Physical stability of arginine-glycine-aspartic acid peptide coated on anodized implants after installation

PURPOSE: The aim of this study was to evaluate the stability of arginine-glycine-aspartic acid (RGD) peptide coatings on implants by measuring the amount of peptide remaining after installation. MATERIALS AND METHODS: Fluorescent isothiocyanate (FITC)-fixed RGD peptide was coated onto anodized titanium implants (width 4 mm, length 10 mm) using a physical adsorption method (P) or a chemical grafting method (C). Solid Rigid Polyurethane Foam (SRPF) was classified as either hard bone (H) or soft bone (S) according to its density. Two pieces of artificial bone were fixed in a customized jig, and coated implants were installed at the center of the boundary between two pieces of artificial bone. The test groups were classified as: P-H, P-S, C-H, or C-S. After each installation, implants were removed from the SRPF, and the residual amounts and rates of RGD peptide in implants were measured by fluorescence spectrometry. The Kruskal-Wallis test was used for the statistical analysis (alpha=0.05). RESULTS: Peptide-coating was identified by fluorescence microscopy and XPS. Total coating amount was higher for physical adsorption than chemical grafting. The residual rate of peptide was significantly larger in the P-S group than in the other three groups (P<.05). CONCLUSION: The result of this study suggests that coating doses depend on coating method. Residual amounts of RGD peptide were greater for the physical adsorption method than the chemical grafting method.

Marginal and internal fitness of three-unit zirconia cores fabricated using several CAD/CAM systems / 대한치과보철학회지

PURPOSE: This study was aimed to compare the margin and internal fitness of 3-unit zirconia bridge cores fabricated by several CAD/CAM systems using replica technique. MATERIALS AND METHODS: Three unit-bridge models in which upper canine and upper second premolar were used as abutments and upper first premolar was missed, were fabricated. Fourty models were classified into 4 groups (Cerasys(R) (Group C), Dentaim(R) (Group D), KaVo Everest(R) (Group K), Lava(TM)(Group L)), and zirconia cores were fabricated by each company. Sixteen points were measured on each abutment by replica technique. Statistical analysis was accomplished with two way ANOVA and Dunnett T3 (alpha=.05). RESULTS: In most systems, there was a larger gap on inter margin than outer margin. In the Group K, overall fitness was excellent, but the incisal gap was very large. In the Group C, marginal gap was significantly larger than Group K, but overall internal gap was uniform (P<.05). The axial gap was under 100 microm in all system. The difference between internal and external gap was small on Group L and C. However, internal gap was significantly larger than external gap in Group D (P<.05). The fitness of canine was better than second premolar among abutments (P<.05). CONCLUSION: The marginal and internal gap was within the clinically allowed range in all of the three systems. There was a larger gap on second premolar than canine on internal and marginal surface. In most systems, there was a larger gap on occlusal surface than axial surface.

A Clinical Review of Acute Poisonings in Geriatric Patients from Rural Gangwon Province

BACKGROUND: Recently, there has been an increase in acute poisonings in the elderly, which may be associated with attempts at suicide. The purpose of this study was to compare and analyze the clinical aspects and outcomes of acute poisonings in aged individuals with those of younger individuals. METHODS: We performed a retrospective analysis of 207 patients seen in the emergency department (ED) with acute poisoning from January 2009 to December 2010. Two groups were created, >65 years and 65 group and 0.3% in the 65 years than in those <65 years. As motive for suicide, health problem was cited more often in the older group (p=0.000). The older group had fewer interviews with psychiatrists and were more often diagnosed with depressive disorder (p=0.010, p=0.041, respectively). PSS and mortality were higher in the older group (p=0.002, p=0.010, respectively). CONCLUSION: A better understanding for the cause of poisonings and the poisonous substance used in the aged population is needed. And because of the more serious effects of acute poisonings to the elderly patient, they should readily receive regular comprehensive care including psychiatric care.

Three-dimensional finite element analysis on stress distribution of the mandibular implant-supported cantilever prostheses depending on the designs / 대한치과보철학회지

STATEMENT OF PROBLEM: The position and length of cantilever influence on the stress distribution of implants, superstructure and bone. In edentulous mandible, implant-supported cantilever prostheses that based 4 or 6 implants between mental foramens has been attempted. Excessive bite force loaded at cantilever prosthesis causes bone resorption and breakage of superstructure prosthesis around posterior implants. To complement the cantilever length of conventional prosthesis, In 1992, (McCartney) introduced "cantilever - rest - implant" and Malo reported "All-on-Four" in 2003. PURPOSE: Analyze and compare the stress distribution of conventional cantilever prostheses with rest implant and Allon-Four(TM) implant prostheses. MATERIAL AND METHOD: The external loads (300 N vertically, 75 N horizontally) are applied to first molar area. The stress value, stress distribution and aspect of stress dispersion are analyzed by three-dimensional finite element analysis program, ANSYS ver. 10.0. RESULTS: 1. The rest implant and "All-on-Four" implant system are superior to conventional cantilever prostheses to reduce stress on the bone and the superstructure around implants. 2. The rest implant was of the greatest advantage to stress distribution on bone, implant and superstructure. 3. With same number of implants, distally tilted implants are preferred to conventional cantilever prostheses for reducing the length of cantilever.

