• Title/Summary/Keyword: 조사방법

Search Result 23,114, Processing Time 0.055 seconds

The Influences of Maintenance Hemodialysis on Sleep Architecture and Sleep Apnea in the Patients with Chronic Renal Failure (만성신부전 환자에서 혈액투석 유지요법이 수면구조 및 수면 무호흡에 미치는 영향)

  • Park, Yong-Geun;Lee, Sang-Haak;Choi, Young-Mee;Ahn, Seok-Joo;Kwon, Soon-Seog;Kim, Young-Kyoon;Kim, Kwan-Hyoung;Song, Jeong-Sup;Park, Sung-Hak;Moon, Hwa-Sik
    • Tuberculosis and Respiratory Diseases
    • /
    • v.47 no.6
    • /
    • pp.824-835
    • /
    • 1999
  • Background: Sleep-related breathing disorders are commonly found in patients with chronic renal failure and particularly, sleep apnea may have an influence on the long-term mortality rates in these patients. Maintenance hemodialysis is the mainstay of medical measures for correcting the metabolic derangements of chronic renal failure but it is uncertain whether it may alleviate sleep disorders including sleep apnea. Methods: Forty seven patients on maintenance hemodialysis were surveyed with the sleep questionnaire about their clinical symptoms related to sleep disorders. Among them, 15 patients underwent the polysomnography and their blood levels of urea nitrogen, creatinine, electrolytes and the arterial blood gases in the nights before and following hemodialysis were measured. Results: Forty(85.1%) of the 47 patients complained of the symptoms associated with sleep-wake cycle disturbances, 55.3% experienced snoring and 27.7% reported witnessed apneas. The duration of REM sleep increased significantly in the nights after hemodialysis compared to the nights without hemodialysis(p<0.05) and the percentage of total sleep time comprising NREM sleep decreased significantly in the nights following hemodialysis compared to the nights before hemodialysis(p<0.05). The percentage of total sleep time consisting of the stage 1 and 2 NREM sleep showed the trend for a decrease in the nights after hemodialysis(p=0.051), while the percentage of total sleep time comprising the stage 3 and 4 NREM sleep did not change between nights. The obstructive sleep apnea was more predominant type than the central one in both nights and there were no differences in the apnea index and the apnea-hypopnea index between the nights. The decrease in the blood level of urea nitrogen, creatinine, potassium and phosphorus was observed after hemodialysis(p<0.05), but the differences of parameters measured during polysomnography between the nights did not correlate with the changes of biochemical factors obtained on the two nights. Arterial blood gas analysis showed that pH was significantly greater in the nights after hemodialysis than in the nights before hemodialysis(p<0.05), but there were no correlations between the parameters examined during polysomnography and the parameters of arterial blood gas analysis(p<0.05). Conclusion: These results suggest that chronic renal failure is an important systemic disorder which is strongly associated with sleep disorders. Maintenance hemodialysis, although it is a widely accepted measure to treat chronic renal failure, did not significantly modulate the sleep architecture and the severity of sleep apnea. Thus, taking the patients with chronic renal failure into account, it is advisable to try not only to find a substantial way for correcting metabolic derangements but also to consider the institution of more effective treatments for sleep disorders.

  • PDF

Pulmonary Mycoses in Immunocompromised Hosts (면역기능저하 환자에서 폐진균증에 대한 임상적 고찰)

