Increasing demands for zirconia material in clinics, assessment of biocompatibility of zirconia is essential. In this article, a review of in vitro studies of zirconia compatibility was performed. Zirconia showed great biocompatibility at in vitro studies with various cell lines such as fibroblasts, osteoblasts, and lymphocytes. Many studies reported that zirconia caused no cytotoxicity or mutation. Zirconia also showed less bacterial adhesion. There were no adverse effects except for small reduced strength with in vitro study mimicking long-term exposure of body fluid. According to the study with ostoblast-like cells, zirconia could regulate genes of immunity, molecular transport, and cell cycle. Such gene regulating was considered as one of the reasons of zirconia biocompatibility. With biocompatibility of zirconia powders, in vitro studies had controversial conclusions. It seems that zirconia powders might have cytotoxicity
Bacterial Adhesion ; Body Fluids ; Cell Cycle ; Cell Line ; Fibroblasts ; In Vitro Techniques* ; Lymphocytes ; Osteoblasts ; Powders

Increasing demands for esthetic dental treatment, zirconia, which has high mechanical and esthetic properties, had been applied more and more in clinics. Therefore, assessment of biocompatibility of zirconia is necessary. In this article, a review of in vivo studies of zirconia compatibility was performed. In vivo studies showed zirconia had great biocompatibility both on soft and hard tissue. Studies with various animals and patients reported high biocompatibility of zirconia. In terms of bone synthesis and bone adhesion, zirconia showed similar biocompatible properties to titanium. On the other hand, zirconia could be used as implant. For using as an implant, various methods of Hydroxyapatite (HA) coating had been suggested. Since HA coating on titanium implant showed some problems such as low bonding strength and degeneration of HA, HA-zirconia composite, HA-coated zirconia, and HA-zirconia functionally graded material (FGM) or intermediate layer of alumina had been proposed. These methods showed higher bonding strength and biocompatibility.
Aluminum Oxide ; Animals ; Durapatite ; Hand ; Humans ; Titanium

Purpose: This study aimed to evaluate the effectiveness of exercise in patients with hemophilia. Methods: We carried out a systematic review and meta-analysis in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis guidelines. A literature search was conducted of published randomized controlled trials for exercise interventions from January 1, 2014 to March 15, 2023. To estimate the size of the effects of exercise, a meta-analysis was performed using the R package “meta.” Results: Five databases were searched to obtain articles published in Korean or English. Of 1,150 articles reviewed, 13 were included in the systematic review and 9 in the meta-analysis. The risk of bias was assessed using RoB 2.0. Results: The overall effect sizes of exercise interventions, calculated as the standardized mean difference, were -0.11 (95% confidence interval [CI] = -1.41 to –1.20) for pain, -2.13 (95% CI = -3.33 to -0.93) for joint health, 9.96 (95% CI = 7.51 to 12.28) for physical activity, and 0.59 (95% CI = -0.39 to -1.56) for quality of life. Conclusion These findings suggest that exercise is useful for improving the joint health and physical activity of patients with hemophilia. Thus, it is necessary to develop and apply exercise interventions for patients with hemophilia to reduce their pain and improve their quality of life.

OBJECTIVE: This study evaluated the presence of residual root canal filling material after retreatment using micro-computed tomography (micro-CT). MATERIALS AND METHODS: Extracted human teeth (single- and double-rooted, n = 21/each; C-shaped, n = 15) were prepared with ProFile and randomly assigned to three subgroups for obturation with gutta-percha and three different sealers (EndoSeal MTA, EndoSequence BC sealer, and AH Plus). After 10 days, the filling material was removed and the root canals were instrumented one size up from the previous master apical file size. The teeth were scanned using micro-CT before and after retreatment. The percentage of remaining filling material after retreatment was calculated at the coronal, middle, and apical thirds. Data were analyzed using the Kruskal-Wallis test and Mann-Whitney U test with Bonferroni post hoc correction. RESULTS: The tested sealers showed no significant differences in the percentage of remaining filling material in single- and double-rooted teeth, although EndoSeal MTA showed the highest value in C-shaped roots (p < 0.05). The percentage of remaining filling material of AH Plus and EndoSeal MTA was significantly higher in C-shaped roots than in single- or double-roots (p < 0.05), while that of BC sealer was similar across all root types. EndoSeal MTA showed the highest values at the apical thirds of single- and double-roots (p < 0.05); otherwise, no significant differences were observed among the coronal, middle, and apical thirds. CONCLUSIONS: Within the limitations of this study, a large amount of EndoSeal MTA remained after retreatment, especially in C-shaped root canals.
Dental Pulp Cavity ; Gutta-Percha ; Humans ; Pemetrexed ; Retreatment ; Root Canal Obturation ; Tooth