Shear bond strengths of composite resin to porcelains among porcelain repair systems / 대한치과보철학회지

PURPOSE: This in vitro study evaluated shear bond strengths of surface treatment porcelains with four porcelain repair systems simulating intraoral bonding of composite resin to feldspathic porcelain or pressable porcelain. MATERIAL AND METHODS: Eighty Porcelain disks were prepared. Group A: forty disk specimens were fabricated with Feldspathic Porcelain(Omega(R)900, Vident, Menlo Park, CA, USA). Group B: forty disk specimens were fabricated with Pressable Porcelain(IPS Empress 2 ingot, Ivoclar-Vivadent, Schaan, Liechtenstein, Germany). Each groups was divided into 4 subgroups and composite resin cylinders were bonded to specimen with one of the following four systems: Clearfil Porcelain Bond(L. Morita, Tustin, CA, USA), Ulradent Porcelain Etch.(Ultradent, Salt Lake City, UT, USA), Porcelain Liner-M(Sun Medical Co., Kyoto, Japan), Cimara Kit(Voco, Germany). After surface conditioning with one of the four porcelain repair systems, substrate surfaces of the specimen were examined microscopically(SEM). Shear bond strengths of specimens for each subgroup were determined with a universal testing machine (5mm/min crosshead speed) after storing them in distilled water at 37+/-1 degrees C for 24 hours. Stress at failure was measured in MPa, and mode of failure was recorded. Differences among four repair systems were analyzed with two way ANOVA and Duncan test at the 95% significance level. RESULTS: In the scanning electron photomicrograph of the treated porcelain surface, hydrofluoric acid etched group appeared the highest roughness. The shear bond strength of the phosphoric acid etched group was not significantly(p>0.05) different between feldspathic porcelain and pressable porcelain. But in no treatment and roughened with a bur group, the shear bond strength of the feldspathic porcelain was significantly higher than that of the pressable porcelain. In hydrofluoric acid etched group, the shear bond strength of the pressable porcelain was significantly higher(p0.05). However in the other groups, there were significant differences in shear bond strengths between feldspathic porcelain and pressable porcelain(p<0.05).

In vitro study on the adherence and penetration of candida albicans into denture soft lining materials / 대한치과보철학회지

Purpose: Colonization of denture soft lining materials by Candida albicans can result in clinical problem, and deterioration of the materials. This study aimed to compare the retention and penetration of C. albicans into four denture soft lining materials commonly used. Materials and methods: Four denture soft lining materials(Coe-comfort., Coe-soft., GC soft liner., and Tissue conditioner.) discs were prepared to glass slide and dental stone. Adherence of yeast to surfaces was monitored after one hour incubation of standardized washed cell suspension with test disc surfaces. Adherent cells stained with acridine orange were counted fluorescence microscopy. Penetration of yeast into materials bonded with acrylic resin after 1, 2, 3, 4, 5, 6 and 7 days incubation was observed through sections stained using acridine orange and estimated to quantitative analysis using radioisotope. Results: There was statistical significance in cell numbers between smooth and rough surfaces(p<0.05). Higher numbers of cells were observed on rough surfaces. There was statistical significance in adherent cell numbers into smooth and rough surfaces individually(p<0.05). According to the increase of incubation periods, the cells penetrated into denture soft lining materials were shown to increase. The differences among all kinds of soft liner were statistically significant(p<0.05),and the largest number of cells penetrated into soft liners was observed in the Coe-soft. Conclusion: Initial adherence and penetration of yeast into denture soft lining materials has been influenced by surface roughness and chemical composition of them. The selection of appropriate materials and their fabrication may promote clinical performance.