  • Suh, Gee-Young;Park, Sang-Joon;Kang, Kyeong-Woo;Koh, Young-Min;Kim, Tae-Sung;Chung, Man-Pyo;Kim, Ho-Joong;Han, Jong-Ho;Choi, Dong-Chull;Song, Jae-Hoon;Kwon, O-Jung;Rhee, Chong-H.
    • Tuberculosis and Respiratory Diseases
    • /
    • v.45 no.6
    • /
    • pp.1199-1213
    • /
    • 1998
  • Background : The number of immunocompromised hosts has been increasing steadily and a new pulmonary infiltrate in these patients is a potentially lethal condition which needs rapid diagnosis and treatment. In this study we sought to examine the clinical manifestations, radiologic findings, and therapeutic outcomes of pulmonary mycoses presenting as a new pulmonary infiltrate in immunocompromised hosts. Method : All cases presenting as a new pulmonary infiltrate in immunocompromised hosts and confirmed to be pulmonary mycoses by pathologic examination or by positive culture from a sterile site between October of 1996 and April of 1998 were included in the study and their chart and radiologic findings were retrospectively reviewed. Results : In all, 14 cases of pulmonary mycoses from 13 patients(male : female ratio = 8 : 5, median age 47 yr) were found. Twelve cases were diagnosed as aspergillosis while two were diagnosed as mucormycosis. Major risk factors for fungal infections were chemotherapy for hematologic malignancy(10 cases) and organ transplant recipients(4 cases). Three cases were receiving empirical amphotericin B at the time of appearance of new lung infiltrates. Cases in the hematologic malignancy group had more prominent symptoms : fever(9/10), cough(6/10), sputum(5/10), dyspnea(4/10), chest pain(5/10). Patients in the organ transplant group had minimal symptoms(p<0.05). On simple chest films, all of the cases presented as single or multiple nodules(6/14) or consolidations(8/14). High resolution computed tomograph showed peri-lesional ground glass opacities(14/14), pleural effusions(5/14), and cavitary changes(7/14). Definitive diagnostic methods were as follows : 10 cases underwent minithoracotomy, 2 underwent video-assisted thoracoscopic surgery, 1 underwent percutaneous needle aspiration and 1 case was diagnosed by culture of abscess fluid. All cases received treatment with amphotericin B with 1 case each being treated with liposomal amphotericin B and itraconazole due to renal toxicity. Lung lesion improved in 12 of 14 patient but 4 patients died before completing therapy. Conclusion : When a new lung infiltrate develops presenting either as a nodule or consolidation in a neutropenic patient with hematologic malignancy or in a transplant recipient, you should always consider pulmonary mycoses as one of the differential diagnosis. By performing aggressive work up and early treatment, we may improve prognosis of these patients.

  • PDF

Requirement and Perception of Parents on the Subject of Home Economics in Middle School (중학교 가정교과에 대한 학부모의 인식 및 요구도)

  • Shin Hyo-Shick;Park Mi-Soog
    • Journal of Korean Home Economics Education Association
    • /
    • v.18 no.3 s.41
    • /
    • pp.1-22
    • /
    • 2006
  • The purpose of this study is that I should look for a desirous directions about home economics by studying the requirements and perception of the high school parents who have finished the course of home economics. It was about 600 parents whom I have searched Seoul-Pusan, Ganwon. Ghynggi province, Choongcheong-Gyungsang province, Cheonla and Jeju province of 600, I chose only 560 as apparently suitable research. The questions include 61 requirements about home economics and one which we never fail to keep among the contents, whenever possible and one about the perception of home economics aims 11 about the perception of home economics courses and management. The collections were analyzed frequency, percent, mean. standard deviation t-test by using SAS program. The followings is the summary result of studying of it. 1. All the boys and girls learning together about the Idea of healthy lives and desirous human formulation and knowledge together are higher. 2. Among the teaching purposes of home economics, the item of the scientific principle and knowledge for improvements of home life shows 15.7% below average value. 3. The recognition degree about the quality of home economics is highly related with the real life, and about the system. we recognize lacking in periods and contents of home economics field and about guiding content, accomplishment and application qualities are higher regardless of sex. 4. The important term which we should emphasize in the subject of home economics is family part. 5. Among the needs of home economic requirement in freshman, in the middle unit, their growth and development are higher than anything else, representing 4.11, and by contrast the basic principle and actuality is 3.70, which is lowest among them. 6. In the case of second grade requirement of home economics content for parents in the middle unit young man and consuming life is 4.09 highest. 7. In the case of 3rd grade requirement of economics contents in the middle unit the choice of coming direction and job ethics is highest 4.16, and preparing meals and evaluation is lowest 3.50.

