gas Analysis ; Emergencies ; Halothane ; Humans ; Male ; Nitrous Oxide ; Oxygen ; Plastics ; Respiration ; Tracheal Stenosis* ; Tracheostomy

Arterial blood gas analysis is essential laboratory test in monitoring of acid-base balance and respiratory care, but it has been known that there was many variabilities according to method of sampling and care before analysis. We compared the effects of liquid Na heparin and dry Li-heparin on blood gas analysis, hemoglobin and electrolytes, and studied in 25 patients who were taken elective operation with radial arterial eannulation. The samples were obtained from radial artery; sample 1, drawn to a total volume of 1 cc with 2cc plastic syringe utilizing liquid Na-heparin; sample 2, drawn to a total volume of 2 cc with 2 cc plastic syringe utilizing liquid Na-heparin ; sample 3, drawn to a total volume of 1 cc with Bard parker Preset 1 cc kit that pre-filled dry Li-heparin; control value, sampled arterial blood without heparin for measurement of hemoglobin and electrolytes. These samples were analyzed with minimum error, as possible. We obtained the following results. 1) There was no atatistical difference in pH, PCO2, PO2 and hemoglobin in each sample. 2) The value of Na+ and K+ were no statistical differences in sample 1,2 and 3, but sig- nificantly lower level than control value (P<0.01). 3) The Ca2+ level was significantly lower in sample 1 and 2(P<0.01) and not significantly different in sample 3 when compared with the control value. The Ca level was significantly higher in sample 2 and 3 when compared with sample 1 (P<0.01). So we conclude that arterial blood gas analysis and hemoglobin level showed no statistical difference between the liquid Na heparin and the dry Li-heparin. Heparin is not suitable for Na+ and K+ measurement. Low dose liquid Na heparin and dry Li heparin is reliable for obtaining Ca2+ level.
Acid-Base Equilibrium ; Blood Gas Analysis* ; Electrolytes ; Heparin ; Humans ; Hydrogen-Ion Concentration ; Plastics ; Radial Artery ; Syringes

OBJECTIVE: The aims of this study were to measure and compare the facial dimensions of the Miss Korea pageant contestants and a selected group of women from the general population by using three-dimensional (3D) image analysis, as well as to compare various facial ratios to the golden ratio within each group. METHODS: Three-dimensional images of 52 Miss Korea pageant contestants (MK group) and 41 young female adults selected from the general population (GP group) were acquired. Fifty-four variables and ratios were measured and calculated. Intergroup comparisons were performed using multivariate analysis of variance. RESULTS: Compared to the GP group, the MK group showed greater total facial height and eye width, lesser lower-facial height, and lesser facial, lower-facial, and nasal widths. Moreover, compared to the GP group, the MK group had more protruded noses with greater nasolabial angle, greater vertical curvature of the foreheads, lesser horizontal curvature of the cheek, and lesser lower-lip-and-chin volume. CONCLUSIONS: The MK group had longer faces but smaller lower lips and chins than did the GP group. The golden ratio was not matching the current facial esthetic standards. These data might be beneficial for treatment planning of patients undergoing orthognathic and plastic surgeries.
Adult ; Cheek ; Chin ; Esthetics* ; Female ; Forehead ; Humans ; Imaging, Three-Dimensional ; Korea* ; Lip ; Multivariate Analysis ; Nose ; Plastics

OBJECTIVE: The aim of this study was to identify diffrentially regulated genes after the treatment of fluoxetine in rat C6 glioma cells using cDNA microarray chip techniques and real-time RT-PCR. METHODS: Cells were incubated for 24 hours, and for 72 hours with or without 10 uM fluoxetine. Total RNAs extracted from cells were reversely transcribed to cDNA. These cDNA were used to carry out cDNA microarray chip. A part of the up-/down-regulated genes in cDNA microarray result were confirmed by real-time RT-PCR. RESULTS: 1) Genes in fluoxetinetreated cells for 72 hours (chronic treatment) were more regulated than that in fluoxetine-treated cells for 24 hours (acute treatment). 2) The expression level of Gs gene in fluoxetine-treated cells for 24 hours hardly altered, but that of Gs in fluoxetine-treated cells for 72 hours significantly increased. The expression of Gi2 also decreased in 72 hours in relation to 24 hours after the administration of fluoxetine. 3) The expression level of NCAM140 gene in fluoxetine-treated cells was higher than that in control cells. CONCLUSION: We identified genes (Gs, Gi2 and NCAM140) related to neural plasticity and intracellular signal transduction cascade from our result. This implies that fluoxetine may inhibit atrophy or death of impaired neural cells by promoting neurite outgrowth.
Animals ; Atrophy ; DNA, Complementary ; Fluoxetine* ; Glioma* ; Neurites ; Oligonucleotide Array Sequence Analysis ; Plastics ; Rats* ; RNA ; Signal Transduction

STATEMENT OF PROBLEM: Loosening or fracture of the abutment screw is one of the common problems related to the dental implant. Generally, in order to make the screw joint stable, the preload generated by tightening torque needs to be increased within the elastic limit of the screw. However, additional tensile forces can produce the plastic deformation of abutment screw when functional loads are superimposed on preload stresses, and they can elicit loosening or fracture of the abutment screw. Therefore, it is necessary to find the optimum tightening torque that maximizes a fatigue life and simultaneously offer a reasonable degree of protection against loosening. PURPOSE: The purpose of this study was to present the influence of tightening torque on the implant-abutment screw joint stability with the 3 dimensional finite element analysis. MATERIAL AND METHODS: In this study, the finite element model of the implant system with external butt joint connection was designed and verified by comparison with additional theoretical and experimental results. Four different amount of tightening torques (10, 20, 30 and 40 Ncm) and the external loading (250 N, 30degrees C) were applied to the model, and the equivalent stress distributions and the gap distances were calculated according to each tightening torque and the result was analyzed. RESULTS: Within the limitation of this study, the following results were drawn; 1) There was the proportional relation between the tightening torque and the preload. 2) In case of applying only the tightening torque, the maximum stress was found at the screw neck. 3) The maximum stress was also shown at the screw neck under the external loading condition. However in case of applying 10 Ncm tightening torque, it was found at the undersurface of the screw head. 4) The joint opening was observed under the external loading in case of applying 10 Ncm and 20 Ncm of tightening torque. 5) When the tightening torque was applied at 40 Ncm, under the external loading the maximum stress exceeded the allowable stress value of the titanium alloy. CONCLUSION: Implant abutment screw must have a proper tightening torque that will be able to maintain joint stability of fixture and abutment.
Alloys ; Dental Implants ; Fatigue ; Finite Element Analysis ; Head ; Joints ; Neck ; Plastics ; Titanium ; Torque