BACKGROUND: This study purposed to analyze the relationship between regional obesity rates and regional variables. METHODS: Data was collected from the Korean Statistical Information Service (KOSIS) and Community Health Survey in 2012. The units of analysis were administrative districts such as city, county, and district. The dependent variable was the age-sex adjusted regional obesity rates. The independent variables were selected to represent four aspects of regions: health behaviour factor, psychological factor, socio-economic factor, and physical environment factor. Along with the traditional ordinary least square (OLS) regression analysis model, this study applied geographically weighted regression (GWR) analysis to calculate the regression coefficients for each region. RESULTS: The OLS results showed that there were significant differences in regional obesity rates in high-risk drinking, walking, depression, and financial independence. The GWR results showed that the size of regression coefficients in independent variables was differed by regions. CONCLUSION: Our results can help in providing useful information for health policy makers. Regional characteristics should be considered when allocating health resources and developing health-related programs.
Depression ; Drinking ; Health Policy ; Health Resources ; Health Surveys ; Information Services ; Obesity* ; Psychology ; Walking

Metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUO) are differentiated by the presence of cardiometabolic risk factors (CMRFs) and insulin resistance (IR). This study aimed to evaluate the prevalence and clinical characteristics of MHO in Korean children and adolescents and to investigate the anthropometric, laboratory, and lifestyle predictors of MHO. This study included data from 530 obese subjects, aged 10–19 years, obtained from the Fourth Korea National Health and Nutrition Examination Survey. Subjects were classified into MHO and MUO groups according to the presence of CMRF (MHO(CMRF)/MUO(CMRF)) and degree of IR (MHO(IR)/MUO(IR)). Demographic, anthropometric, cardiometabolic, and lifestyle factors were compared between the groups. Logistic regression analysis and receiver operating characteristic curve analysis were performed to identify factors that predicted MHO. The prevalence of MHO(CMRF) and MHO(IR) in obese Korean youth was 36.8% (n = 197) and 68.8% (n = 356), respectively. CMRF profiles were significantly less favorable in MUO children. Longer and more vigorous physical activity and less protein intake were associated with MHO(CMRF) phenotype. The best predictors of MHO(CMRF) and MHO(IR) were waist circumference (odds ratio [OR], 0.82; 95% confidence interval [CI], 0.77–0.88; P < 0.001) and body mass index (BMI) standard deviation score (OR, 0.24; 95% CI, 0.15–0.39; P < 0.001), respectively. The prevalence of MHO differed depending on how it was defined. To adequately manage obesity in youth, the approach to individuals with MHO and MUO should be personalized due to variation in clinical characteristics. Longitudinal studies are needed to evaluate long-term consequences of MHO.
Adolescent* ; Body Mass Index ; Child* ; Humans ; Insulin Resistance ; Korea* ; Life Style ; Logistic Models ; Longitudinal Studies ; Motor Activity ; Nutrition Surveys* ; Obesity ; Obesity, Metabolically Benign* ; Phenotype ; Prevalence* ; Risk Factors ; ROC Curve ; Waist Circumference

OBJECTIVES: Dry eye disease (DED) is an increasingly important public health problem in Korea. Previous studies conducted in Korea have reported inconsistent results regarding the protective effects of vitamin D on DED, and these discrepancies may be related to the relatively simple questionnaire that has been used. Thus, we evaluated the association of serum vitamin D levels with DED using the ocular surface disease index (OSDI). METHODS: The present study evaluated data from participants in the Study Group for Environmental Eye Disease (2014-2015). This group included data from 752 participants, and data from 740 participants (253 men and 487 women) were analyzed in the present study. DED severity was evaluated using the OSDI. RESULTS: Higher serum vitamin D levels were associated with a non-significantly reduced risk of DED in the crude analysis (odds ratio [OR], 0.991; 95% confidence interval [CI], 0.971 to 1.011) and in the adjusted analysis (OR, 0.988; 95% CI, 0.966 to 1.010). In the crude analysis of no/mild DED vs. moderate/severe DED, men exhibited a decreased risk with increasing serum vitamin D levels (OR, 0.999; 95% CI, 0.950 to 1.051), while women exhibited an increased risk (OR, 1.003; 95% CI, 0.979 to 1.027). In these analyses, we found no significant associations. CONCLUSIONS: The findings of the present study support previous reports that serum vitamin D levels are not associated with DED.
25-Hydroxyvitamin D 2 ; Dry Eye Syndromes ; Eye Diseases* ; Female ; Humans ; Keratoconjunctivitis Sicca ; Korea ; Male ; Public Health ; Vitamin D* ; Vitamins*

