Objective: This study examined the frequency of emergency department visits for syncope according to the day, week, and month. The frequency of syncope associated with holidays and the locations was also investigated. Methods: A retrospective study was performed on the frequency of patients discharged from the emergency department with a diagnosis of syncope from July 2016 to June 2017. Each 24-hour period was analyzed in four-hour intervals, and the frequency of occurrence was calculated for weekly and monthly time frames. In addition, the frequency of syncope associated with holidays and the locations where syncope occurred were analyzed for any possible trends. Results: For the 259 patients in this study, the frequency of the reflex syncope was significantly higher between 6 and 10 am (P=0.011), and showed a decreasing trend since that period (P=0.006). The number of reflex syncope visits on Mondays was significantly higher than on the other days (P<0.001) and a decreasing trend after Monday toward the weekend (P=0.023). A significant difference in the frequency of syncope associated with holidays was observed: 0.48 on weekdays, excluding the day after a holiday; 0.37 on a holiday; and 0.92 on the day after a holiday (P<0.001). Almost half of the reflex syncope events (44.3%) occurred in the subway. Conclusion The frequency of syncope was highest in the morning. In addition, reflex syncope showed a higher frequency on the day after a holiday, and the incidence was higher in the subway.

PURPOSE: This study aimed to identify the scores of postpartum depression(PPD) on the first day, 1st week, and 6th week after the delivery and to explore their related factors before and after delivery in postpartum women. METHODS: With a survey design, 293 postpartum women were recruited from a postpartum unit, Ilsin Christian hospital in Pusan via convenience sampling and were followed at 1st week and 6th week in the outpatient clinic. RESULTS: Results showed that the scores of PPD(EPDS score) were low at postpartum 1st day, 1st week and 6th week but prevalence of PPD(EPDS > or =13) was 3.1% at 1st day, 8.2% at 1st week and 7.5% at 6th week, respectively. The pre-delivery factors were experience of depression, and the post-delivery factors were baby's sex(1st day), no caregiver for baby(1st week), and no help and concern for taking care of baby from husband and family(1st day and 6th week). The greater satisfaction with becoming a mother and her life, and greater maternal attachment were related to lower level of PPD at the three time points. CONCLUSION: Regular screening for postpartum depression and supportive and informative education is needed for postpartum women visiting the outpatient clinic for follow-up.
Ambulatory Care Facilities ; Caregivers ; Depression ; Depression, Postpartum ; Female ; Follow-Up Studies ; Humans ; Mass Screening ; Mothers ; Postpartum Period ; Prevalence ; Spouses ; Tuberculin

PURPOSE: Fracture of the veneering material of zirconia restorations frequently occurs in clinical situations. The purpose of this in vitro study was to compare the fracture strengths of zirconia crowns veneered with various ceramic materials by various techniques. MATERIALS AND METHODS: A 1.2 mm, 360degrees chamfer preparation and occlusal reduction of 2 mm were performed on a first mandibular molar, and 45 model dies were fabricated in a titanium alloy by CAD/CAM system. Forty-five zirconia copings were fabricated and divided into three groups. In the first group (LT) zirconia copings were veneered with feldspathic porcelain by the layering technique. In the second group (HT) the glass ceramic was heat-pressed on the zirconia coping, and for the third group (ST) a CAD/CAM-fabricated high-strength anatomically shaped veneering cap was sintered onto the zirconia coping. All crowns were cemented onto their titanium dies with Rely X(TM) Unicem (3M ESPE) and loaded with a universal testing machine (Instron 5583) until failure. The mean fracture values were compared by an one-way ANOVA and a multiple comparison post-hoc test (alpha=0.05). Scanning electron microscope was used to investigate the fractured interface. RESULTS: Mean fracture load and standard deviation was 4263.8+/-1110.8 N for Group LT, 5070.8+/-1016.4 for Group HT and 6242.0+/-1759.5 N for Group ST. The values of Group ST were significantly higher than those of the other groups. CONCLUSION: Zirconia crowns veneered with CAD/CAM generated glass ceramics by the sintering technique are superior to those veneered with feldspathic porcelain by the layering technique or veneered with glass ceramics by the heat-pressing technique in terms of fracture strength.
Alloys ; Ceramics ; Collodion ; Crowns ; Dental Porcelain ; Electrons ; Glass ; Molar ; Titanium ; Zirconium

