The Comparison of Dysphagia between COVID-19 Pneumonia and Aspiration Pneumonia / 대한연하장애학회지

Objective@#Patients recovering from moderate-to-severe coronavirus disease 2019 (COVID-19) reportedly have dysphagia or difficulty in swallowing. The current study compares the differences in dysphagia characteristics arising from COVID-19 pneumonia and aspiration pneumonia. We further identify factors affecting the severity of dysphagia. @*Methods@#Fifty-four patients diagnosed with COVID-19 pneumonia with dysphagia and 44 patients with aspiration pneumonia were referred for a videofluoroscopic swallowing study (VFSS) since they presented with signs and symptoms of dysphagia. The electronic medical records were reviewed to compare the dysphagia characteristics of the patients. @*Results@#Intensive care unit (ICU) admission, intubation, tracheostomy, and a diagnosis of Acute Respiratory Distress Syndrome (ARDS) after admission were more common in patients with COVID-19 pneumonia (P＜0.001 for other variables and P=0.007 for tracheostomy) than in patients with aspiration pneumonia. Compared to patients with aspiration pneumonia, the COVID-19 patients had a significantly higher total modified videofluoroscopic dysphagia scale (mVDS) score, indicating more severe dysphagia (P=0.038). Among the mVDS sub-scores, tracheal aspiration was significantly higher in the COVID-19 pneumonia group (P＜0.001). In logistic regression analysis, age (P=0.034), COVID-19 (P=0.001), ICU admission (P=0.012), tracheostomy (P=0.029), and ARDS diagnosis after admission (P=0.036) were significantly associated with tracheal aspiration. After adjusting for age, sex, comorbidities, and clinical variables, COVID-19 was still significantly associated with worse tracheal aspiration scores (P=0.042). @*Conclusion@#Patients with COVID-19 pneumonia showed more severe dysphagia than subjects with aspiration pneumonia. This is particularly related to tracheal aspiration, as revealed by the VFSS. The dysphagia also correlated with a greater incidence of ICU admission, intubation, tracheostomy, and ARDS diagnosis in the COVID-19 pneumonia group.

Effect of cutting instruments on the dentin bond strength of a self-etch adhesive / 대한치과보존학회지

The purpose of this study was to compare the microshear bond strength of a self-etching primer adhesive to dentin prepared with different diamond points, carbide burs and SiC papers, and also to determine which SiC paper yield similar strength to that of dentinal surface prepared with points or burs. Fifty-six human molar were sectioned to expose the occlusal dentinal surfaces of crowns and slabs of 1.2 mm thick were made. Dentinal surfaces were removed with three diamond points, two carbide burs, and three SiC papers. They were divided into one of eight equal groups (n = 7); Group 1: standard diamond point(TF-12), Group 2: fine diamond point (TF-12F), Group 3: extrafine diamond point (TF-12EF), Group 4: plain-cut carbide bur (no. 245), Group 5: cross-cut carbide bur (no. 557), Group 6 : P 120-grade SiC paper, Group 7: P 220-grade SiC paper, Group 8: P 800-grade SiC paper. Clearfil SE Bond was applied on dentinal surface and Clearfil AP-X was placed on dentinal surface using Tygon tubes. After the bonded specimens were subjected to uSBS testing, the mean uSBS (n = 20 for each group) was statistically compared using one-way ANOVA and Tukey HSD test. In conclusion, the use of extrafine diamond point is recommended for improved bonding of Clearfil SE Bond to dentin. Also the use of P 220-grade SiC paper in vitro will be yield the results closer to dentinal surface prepared with fine diamond point or carbide burs in vivo.

Influence of appication time of self-etching primers on dentinal microtensile bond strength / 대한치과보존학회지

This study evaluated the influence of application time of self-etching primers on microtensile bond strength (microTBS) to dentin using three self-etching primer adhesive systems. Dentin surfaces were exposed from forty-eight human molars. They were conditioned with three self-etching primers (Clearfil SE Bond [SE], Unifil Bond [UF], Tyrian SPE + One Step Plus [TY]) and different primining times (10s, 20s, 30s and 40s). Composite resins were bonded to dentin surfaces and specimens were made. microTBS was tested and statistically compared using by one-way ANOVA and Tukey's Test The results of this study presented that priming time for 10s in SE and UF groups and for 30s and 40s in TY group was highly decreased microTBS to dentin.