Clinical features of tsutsugamushi disease in Chuncheon / 대한내과학회지

BACKGROUND: Tsutsugamushi disease is an acute febrile disease in Korea. Some patients with tsutsugamushi disease have severe illness, which needs care in intensive care unit, and may die due to the disease. We analyzed the cases with tsutsugamushi disease who lived in Chuncheon and neighboring communities to find out clinical manifestations, laboratory findings especially in severe cases. METHODS: We reviewed the clinical records of the 81 cases who were diagnosed as tsutsugamushi in Chuncheon Sacred Heart Hospital from April, 1997 to December, 2002. We analyzed the clinical and laboratory findings of the 81 cases, and the treatment results of 79 cases who recieved the treatment in this hospital. We also compared the characteristics of the patients between admission to general ward and intensive care unit (ICU). RESULTS: Seventy three cases developed the disease in autumn. Seventy cases had fever. 58 cases had eschar in their bodies. With the doxycycline treatment, forty five cases subsided the fever within 48 hours, but in 13 cases, fever continued after 5 days of treatment. Twenty five cases were admitted to ICU, 8 cases among them were treated with ventilator, 3 cases died due to the multi-organ failure. When we compared the clinical characteristics of the patients admitted to ICU with those to general wards, leukocyte count, the level of BUN and creatinine were higher, the albumin level was lower in ICU patients than those of general ward patients. CONCLUSION: Tsutsugamushi disease can progress to severe disease, and be fatal to the patients. So it is necessary to diagnose early and treat carefully. We suggest that leukocyte count, BUN, creatinine, or albumin can be used to predict the prognosis.

Influence of individual tooth tray on the teeth with undercut in impression taking / 대한치과보철학회지

PROBLEM: The several studies were reported to the effects of individual tooth tray with the parallel tooth, but not reported to the effect of individual tooth tray with severe undercut in impression making. PURPOSE: The purpose of this study is to examine the effect of individual tooth tray; 1) the accuracy of impression in in terms of distance. 2) reproducibility of pocket. MATERIAL AND METHODS: In this study, a metal model with 3 teeth including tooth prepared 30-degree undercut and gingival crevice of the depth 5mm, width 0.4mm was cast. Impressions of the metal model were taken in 5 times used 4 kinds of impression materials with individual tooth tray and another impression taking were made with conventional method without individual tooth, used same materials, procedure. The stone models were made. Distances between abutments were measured with a Micromeasurescoup-mm. RESULT: The following results were obtained; 1. In the comparison of inter-abutment distance between parallel tooth without individual tooth tray, 4elastomeric materials have not significant difference to the metal model(p>0.05). 2. In the comparisonof inter-abutment distance with undercut tooth without individual tooth tray, 4elastomeric materials have a significant difference to the metal model(p0.05). 4. It is not true that the pressure of impression material with individual tooth tray increased to gingival sulcus. CONCLUSION: By the results, I knew the fact that individual tooth tray was useful impression method on the teeth with severe undercut for the dimensional stability. Also, I could not confirm the fact that individual tooth tray would increase the penetrating pressure into cervice.

Two cases of successful management of paraquat poisoning with pulmonary fibrosis / 대한내과학회지

Paraquat, a very potent herbicide, has produced many fatalities through indiscriminate usage and suicides. It is known that with ingestion of more than one mouthful of 20% paraquat, death usually occurs by pulmonary fibrosis. We experienced two cases of successful outcome in patients with paraquat poisoning complicated with pulmonary fibrosis through active, intensive treatment from the early phase after ingestion. They swallowed one to two mouthfuls of the 20% commercial paraquat, and received hemoperfusion within 2-3 hours after ingestion. Then, combination therapy with steroid, vitamin C, D-penicillamine, allopurinol, colchicine was administered from the early phase. They showed moderate to severe hypoxemia and pulmonary fibrosis on chest HRCT during hospital course, but recovered from hypoxemia and remained very well on follow up over 3 months and 12 months after ingestion, respectively. We report these cases with literature review on treatment and prognosis of paraquat poisoning.

Two cases of successful management of paraquat poisoning with pulmonary fibrosis / 대한내과학회지

Paraquat, a very potent herbicide, has produced many fatalities through indiscriminate usage and suicides. It is known that with ingestion of more than one mouthful of 20% paraquat, death usually occurs by pulmonary fibrosis. We experienced two cases of successful outcome in patients with paraquat poisoning complicated with pulmonary fibrosis through active, intensive treatment from the early phase after ingestion. They swallowed one to two mouthfuls of the 20% commercial paraquat, and received hemoperfusion within 2-3 hours after ingestion. Then, combination therapy with steroid, vitamin C, D-penicillamine, allopurinol, colchicine was administered from the early phase. They showed moderate to severe hypoxemia and pulmonary fibrosis on chest HRCT during hospital course, but recovered from hypoxemia and remained very well on follow up over 3 months and 12 months after ingestion, respectively. We report these cases with literature review on treatment and prognosis of paraquat poisoning.