BACKGROUND: Suicide is one of important health problems in Korea. Previous studies showed factors associated with suicide in individual levels. However, suicide was influenced by society that individuals belong to, so it was required to analyze suicide in local levels. The purpose of this study was to analyze the regional disparities of suicide mortality by gender and the association between local characteristics and suicide mortality. METHODS: This study included 229 city.county.district administrative districts in Korea. Age- and sex-standardized suicide mortality and age-standardized suicide mortality (male/female) were used as dependent variables. City.county.district types, socio-demographics (number of divorces per 1,000 population, number of marriages per 1,000 population, and single households), financial variable (financial independence), welfare variable (welfare budget), and health behavior/status (perceived health status scores and EuroQol-5 dimension [EQ-5D]) were used to represent the local characteristics. We used hot-spot analysis to identify the spatial patterns of suicide mortality and negative binomial regression analysis to examine factors affecting suicide mortality. RESULTS: There were differences in distribution of suicide mortality and hot-spot regions of suicide mortality by gender. Negative binomial regression analysis provided that city.county.district types (city), number of divorces per 1,000 population, financial independence, and EQ-5D had significant influences on the age- and sex-standardized suicide mortality per 100,000. Factor influencing suicide mortality was the number of divorces per 1,000 population in both male and female. CONCLUSION: Study results provided evidences that suicide mortality among regions was differed by gender. Health policy makers will need to consider gender and local characteristics when making policies for suicides.
Divorce ; Female ; Health Policy ; Humans ; Korea ; Male ; Marriage ; Mortality* ; Spatial Analysis ; Suicide*

BACKGROUND: This study explored the relationship between hospital resources and services uses in outpatient/inpatient-based hospital service area (HSA) in Korea. METHODS: Study hospitals included all acute care hospitals except tertiary hospitals. Inpatient and outpatient hospital claims from the Korean National Health Insurance (NHI) program in 2010 were used to identify the service uses. Hospital resources and the degree of insurance premium in study areas were identified with the NHI corporation data. Study variables were computed by summing the service uses or hospital resources of study hospitals in each HSA. Service uses were represented by the total medical charges and number of visits/inpatient days. Hospital resources were measured by number of beds, number of doctors, and number of computed tomography (CT). The economic status of NHI enrollees in each HSA was controlled by the average monthly premium of NHI program per household in each HSA. The degree of using local hospitals was controlled with the localization index. RESULTS: Analysis results showed that hospital resources such as beds, CT were statistically related to the service uses. And also localization index was found to have positive significant relationships with service uses. CONCLUSION: Hospital resources such as beds, CT had not only positive impacts on inpatient service uses, but also influences on the outpatient setting. Health policy makers will require monitoring and assessing the hospital resources in Korea.
Family Characteristics ; Health Policy ; Health Resources ; Humans ; Inpatients ; Insurance ; Korea ; National Health Programs ; Outpatients ; Tertiary Care Centers

PURPOSE: The forehead flap is the workhorse in nasal reconstruction, which provides a similar skin color, texture, structure, and reliability. There are some disadvantages, including donor site morbidities, 2- or 3-stage operations, and postoperative management after initial flap transfer. Furthermore, there has been little attention to the exposed raw surface wound, after the first stage of an operation. This article describes the authors??modification to overcome this problem, using artificial collagen membrane. METHODS: An Artificial collagen membrane is composed of an outer silicone membrane and an inner collagen layer. After a forehead flap elevation, the expected raw surface was covered by an artificial collagen membrane with 5-0 nylon suture. A simple dressing, which had been applied to the site, was changed every 2 or 3 days in an outpatient unit. At 3 weeks postprocedure, a second stage operation was performed. RESULTS: With biosynthetic protection of the raw surface, there were no wound problems, such as infection or flap loss. Thus, the patient was satisfied due to an effortless management of the wound and a reduction in pain. CONCLUSION: The application of an artificial collagen membrane to the raw under-surface of the flap could be a comfortable and a protective choice for this procedure.
Bandages ; Collagen ; Forehead ; Humans ; Membranes ; Membranes, Artificial ; Nose Deformities, Acquired ; Nylons ; Outpatients ; Silicones ; Skin ; Surgical Flaps ; Sutures ; Tissue Donors