  • PDF

Hypertension Management Status in Rural Hypertensives (농촌지역(農村地域) 고혈압환자(高血壓患者)의 고혈압(高血壓) 관리행태(管理行態))

  • Kim, Hyun-Sook;Kam, Sin;Kim, Jong-Yeon;Park, Ki-Soo;Lee, Kyeong-Soo
    • Journal of agricultural medicine and community health
    • /
    • v.28 no.1
    • /
    • pp.93-106
    • /
    • 2003
  • Objectives: This study was conducted to investigate the treatment status and its related factors of the rural hypertensives. Methods: A questionnaire survey was performed to 618 rural hypertensives during September, 2002. Results: The proportion of those who were compliant to the antihypertensive medication was 68.9%. The compliance rate to the antihypertensive medication was significantly related with sex and economic status(p<0.05). That is, if they were female, higher economic level, the regular antihypertensive medication rate was higher. The regular antihypertensive medication rate was higher when they had higher knowledge for hypertension, higher severity for hypertension of him or her(p<0.01). And the compliance rate to the antihypertensive medication was significantly related with hypertensives' own explanatory model for hypertension(p<0.01). The rate of drug use except antihypertensives was 12.5%. The rate of drug use except antihypertensives was higher when they experienced side effects of antihypertensive drug and when they had irregular medication for antihypertensive drug(p<0.01). The rate of medical equipment use was 18.9%. The utilization rate of medical equipment such as jade mat, germanium material was significantly related with age, experience of side effects of antihypertensive drug, medication status for antihypertensive drug(p<0.05). The rate of folk therapy use was 16.2%. The rate of folk therapy use was higher when they had no family, when they had knowledge about hypertension on the average, when they had hypertension over 10 years(p<0.05), and when they experienced side effects of antihypertensive drug and when they had irregular medication for antihypertensive drug(p<0.01). The rates of drug use except antihypertensives, medical equipment use, and folk therapy were significantly related with hypertensives' own explanatory model for hypertension(p<0.05). Conclusions: On consideration of above findings, it would be essential to provide knowledge about hypertension and its treatment, and severity of hypertension complications through health education.

  • PDF

Genetic Variants of the Blood Proteins and Enzymes in Beef Cattle (육우의 혈액단백질 및 효소의 유전적 변이체)

  • Sang, Byung Chan;Ryoo, Seung Heue;Sang, Byung Don
    • Korean Journal of Agricultural Science
    • /
    • v.22 no.1
    • /
    • pp.69-81
    • /
    • 1995
  • This study was conducted to examine the genetic variants of the blood proteins and enzymes in beef cattle breeds, Hereford, Angus and Sharolais reared at the Daekwanryuong Branch of the National Livestock Research Institute. Genetic polymorphisms of transferrin(Tf), post-transferrin2(pTf-2), albumin(Alb), post-albumin (pAlb), ceruloplasmin(Cp), amylase-I(Am-I) and hemoglobin(Hb) in blood were analyzed by the methods of PAGE(polyacrylamide gel electrophoresis) and STAGE(starch gel electrophoresis). The results obtained from this study were summarized as follows: 1. Tf and pTf-2 locus assumed to be controlled by codominant alleles, A. $D_1$, $D_2$ and E allele for Tf, F and S allele for pTf-2. In genotype frequencies, 25% and 90% for Tf $D_1D_2$ and pTf-2 SS in Hereford, 25% and 100% for Tf $AD_1$ and pTf-2 FF in Angus, 50% for Tf $D_1D_1$ and pTf-2 FS in Sharolais were found to have the highest frequency, respectively. In gene frequencies, 0.400 and 0.900 for Tf E and pTf-2 S allele in Hereford, 0.678 and 0.607 for Tf $D_1$ and pTf-2S in Sharolais were appeared to have the highest frequency. 2. Alb and pAlb locus assumed to be controlled by codominant alleles, only A allele for Alb, F and S allele for pAlb. In genotype frequencies, 70% for pAlb SS in Hereford, 90% for pAlb FF in Angus and 57.15% for pAlb SS in Sharolais were found to have the highest frequency. In gene frequencies, 0.825 and 0.750 for pAlb S in Hereford and Charolais, 0.900 for pAlb F in Angus were found to have the highest frequency. 3. Cp and Am-I locus appeared to be controlled by two alleles, F and S allele for Cp, B and C allele for Am-I. In genotype frequencies, 100% and 65% for Cp FF and Am-I BB in Hereford, 45% and 85% for Cp FF, and Am-I CC in Angus, 50% and 64.29% for Cp FF and Am-I BC in Sharolais were found to have the highest frequency. Gene frequencies were 1,000, 0.600 and 0.750 for Cp F in Herehord, Angus and Sharolais, 0.800, 0.875 and 0.680 for Am-I B, C and C allele in Hereford, Angus and sharolais, respectively. 4. Hb locus assumed to be controlled by codominant alleles, only A allele in Hereford and Angus, A and B allele in Sharolais. Genotype frequencies were 57.14% and 42.86% for Hb AA and AB in Sharolais, and gene frequencies were 0.785 and 0.215 for Hb A and B in Sharolais.