There have been many studies about marginal discrepancy of single restorations made by various systems and materials.But many of statistical inferences are not definite because of sample size,measurement number,measuring instruments,etc. The purpose of this study was to compare the marginal adaptations of the anterior single restorations made by different systems and to consider more desirable statistical methods in analysing the marginal fit.The in vitro marginal discrepancies of three different all-ceramic crown systems(Celay In-Ceram,Conventional In-Ceram,IPS Empress 2 layering technique)and one control group (PFM)were evaluated and compared.The crowns were made from one extracted maxillary central incisor prepared with a 1mm shoulder margin and 6 taper walls by milling machine.10 crowns per each system were fabricated.Measurements of a crown were recorded at 50 points that were randomly selected for marginal gap evaluation.Non-parametric statistical analysis was performed for the results. Within the limits of this study,the following conclusions were drawn: 1.Mean gap dimensions and standard deviations at the marginal opening for the maxillary incisor crowns were 98.2+/-40.6 mu m for PFM,83.5+/-18.7 mu m for Celay In-Ceram,104.9+/-44.1 mu m for conventional In-Ceram,and 45.5+/-11.5 mu m for IPS Empress 2 layering technique.The IPS Empress 2 system showed the smallest marginal gap (P<0.05).The marginal openings of the other three groups were not significantly different (P<0.05). 2.The marginal discrepancies found in this study were all within clinically acceptable standards(100 150 mu m). 3.When the variable is so controlled that the system may be the only one,mean value is interpreted to be the marginal discrepancy of a restoration which is made by each system and standard deviation is to be technique-sensitivity of each one. 4.From the standard deviations,the copy-milling technique (Celay/In-Ceram)was not considered to be technique-sensitive in comparison with other methods. 5.Parametric analysis is more reliable than non-parametric one in interpretation of the mean and standard deviation.The sample size of each group has to be more than 30 to use parametric statistics. The level of clinically acceptable marginal fit has not been established.Further studies are needed.
Crowns* ; Incisor ; Sample Size ; Shoulder

PURPOSE: The purpose of this study was to develop a dental image processing system using a three-dimensional (3D) camera and stereovision technology. The reliability of the system for measuring axial wall convergence angles was evaluated. MATERIALS AND METHODS: The new system predicted 3D coordinate points from 2D images and calculated distances and angles between points. Two examiners measured axial wall convergence angles for seven artificial abutments using a traditional tracing-based method (TBM) and the stereovision-based method (SVBM). Five wax abutment models of simplified abutment forms were made and axial wall convergence angles of wax models were measured by both methods. The data were statistically analyzed at the level of significance, 0.05. RESULTS: Intraclass correlation coefficients showed excellent intra-examiner and inter-examiner reliabilities for both methods. Bland-Altman plots and paired t-tests showed significant differences between measurements and true values using TBM; differences were not significant with SVBM. CONCLUSION: This study found that the SVBM reflected true angle values more accurately than a TMB and illustrated an example of 3D computer science applied to clinical dentistry.
Dentistry

PURPOSE: Unpredictable shrinkage of zirconia during sintering process causes discrepancy. Therefore, there have been attempts to reduce discrepancy by milling zirconia after sintering. However, due to the hardness of sintered zirconia, milling takes longer time, causes damage to the machine and causes chip formation. With customized zirconia block using the mean dimension of prepared natural dentition, it is expected to overcome these shortcomings. MATERIALS AND METHODS: The mean dimension of prepared natural dentition was analyzed as STL file after scanning of prepared teeth treated at SNUDH. The transverse, frontal and sagittal planes were set using Mimics and Photoshop. 3D volume was projected on each plane, and the outer line was measured through external tangent line, and the inner line was measured through inflection point of tangent line. RESULTS: The mean height of prepared incisal (N = 57) is 6.60 ± 1.05 mm, mesiodistal length is 2.98 ± 0.73 mm, buccolingual length is 2.04 ± 0.73 mm. The mean height of prepared premolar (N = 15) is 5.37 ± 1.49 mm, mesiodistal length is 4.10 ± 1.78 mm, buccolingual length is 5.86 ± 1.55 mm. And the mean height of prepared molar (N = 13) is 5.11 ± 1.29 mm, mesiodistal length is 6.80 ± 1.18 mm, buccolingual length is 7.34 ± 1.40 mm. CONCLUSION: Using the mean dimension of prepared natural dentition, it is expected to be able to fabricate customized zirconia block.
Bicuspid ; Dentition ; Hardness ; Molar ; Tooth*

People with class I intellectual disability need lifelong assistance and protection from their surroundings due to impaired adaptive functioning. They have poor oral health and show higher prevalence of dental caries, periapical inflammation and tooth loss that require proper prosthetic restoration. Because removable prostheses for intellectually disabled patients often lack stability, retention, and maintenance, fixed prostheses are essential and the only available option is dental implants. In this case, a 45 year-old male patient with class I intellectual disability had poor oral hygiene with most of his teeth missing and visited the clinic to recover his masticatory function. Due to such systemic conditions, the definitive restoration of choice was the implant-supported fixed dental prosthesis made of biocompatible and highly strong monolithic zirconia. In consequence of the treatment process, the patient was able to improve his oral environment aesthetically and functionally.
Dental Caries ; Dental Implants ; Dental Prosthesis ; Humans ; Inflammation ; Intellectual Disability* ; Male ; Mouth Rehabilitation* ; Mouth* ; Oral Health ; Oral Hygiene ; Prevalence ; Prostheses and Implants ; Tooth ; Tooth Loss

