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: The purpose of this study was to evaluate the influence of porcelain re-firing on the formation of surface bubble and on the change in shade of metal-ceramic crown exposed to artificial saliva. MATERIALS AND METHODS: Thirty disk-shaped specimens were made in 10 mm diameter with 0.5 mm metal core thickness and 1 mm ceramic thickness. A spectroradiometer was used to determine the CIE Lab coordinates. The number and size of surface bubble were observed with a stereomicroscope. After the exposure to artificial saliva for 7 days, re-firing was performed at glazing temperature. After re-firing, the CIE Lab were calculated, and the number and size of surface bubble were observed again. The change in shade was expressed with DeltaE. Statistical analysis was done with paired t-test for the change in the number of surface bubble and student t-test for the change in the size of surface bubble (alpha= 0.05). RESULTS: Shade difference was calculated 2.14 DeltaE units. The mean number of surface bubble was 1.33 +/- 1.49 before re-firing, 3.27 +/- 2.90 after re-firing. After re-firing, the number of surface bubble was significantly increased (P<.05). The mean size of surface bubble was 81.97 +/- 32.03 microm before re-firing, 142.94 +/- 47.40 microm after re-firing. After re-firing, the size of surface bubble was significantly increased (P<.05). CONCLUSION: Shade change after re-firing was perceptible (DeltaE < 2.0) and clinically acceptable (DeltaE < 3.7). The number and size of surface bubble was significantly increased after re-firing. Further investigation to decrease the surface bubble on the extra oral repair of metal-ceramic crown, will be needed in future study.
Ceramics ; Crowns ; Dental Porcelain ; Humans ; Pyridines ; Saliva, Artificial ; Thiazoles

PURPOSE: Resonance frequency analysis, Periotest, and removal torque (RT) test were known as the methods to assess implant stability. The results of these methods are affected by the bone condition, implant diameter and shape. The purpose of this study is to access the meaning and the correlationship of the resonance frequency analysis, Periotest and RT test in osseointegration simulated acrylic resin when the engaged bone thickness and peri-implant bone defect are changed. MATERIALS AND METHODS: To simulate osseointegration, the fixture was fixed to an aluminum mold with a screw. Acrylic resin powder and liquid were poured into the mold for polymerization. The engaged resin thickness with implant was controlled. Simulated cortical bone thicknesses were 1, 3, 5 and 10 mm. Additional 1, 3 and 5 mm peri-implant bone defects were simulated. Three types of implants were used; 4 mm diameter implants of straight shape, 4 mm diameter implants of tapered shape and 5 mm diameter implants of tapered shape. Five fixtures per each type were tested in respective bone condition. Resonance frequency analysis and Periotest were evaluated in all bone conditions. Peak removal torque was measured at simulated cortical bone thicknesses of 1 and 3 mm. The statistical analysis was performed with the Kruskal-Wallis test, Mann-Whitney U test, and Spearman test using a 95% level of confidence. RESULTS: With increasing engaged bone depth, the Implant Stability Quotient (ISQ) values increased and the Periotest values (PTVs) decreased (P<.001, P<.001). With increasing peri-implant bone defect, ISQ values decreased and PTVs increased (P<.001). When the diameter of implant increased, ISQ values increased and Periotest values (PTV) decreased (P<.001). There was a strong correlation between ISQ values and PTVs (r = -0.99, P<.001). Furthermore, the peak removal torque values had weak correlations with both ISQ values and PTVs (r = 0.52, P<.001 ; r = -0.52, P<.001). CONCLUSION: This study confirmed favorable implant stability with increasing engaged bone depth and implant diameter and decreasing peri-implant bone defect. ISQ values and PTVs showed strong correlation with each other and not with the peak removal torque values.
Aluminum ; Fungi ; Osseointegration ; Polymerization ; Polymers ; Torque

PURPOSE: The aim of this study was to investigate effect of specimen preparation method on the microtensile bond strength of veneering ceramic to zirconia core. MATERIALS AND METHODS: Cylindrical Lava zirconia block (3M ESPE, Seefeld, Germany) was cut into discs using a diamond disc. After sintering, the core specimens were placed in an adjustable mold and veneered with Lava ceram (3M ESPE, Seefeld, Germany). The disc shaped specimen of group 1 was cut into microbars (1x1x7 mm3) using a low speed diamond disc under water cooling (n = 15). The specimen of group 2 was cut into microbars (1.2x1.2x7 mm3) in the same way. Whereafter the microbars were trimmed (1x1x7 mm3) using a thick diamond disc under water cooling (n = 15). The microtensile bond strength was tested in a microtensile tester (Instron 8848, Instro(R) Co., Norwood, USA). Fractured microtensile specimens were analyzed under a stereomicroscope (MZ6, Leica Microsystems GmbH, Wetzlar, Germany) at magnification x30. RESULTS: The microtensile bond strength of group 1 (28.8 +/- 7.0 MPa) was significantly higher than group 2 (11.0 +/- 3.3 MPa) (P=.00). CONCLUSION: It appears advisable to avoid the trimming action, especially high strength ceramic specimens.
Ceramics ; Diamond ; Fungi ; Water ; Zirconium

PURPOSE: The purpose of this study was to assess the marginal fit of three-unit bridges produced using LAVA CAD/CAM (computer-aided design/computer-aided manufacturing) system and conventional PFG in vitro. MATERIALS AND METHODS: #11, 13 resin teeth were prepared on dentiform, then duplicated. Twenty resin models were fabricated, ten for PFG 3-unit bridges and ten for LAVA 3-unit bridges. Each bridge was cemented on the resin model. Marginal discrepancy was measured with stereoscopic microscope (Nikon DS-Fi 1, Nikon, Japan) at a magnification of x75. Independent t-test was done for the statistical analysis. RESULTS: The mean marginal discrepancy values and standard deviations of the PFG bridges was 97.1 +/- 18.7 microm for incisors, 76.6 +/- 21.8 microm for canines; that of the LAVA bridges was 90.4 +/- 26.7 microm for incisor, 110.2 +/- 30.2 microm for canines. The mean marginal discrepancy between PFG and LAVA for incisor did not show significant difference (P>.05). But for canine, the mean marginal discrepancy of PFG bridges was smaller than that of LAVA bridges (P<.05). CONCLUSION: The LAVA CAD/CAM 3-unit bridges and the PFG 3-unit bridges showed clinically acceptable marginal discrepancy.
Incisor ; Tooth

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: 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: 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*

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