  • PDF

The Prognostic Value of the First Day and Daily Updated Scores of the APACHE III System in Sepsis (패혈증환자에서 APACHE III Scoring System의 예후적 가치)

  • Lim, Chae-Man;Lee, Jae-Kyun;Lee, Sung-Soon;Koh, Youn-Suck;Kim, Woo-Sung;Kim, Dong-Soon;Kim, Won-Dong;Park, Pyung-Hwan;Choi, Jong-Moo
    • Tuberculosis and Respiratory Diseases
    • /
    • v.42 no.6
    • /
    • pp.871-877
    • /
    • 1995
  • Background: The index which could predict the prognosis of critically ill patients is needed to find out high risk patients and to individualize their treatment. The APACHE III scoring system was established in 1991, but there has been only a few studies concerning its prognostic value. We wanted to know whether the APACHE III scores have prognostic value in discriminating survivors from nonsurvivors in sepsis. Methods: In 48 patients meeting the Bones criteria for sepsis, we retrospectively surveyed the day 1(D1), day 2(D2) and day 3(D3) scores of patients who were admitted to intensive care unit. The scores of the sepsis survivors and nonsurvivors were compared in respect to the D1 score, and also in respect to the changes of the updated D2 and D3 scores. Results: 1) Of the 48 sepsis patients, 21(43.5%) survived and 27(56.5%) died. The nonsurvivors were older($62.7{\pm}12.6$ vs $51.1{\pm}18.1$ yrs), presented with lower mean arterial pressure($56.9{\pm}26.2$ vs $67.7{\pm}14.2\;mmHg$) and showed greater number of multisystem organ failure($1.2{\pm}0.8$ vs $0.2{\pm}0.4$) than the survivors(p<0.05, respectively). There were no significant differences in sex and initial body temperature between the two groups. 2) The D1 score was lower in the survivors (n=21) than in the nonsurvivors ($44.1{\pm}14.6$, $78.5{\pm}18.6$, p=0.0001). The D2 and D3 scores significantly decreased in the survivors (D1 vs D2, $44.1{\pm}14.6$ : $37.9{\pm}15.0$, p=0.035; D2 vs D3, $37.9{\pm}15.0$ : $30.1{\pm}9.3$, p=0.0001) but showed a tendency to increase in the nonsurvivors (D1 vs D2 (n=21), $78.5{\pm}18.6$ : $81.3{\pm}23.0$, p=0.1337; D2 vs D3 (n=11), $68.2{\pm}19.3$ : $75.3{\pm}18.8$, p=0.0078). 3) The D1 scores of 12 survivors and 6 nonsurvivors were in the same range of 42~67 (mean D1 score, $53.8{\pm}10.0$ in the survivors, $55.3{\pm}10.3$ in the nonsurvivors). The age, sex, initial body temperature, and mean arterial pressure were not different between the two groups. In this group, however, D2 and D3 was significantly decreased in the survivors(D1 vs D2, $53.3{\pm}10.0$ : $43.6{\pm}16.4$, p=0.0278; D2 vs D3, $43.6{\pm}16.4$ : $31.2{\pm}10.3$, p=0.0005), but showed a tendency to increase in the nonsurvivors(D1 vs D2 (n=6), $55.3{\pm}10.3:66.7{\pm}13.9$, p=0.1562; D2 vs D3 (n=4), $64.0{\pm}16.4:74.3{\pm}18.6$, p=0.1250). Among the individual items of the first day APACHE III score, only the score of respiratory rate was capable of discriminating the nonsurvivors from the survivors ($5.5{\pm}2.9$ vs $1.9{\pm}3.7$, p=0.046) in this group. Conclusion: In sepsis, nonsurvivors had higher first day APACHE III score and their updated scores on the following days failed to decline but showed a tendency to increase. Survivors, on the other hand, had lower first day score and showed decline in the updated APACHE scores. These results suggest that the first day and daily updated APACHE III scores are useful in predicting the outcome and assessing the response to management in patients with sepsis.