Color changes in composite resins exposed to xenon lamp / 대한치과보존학회지

The purpose of this study was to evaluate the color changes of the composite resin resulting from xenon lamp exposure in different environments. Composite resin (Z 250 ; shade A1, A2, A3, A3.5, and A4) were applied in a cylindrical metal mold. Seventy five specimens according to environments of exposure were made as follows; Group I: aluminum foiling of the specimens in the air at 37degrees C for 1 day and 7 days. Group II: exposure of xenon lamp to the specimens in the air at 37degrees C for 1 day and 7 days. Group III: exposure of xenon lamp to the specimens in distilled water at 37degrees C for 1 day and 7 days. The color characteristics (L*,a*,b*) of the specimens before and after exposure of xenon lamp were measured by spectrophotometer and the total color differences (DeltaE*) were computed. The results obtained were as follows: 1. In all groups except A1 shade of group III, the DeltaE* values presented below 2.0, and group III showed the highest DeltaE* values followed by group II and group I in a decreasing order(p<0.05). 2. In all shades and groups, the more the exposure time of xenon lamp and the lighter the shade were, the higher the tendency for discoloration (p<0.05). 3. The composite resins which was exposed to xenon lamp in the distilled water was more discolored than those in the air (p<0.05). 4. The major changes of composite resins which were exposed to xenon lamp in the air were an increase in yellowness through a positive shift of the b* value, and those in the distilled water were an increase in darkness and yellowness through a negative shift of the L* value and a positive shift of the b* value.

Shear bond strength of self-etching adhesives to dentin and sem analysis / 대한치과보존학회지

The purpose of this study was to compare shear bond strength and interfacial pattern of composite bonded to dentin using self-etching adhesive systems. Sixty extracted human molars with exposed occlusal dentin were divided into four groups and bonded with four adhesives and composites: Single Bond/Filtek Z 250(SB), Tyrian SPE-One-Step Plus/Aelitefil(TY), Prompt L-Pop/Filtek Z 250(LP), and One-Up Bond F/Palfique Toughwell(OU). The results of this study were as follows; 1. Shear bond strength for OU was significantly lower than that of other groups(p<0.05). No significant difference was founded among SB, TY, and LP. 2. Failure modes to dentin showed adhesive and mixed for SB, TY, and LP, but them for OU showed adhesive in all spceimens. 3. Dentin-resin interface showed close adaptation for SB, TY, and LP, but it showed gap for OU. 4. The hybrid layers for TY, LP, OU were thinner than that of SB. Adhesive layers were observed between composite and hybrid layer, which were 5 microm thick for TY and 10 microm thick for OU.

The influence of IRM temporary restorations on marginal microleakage of dentin adhesives / 대한치과보존학회지

This study investigated the influence of IRM on marginal microleakage of 5th generation adhesives. Class V cavities with gingival margins in dentin were prepared on both buccal and lingual surfaces of 60 extracted human molar teeth. Prepared teeth were randomly divided into six groups. Group 1 and 4 received no temporary restoration with IRM. Group 2 and 5 were covered with IRM mixed at P/L ratio(10g/1g). Group 3 and 6 were covered with IRM mixed at P/L ratio(10g/2g). The temporary restorations were removed mechanically with an ultrasonic scaler after one-week storage in distilled water. The cavities were restored using one of two adhesives and composites; Single Bond/Filtek Z 250(Group 1, 2 and 3), UniFil Bond/UniFil F(Group 4, 5 and 6). Following one day storage in distilled water, the restored teeth were thermocycled for 500 cycles(between 5degrees C and 55degrees C) and immersed in 2% methylene blue for dye penetration testing. The results were analysed using Kruskal-Wallis Test, Mann-Whitney and Wilcoxon signed ranked test at a significance level of 0.05. The results of this study were as follows: 1. Ranking of mean microleakage scores at the enamel margins was Group 10.05). 4. At the dentin margins, the microleakage of the group not pretreated with IRM was lower than that of the group pretreated with IRM. And the microleakage of UniFil Bond was lower than that of Single Bond. 5. Compared with microleakages between the enamel and dentin margins of each groups, Group 1, 2, 3, 4, 5 and 6 at dentin margin were higher microleakage than those at enamel margin. There were significant difference between enamel and dentin microleakage of Group 2 and 3(p<0.05).

Effect of a rewetting agent on dentin adhesion / 대한치과보존학회지

This study compared the dentin adhesion to composite resin according to air-dry, blot dry, application of rewetting agent on air-dry or blot dry dentin surface by microleakag test and SEM observation. For microleakage test, class V cavity preparations with dentinal margins were prepared on both buccal and lingual surfaces of 40 extracted human molars. For SEM observation, occlusal dentin of 20 extracted human molars were exposed. After etched the dentin, prepared teeth were randomly divided into four groups; D group: air dry for 10-15 sec., B group: blot dry with moist cotton pellet, D-R group: air dry and rewet with Aqua-Prep F for 20 sec., B-R group: blot dry and rewet with Aqua-Prep F for 20 sec. Treated cavities and surfaces were filled or constructed using One-Step adhesives and Aelitefil composite resins. Specimens were stored in distilled water for 24 hours. For microleakage test, the specimens were thermocycled and soaked into 2% methylene blue. The specimens were sectioned longitudinally and evaluated for microleakage under steromicroscope. The data were statistically analysed by Kruskal-Wallis Test, Mann-Whitney and Wilcoxon signed ranked tests. For SEM observation, the specimens were bisectioned mesiodiatally. After decalcified and deproteinized, specimens were observed under SEM. The results of this study were as follows; 1. The microleakges on dentinal margin were the highest in D group compared with B group, D-R group, and B-R group(p<0.05). But there was no significant difference between B group, D-R group and B-R group. 2. D group showed gap and a few resin tags between dentin and composite resin. 3. B group, D-R group, and B-R groups showed close adaptation between dentin and composite resin. It showed that resin rags in B group were numerous and long, in D-R group were few and short, in B-R group were numerous and short or long. 4. Adhesive layer showed in D-R group (10 microm) and B-R group (3 microm) In conclusion, use of rewetting agent to dry dentin was efficient to dentin adhesion, also it did not provide reverse effect on blot dry dentin.