PURPOSE: The purpose of this study was to investigate the cutting efficiency of coarse grit diamond burs with air-turbine handpiece on natural tooth. MATERIALS AND METHODS: Four groups of coarse grit diamond bur were selected: Komet (A), Shofu (B), Premier (C), and Mani (D). The extracted maxillary central incisors were used, and ten cuts were made on each specimen, using the rotary diamond burs. The surface of each bur was measured at the upper, middle, and bottom of the bur with confocal laser scanning microscope and imaged with SEM. The data were analyzed with one-way ANOVA and t-test at the significance level of 0.05. RESULTS: The surface roughness was measured. At the A diamond bur, the Sa values were 52.93 microm, 48.32 microm, 46.79 microm, 45.06 microm, and 43.43 microm for control, test 1, 2, 3, and 4 respectively. The Sa values were 50.68 microm, 45.62 microm, 44.41 microm, 44.10 microm, and 42.46 microm for B diamond bur, 58.02 microm, 55.53 microm, 52.22 microm, 48.26 microm, and 45.36 microm for C diamond bur, and 50.11 microm, 46.73 microm, 45.46 microm, 42.58 microm, and 41.80 microm for D diamond bur. Surface roughness after each bur use showed significant changes, but no significant difference was found in surface roughness change between bur systems. CONCLUSIONS: Surface roughness in the same bur system showed significant differences after each tooth preparation. However no statistically significant differences were found in surface roughness between bur systems. The SEM images between control and test 4 showed the abraded particles.
Diamond ; Humans ; Incisor ; Tooth ; Tooth Preparation

PURPOSE: The aim of this study was to compare the film thicknesses of several resin cements as a function of time after mixing and to examine the effect of working time on the film thicknesses. MATERIALS AND METHODS: The film thickness (microm) of 4 resin cements (n=10), 1 composite resin (Panavia F 2.0), 3 self-adhesive resin (Clearfil SA luting, Zirconite, RelyX U200) cements was measured at 20-second intervals after mixing of the cements up to 200 seconds under a load of 50 N. Linear regression was fitted to verify the effect of working time on the film thickness of each cement. Data were compared to the working time recommended by manufacturers using Wilcoxon test (alpha=.05). RESULTS: All of the materials showed a positive linear correlation between the film thickness and working time. There was no statistically significant difference between the working time based on our results and the values recommended by the manufacturers even though there was a discrepancy between those two values. CONCLUSION: The film thickness of resin cements could increase with the increase of working time. Working time to meet the ISO standard of 50-microm maximum film thickness could be different from the manufacturer's recommended value.
Linear Models ; Resin Cements ; Resins, Synthetic*

STATEMENT OF PROBLEM: Various anodic oxidation techniques can be applied to dental implant surfaces. But the condition for optimal anodized surfaces has not been described yet. PURPOSE: The purpose of this investigation was to compare an implant that was oxidized by another method with TiUnite(TM) through resonance frequency analysis and histomorphometry. MATERIAL AND METHODS: Turned (control), TiUnite(TM) and another oxidized fixtures, which used Ca2+ solution for anodic oxidation, were placed in the tibiae of 5 New Zealand White rabbits. The bone responses were evaluated and compared by consecutive resonance frequency analysis once a week for 6 weeks and histomorphometry after a healing period of 6 weeks. RESULTS: At the first week, both oxidized implants showed significantly higher implant stability quotient (ISQ) values than the control. No significant differences in resonance frequency analysis were found between the two oxidized groups for 6 weeks. The means and standard deviations of bone-to-implant contact (BIC) ratios were 71.0 +/- 4.2 for TiUnite(TM), 67.5 +/- 10.3 for the Ca2+-based oxidation fixture, 22.8 +/- 6.5 for the control. Both oxidized implants were significantly superior in osseointegration to the turned one. There was, however, no statistically significant difference between the two oxidized implants. CONCLUSION: TiUnite(TM) and the Ca2+ -based oxidation fixture showed superior early bone response than the control with respect to resonance frequency analysis and histomorphometry. No significant differences between the oxidized groups, however, were found in this investigation using the rabbit tibia model.
Dental Implants ; Osseointegration ; Rabbits ; Tibia*