  • PDF

Chest CT findings and Clinical features in Mediastinal Tuberculous Lymphadenitis (종격동 결핵성 임파선염의 흉부전산화 단층촬영 소견과 임상 양상에 대한고찰)

  • Lee, Young-Sil;Kim, Kyeong-Ho;Kim, Chang-Sun;Cho, Dong-Ill;Rhu, Nam-Soo
    • Tuberculosis and Respiratory Diseases
    • /
    • v.42 no.4
    • /
    • pp.481-491
    • /
    • 1995
  • Background: Recently there has been a trend of an increasing incidence of mediastinal tuberculous lymphadenitis(MTL) in adults. MTL often cause bronchial stenosis or esophago-mediastinal fistula. In spite of effective treatment, it is difficult to cure. Moreover, relapse frequently occurs. Authors analyzed chest CT findings and clinical features of 29 cases with MTL Methods: 29 cases with MTL were retrospectively studied with the clinical and radiologic features from April 1990 to March 1995 Results: 1) A total of 29 cases were studied. 12 cases were male and 17 cases were female. The male to female ratio was 1:1.4 Mean age was 29 years old. The 3rd decade(45%) was the most prevalent age group 2) The most common presenting symptoms and signs were palpable neck masses(62%) followed by cough(59%) and sputum(38%) 3) Except in one case of MTL, all patients had coexisting pulmonary tuberculosis, cervical tuberculous lymphadenitis, endobronchial tuberculosis and tuberculous pleurisy. Among the coexisting tuberculous diseases, Pulmonary tuberculosis was the most common(76%) 4) On simple chest X-ray, mediastinal enlargement was noted in 21 cases(72%), but it was not noted in 8 cases(28%). The most frequently involving site was the paratracheal node in 16 cases(72%). Rt side predominence(73%) was noted 5) Patterns of node appearance on a postcontrast CT scan were classified into 3 types. There were 19 cases(30%) of the Homogenous type, 30 cases(47%) of the Central low density type and 15 cases(23%) of the Peripheral fat obliteration type. The most common type was the central low density type. The most common lymph node size was 1~2 cm(88%) 6) The most frequently involved site was the paratracheal node in 26 cases(89%) by chest CT. Rt side(63%) was predominant 7) 9 cases(43%) had complete therapy and most common treatment duration was 13 - 18 months. 12 cases(57%) had incomplete continuing antituberculous medication and half of the cases had been treated above 19 months. Conclusion: Chest CT findings of MTL showed central low density area and peripheral rim enhancement, so this characteristic findings could differentiate it from other mediastinal diseases and help a diagnosis of tuberculosis. In spite of effective antituberculous medication, it is difficult to cure. Moreover, relapse frequently occurs. Further studies will be needed of the clinical features and the treatment of MTL.

  • PDF

Human Parathyroid Hormone-Related Peptide Measurement in the Lung Cancer Patients (폐암환자에서 인체 부갑상선 호르몬 관련 단백에 대한 연구)