Morphological patterns of self-etching primers and self-etching adhesive bonded to tooth structure / 대한치과보존학회지

The purpose of this study was to compare in vitro interfacial relationship of restorations bonded with three self-etching primer adhesives and one self-etching adhesive. Class I cavity preparations were prepared on twenty extracted human molars. Prepared teeth were divided into four groups and restored with four adhesives and composites: Clearfil SE Bond/Clearfil(TM) AP-X (SE), UniFil Bond/UniFil(R) F (UF), FL Bond/Filtek(TM) Z 250 (FL) and Prompt L-Pop/Filtek(TM) Z 250 (LP) After storing in distilled water of room temperature for 24 hours, the specimens were vertically sectioned and decalcified. Morphological patterns between the enamel/dentin and adhesives were observed under SEM. The results of this study were as follows; 1. They showed close adaptation between enamel and SE, UF and FL except for LP. 2. The hybrid layer in dentin was 2 microm thick in SE, 1.5 microm thick in UF, and 0.4 microm in both FL and LP. So, the hybrid layers of SE and UF were slightly thicker than that of FL and LP. 3. The lengths and diameters of resin tags in UF and FL were similar, but those of LP were slightly shorter and slenderer than those of SE. 4. The resin tags were long rod shape in SE, and funnel shape in other groups. Within the limitations of this study, it was concluded that self-etching primer adhesives showed close adaptation on enamel. In addition, the thickness of hybrid layer ranged from 0.4-1.5 microm between adhesives and dentin. The resin tags were long rod or funnel shape, and dimension of them was similar or different among adhesives.

Age Changes and Sex Differences in Serum Dehydroepiandrosterone Sulfate (DHEAS) Concentrations & its related factors throughout Adulthood

BACKGROUND : DHEAS, the major circulating adrenal hormone, has been suggested to have a role in many aging related diseases and perhaps in aging itself. But, there is no epidemiologic data of DHEAS in normal adults in Korea. We studied age changes and sex differences in serum DHEAS & its related factors throughout adulthood. METHODS : We administ structured questionnaires to the study subjects. We measured serum DHEAS levels and several biochemical markers (total cholesterol, triglyceride, HDL-cholesterol, glucose etc) in 1.710 healthy men(857) and women (853), aged 17-76 years. We also measured their height, weight, waist & hip circumference and body fat contents with bioimpedance method. We analyzed various variables relating to serum DHEAS levels by using SPSS. Reference data of serum DHEAS level in normal adults were also suggested. RESULTS : The DHEAS concentration peaked at age group blow age of 30 years in man(260.9 microgram/dL). Then mean values declined steadily in both sexes (r=-0.38, por=2 times/week, 219.1 vs 185.3 microgram/dL, p0.85, 227.1 vs 197.4 microgram/dL) after adjusting age. DHEAS was positively correlated with body mass index (r=0.12, p<0.01). But in women, drinkers (154.3 vs 131.7 microgram/dL, p<0.05) and regular exercise group (146.1 vs 131.6 microgram/dL, p=0.05) had higher mean DHEAS value. There were no significant association between DHEAS and lipid profile (total cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol) & fasting glucose level in both sex. CONCLUSION : Our data suggest that DHEAS levels may influenced by several sociodemographic factors (e.g. smoking, alcohol, exercise etc) and body mass index. DHEAS level was inversely correlated by age in both sex and men had 1.5 times higher DHEAS values than women. We could not find any association between DHEAS level and lipid profile & fasting blood sugar.

A Case of Hepatitis B Virus Associated Nephropathy / 영남의대학술지

Since Combes' first description of hepatitis B virus associated membranous glomerulonephritis, many reports have shown a strong association of hepatitis B virus infection with various types of nephropathies, especially membranous glomerulonephritis and membranoproliferative glomerulonephritis. Recently, the authors experienced a case of membranoproliferative glomerulonephritis, type I in a 16-year-old male patient with persistent HBs and HBe antigenemia. One year prior to admission the patient was told of hepatitis at routine check, but he remained asymptomatic throughout. He was admitted to our hospital with chief complaints of proteinuria and microscopic hematuria found on routine urinalysis. Liver and kidney biopsy revealed chronic persistent hepatitis and membranoproliferative glomerulonephritis type I, respectively. We report a case of hepatitis B virus associated nephropathy with review of the literatures. Considering the endemic nature of hepatitis B virus infection in Korea, the incidence of hepatitis B virus associated nephropathy would be proportionally high in comparison with those of other countries. So, the importance of this entity merits special consideration in our country. Further study concerning pathogenesis, epidemiology, and treatment may be needed.