A case of disseminated intravascular coagulation after tooth extraction in abdominal aortic aneurysm / 대한내과학회지

Disseminated intravascular coagulation (DIC) is the result of a severe underlying disorder that initiates massive activation of the coagulation system. We report an unusual case of 79-year-old man who developed DIC after tooth extraction in abdominal aortic aneurysm. He was referred to our hospital because of persistent bleeding after tooth extraction. Physical examination indicated a pulsating mass in abdomen. Abdominal computerized tomography (CT) scan revealed 70 mm diameter aneurysm of the abdominal aorta, extending from the renal infrahilar level to the common iliac artery, and his coagulation profile showed the features of DIC by revealing thrombocytopenia, hypofibrinogenemia, and increased level of fibrinogen degradation product (FDP). After he had received blood component therapy including fresh frozen plasma and continuous intravenous heparin infusion (4,800 U/day), the bleeding diathesis and coagulopathy improved. He refused to have definitive surgery for the aneurysm.

Effects of cytochrome P450 2E1 polymorphism on hepatic injury in patients with alcoholic liver cirrhosis / 대한내과학회지

BACKGROUND: There is an individual variation in the hepatic injuries following alcohol abuse, which may be partly caused by the diverse activities of enzymes participating in the degradation of alcohol. Polymorphism of cytochrome P450 2E1 (CYP2E1) gene has been reported to affect the degradating activity of the enzyme, which may be eventually associated with the severity of alcoholic liver disease. In this study we were to evaluate the effects of genetic polymorphism of CYP2E1 on hepatocellular injury or fibrosis. METHODS: We analyzed the relationship of CYP2E1 genotypes to the biochemical and clinical characteristics as well as TGFbeta1 expressions in a total of 33 patients (M:F=32:1) with advanced alcoholic liver cirrhosis. CYP2E1 genotypes were determined by RFLP using RsaI and PstI. The amounts of serum TGFbeta1 were measured by ELISA (TGFbetta1 ELISA system, Promega, USA). RESULTS: Out of 33, 23 (70%) had the CYP2E1 of genotype A and all of the remaining 10 (30%) were type B; there was no one who had type C. The serum albumin levels of patients with type A of CYP2E1 gene were lower than those with type B (p=0.01); the Child-Pugh scores were also higher in patients with type A than B (p=0.03). However, there was no difference between the two groups in the serum AST, ALT, gamma-GTP and bilirubin levels. The patients expressed similar amount of serum TGFbetta1 regardless of their CYP2E1 genotypes. CONCLUSION: Our data indicates that the most common genotype of CYP2E1 is type A (70%) in patients with advanced alcoholic liver cirrhosis in Korea. It is also suggested that patients with enotype A of CYP2E1 may be associated with more advanced alcoholic liver cirrhosis compared to those with type B.

Hemoperfusion and continuous veno-venous hemofiltration for treatment of paraquat poisoning / 대한내과학회지

BACKGROUND: In Korea, paraquat accounts for most of fatal poisoning with 500 or more deaths per year. It has been known that patients who ingested more than 1/2 mouthful of 20% concentrate paraquat usually die of multiorgan failure and pulmonary fibrosis. But the effect of charcoal hemoperfusion which can enhance elimination of paraquat remains controversial. Because acute paraquat poisoning is also characterized by multiorgan failure including kidney and marked rebound in plasma paraquat level after hemoperfusion, Continuous veon-venous hemofiltration(CVVH) may have theoretical benefits in the treatment of paraquat poisoning. So we evaluated the effect of early charcoal hemoperfusion and prophylactic CVVH after hemoperfusion in patients with paraquat poisoning. METHODS: There were 80 patients with paraquat poisoning admitted within 24 hours after ingestion (August 1996 - March 1998). All of them were treated with hemoperfusion (duration of hemoperfusion, 6.4+/-3.0 hours) within 24 hours of ingestion. The amount of ingestion was 2.1+/-1.0 mouthful (as 20% concentrate) and 78 (98%) were urine sodium dithionite test positive which is a poor prognosis factor. Forty-four patients received hemoperfusion only and 36 were followed by CVVH (duration, 50.4+/-20.9 hours; ultrafiltration volume, 33.8+/-3.9 L/day) after hemoperfusion. RESULTS: There was no difference between the hemoperfusion group and hemoperfusion+CVVH group in age, sex, initial serum creatinine, arterial oxygen saturation, severity of poisoning (as assessed by serum paraquat level determined by HPLC and amount of ingestion), or in the time elapsed from ingestion to the beginning of hemoperfusion. The total mortality was 65% (52/80) with no difference between the hemoperfusion group (64%, 28/44) and hemoperfusion+CVVH group (67%, 24/36). The mortality according to amount of ingestion was as follows: or = 3 mouthful, 82% (27/33); unknown, 60% (6/10). CONCLUSION: Early hemoperfusion can be effective in reducing mortality in patients who ingest less than 2 mouthful. Even though prophylactic CVVH after hemoperfusion has no additional benefit in reducing mortality in paraquat poisoning, it prolonged the time to death after ingestion.