  • Chang, Joon;Kim, Se-Kyu;Lim, Sung-Kil;Lee, Hong-Lyeol;Kim, Sung-Kyu;Lee, Won-Young
    • Tuberculosis and Respiratory Diseases
    • /
    • v.42 no.6
    • /
    • pp.855-861
    • /
    • 1995
  • Background: Parathyroid hormone-related protein(PTHrp) was first identified as the cause of hypercalcemia in malignancy. Hypercalcemia can be found in malignancy, especially in the epidermoid carcinoma of the lung, even without extensive metastases to the bones. The application of sensitive assays for PTHrp may help in the early diagnosis of lung cancer, in the monitoring of treatment and in the detection of recurrence. Method: Serum PTHrp was measured by radioimmunoassay detecting the N-terminal 1~34 peptide of human PTHrp(PTHrp 1-34) in 63 histologically confirmed lung cancer patients and 22 healthy controls. Result: Serum PTHrp(mean$\pm$S.E.) was $312{\pm}68.9pg/ml$ in 63 lung cancer patients and $158{\pm}38.2pg/ml$ in 22 controls(p>0.05). PTHrp was $356{\pm}103.9pg/ml$ in 34 epidermoid carcinoma patients, $281{\pm}148.7pg/ml$ in 15 adenocarcinoma patients and $316{\pm}140.8pg/ml$ in 9 small cell carcinoma patients. In epidermoid carcinoma patients, PTHrp was $570{\pm}472.3pg/ml$ in stage II(n=3; p<0.05 vs controls), $166{\pm}22.4pg/ml$ in stage IIIa(n=9), $282{\pm}113.3pg/ml$ in stage IIIb(n=12) and $668{\pm}367.9pg/ml$ in stage IV(n=9; p<0.05 vs controls). PTHrp was significantly increased in 8 epidermoid carcinoma patients with bone metastases($1526{\pm}811.2\;pg/ml$; p<0.0005 vs controls). Hypercalcemia was observed in an epidermoid carcinoma patient whose PTHrp value was 244 pg/ml. Conclusion: The serum PTHrp was increased in advanced epidermoid carcinoma patients even without hypercalcemia. The measurement of PTHrp may be not helpful in the early diagnosis of lung cancer. But the lung cancer should be suspected in the marked elevation of PTHrp. It may be of value in detecting patients of advanced diseases with bone metastases or patients who might develop the malignancy associated hypercalcemia.

  • PDF

The Influence of Aging on Pulmonary Function Tests in Elderly Korean Population (한국에서 노화에 따른 폐기능지표의 변화양상)

  • Lee, Jae-Myung;Kim, Eun-Jung;Kang, Min-Jong;Son, Jee-Woong;Lee, Seung-Joon;Kim, Dong-Gyu;Park, Myung-Jae;Lee, Myung-Goo;Hyun, In-Gyu;Jung, Ki-Suck
    • Tuberculosis and Respiratory Diseases
    • /
    • v.49 no.6
    • /
    • pp.752-759
    • /
    • 2000
  • Background : Many studies have shown that pulmonary function differs widely among race, age and geographical residency. By virtue of the improvement of nutrition and environment, the elderly population in Korea is markedly increasing and so are the ages of patients complaining respiratory symptoms. However, we do not have our own data on the pulmonary functional reserve of elderly persons in Korea. We evaluate the deterioration of pulmonary functional reserve and standardize the predictive values of pulmonary function in the elderly population. Method : Pulmonary function tests were conducted in 100 men and 100 women over the age of 65. We analyzed changes of FVC and $FEV_1$ according to age and height by linear regression. We compared our new multiple linear regression equation with other equations currently used in Korea. Results : In men, the mean age was $71.5{\pm}5.2$(mean${\pm}$SD) years and the mean height was $163.6{\pm}6.2$cm. The mean FVC was $3.42{\pm}0.49{\ell}$ and the mean $FEV_1, $2.72{\pm}v$. In women, the mean age was $72.0{\pm}5.1$ years and the mean height was $149.1{\pm}5.9$cm. The mean FVC was $2.22{\pm}0.42{\ell}$ and the mean $FEV_1$ $1.83{\pm}0.34{\ell}$. Multiple linear regression equation using age and height as an independent factors was as follows : FVC(${\ell}$)=1.857-0.0356$\times$age(year)+0.02517$\times$height(cm) (p<0.01, $R^2$=0.279), $FEV_1(${\ell}$)=1.340-0.02698$\times$age(year)+0.02021$\times$height(cm) (p<0.01, $R^2$=0.255) in men, FVC(${\ell}$) =-0.09765-0.03332$\times$age(year)+0.03164$\times$height(cm) (p<0.01, $R^2$=0.435), $FEV_1(${\ell}$)=-0.l69-0.02469$\times$age(year)+0.02539$\times$height(cm) (p<0.01, $R^2$=0.41) in women. Conclusion : We established prediction regressions for pulmonary functional tests in the elderly Korean population. We also confirmed that currently adopted equations do not exactly anticipate the expected pulmonary functional reserve in the aged person over 65 years old. We suggest that our new equations from this study should be applied to interpret the pulmonary function tests in the elderly population in Korea.

