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: 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 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: 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*

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

PURPOSE: Few studies have investigated the marginal accuracy of 3-unit zirconia fixed partial dentures (FPDs) fabricated by computer-aided design/computer-aided manufacturing (CAD/CAM) system. The purpose of this study was to compare the marginal fit of zirconia FPDs made using two CAD/CAM systems with that of metal-ceramic FPDs. MATERIALS AND METHODS: Artificial resin maxillary central and lateral incisors were prepared for 3-unit FPDs and fixed in yellow stone. This model was duplicated to epoxy resin die. On the resin die, 15 three-unit FPDs were fabricated per group (45 in total): Group A, zirconia 3-unit FPDs made with the Everest system; Group B, zirconia 3-unit FPDs made with the Lava system; and Group C, metal-ceramic 3-unit FPDs. They were cemented to resin dies with resin cement. After removal of pontic, each retainer was separated and observed under a microscope (Presize 440C). Marginal gaps of experimental groups were analyzed using one-way ANOVA and Duncan test. RESULTS: Mean marginal gaps of 3-unit FPDs were 60.46 microm for the Everest group, 78.71 microm for the Lava group, and 81.32 microm for the metal-ceramic group. The Everest group demonstrated significantly smaller marginal gap than the Lava and the metal-ceramic groups (P<.05). The marginal gap did not significantly differ between the Lava and the metal-ceramic groups (P>.05). CONCLUSION: The marginal gaps of anterior 3-unit zirconia FPD differed according to CAD/CAM systems, but still fell within clinically acceptable ranges compared with conventional metal-ceramic restoration.
Denture, Partial, Fixed ; Incisor ; Resin Cements ; Zirconium

Excessive occlusal wear causes loss of tooth structure, occlusal plane disharmony, impaired function and esthetic problems. Although the decrease of occlusal vertical dimension may be compensated by the growth of alveolar bone and tooth eruption, minimal increase of occlusal vertical dimension may be required for esthetics and retention of prosthesis. In this case, a 44-year-old male patient visited Seoul National University Dental Hospital with chief complaint of severe tooth wear and shade disharmony. Based on assessment of diagnostic wax-up, 3 mm increase of occlusal vertical dimension was determined. Removable occlusal splint and interim prosthesis was used to ascertain patient's comfort and adaptation. After the adaptation period, definitive prosthesis fabricated with full-contour monolithic zirconia were delivered and the patient was recommended to wear a nightguard device for prosthesis protection. This report presents a case of full mouth rehabilitation with the elevation of patient's occlusal vertical height, resulting in satisfactory esthetics and functions.
Adult ; Dental Occlusion ; Dentition* ; Esthetics ; Humans ; Male ; Mouth Rehabilitation* ; Mouth* ; Occlusal Splints ; Prostheses and Implants* ; Seoul ; Tooth ; Tooth Attrition ; Tooth Eruption ; Tooth Wear ; Vertical Dimension