  • PDF

A comparative study on the correlation between Korean foods and the fractures of PFG and all ceramic crowns for posterior applications (구치용 도재소부금관과 전부도재관에 파절을 일으키는 한국음식에 관한 연구)

  • Kim, Jeong-Ho;Lee, Jai-Bong
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.47 no.2
    • /
    • pp.156-163
    • /
    • 2009
  • Statement of problem: Recently, there have been increased esthetic needs for posterior dental restorations. The failure of posterior dental ceramic restoration are possible not only by the characters of the component materials but also by the type of food. Purpose: The research aim was to compare the in vitro fracture resistance of simulated first molar crowns fabricated using 4 dental ceramic systems, full-porcelain-occlusal-surfaced PFG, half-porcelain-occlusal-surfaced PFG, Empress 2, Ice Zirkon and selected Korean foods. Material and methods: Eighty axisymmetric crowns of each system were fabricated to fit a preparation with 1.5- to 2.0-mm occlusal reduction. The center of the occlusal surface on each of 15 specimens per ceramic system was axially loaded to fracture in a Instron 4465, and the maximum load(N) was recorded. Afterwards, selected Korean foods specimens(boiled crab, boiled chicken with bone, boiled beef rib, dried squid, dried anchovy, round candy, walnut shell) were prepared. 15 specimens per each food were placed under the Instron and the maximum fracture loads for them were recorded. The 95% confidence intervals of the characteristic failure load were compared between dental ceramic systems and Korean foods. Afterwards, on the basis of previous results, 14Hz cyclic load was applied on the 4 systems of dental ceramic restorations in MTS. The reults were analyzed by analysis of variance and Post Hoc tests. Results: 95% confidence intervals for mean of fracture load 1. full porcelain occlusal surfaced PFG Crown: 2599.3 to 2809.1 N 2. half porcelain occlusal surfaced PFG Crown: 3689.4 to 3819.8 N 3. Ice Zirkon Crown: 1501.2 to 1867.9 N 4. Empress 2 Crown: 803.2 to 1188.5 N 5. boiled crab: 294.1 to 367.9 N 6. boiled chicken with bone: 357.1 to 408.6 N 7. boiled beef rib: 4077.7 to 4356.0 N 8. dried squid: 147.5 to 190.5 N 9. dried anchovy: 35.6 to 46.5 N 10. round candy: 1900.5 to 2615.8 N 11. walnut shell: 85.7 to 373.1 N under cyclic load(14Hz) in MTS, fracture load and masticatory cycles are: 1. full porcelain occlusal surfaced PFG Crown fractured at 95% confidence intervals of 4796.8-9321.2 cycles under 2224.8 N(round candy)load, no fracture under smaller loads. 2. half porcelain occlusal surfaced PFG Crown fractured at 95% confidence intervals of 881705.1-1143565.7 cycles under 2224.8 N(round candy). no fracture under smaller loads. 3. Ice Zirkon Crown fractured at 95% confidence intervlas of 979993.0-1145773.4 cycles under 382.9 N(boiled chicken with bone). no fracture under smaller loads. 4. Empress 2 Crown fractured at 95% confidence intervals of 564.1-954.7 cycles under 382.9 N(boiled chicken with bone). no fracture under smaller loads. Conclusion: There was a significant difference in fracture resistance between experimental groups. Under single load, Korean foods than can cause fracture to the dental ceramic restorations are boiled beef rib and round candy. Even if there is no fracture under single load, cyclic dynamic load can fracture dental posterior ceramic crowns. Experimental data with 14 Hz dynamic cyclic load are obtained as follows. 1. PFG crown(full porcelain occlusion) was failed after mean 0.03 years under fracture load for round candy(2224.8 N). 2. PFG crown(half porcelain occlusion) was failed after mean 4.1 years under fracture load for round candy(2224.8 N). 3. Ice Zirkon crown was failed after mean 4.3 years under fracture load for boiled chicken with bone(382.9 N). 4. Empress 2 crown was failed after mean 0.003 years under fracture load for boiled chicken with bone(382.9 N).