Effects of Material Thickness and Pretreatment on the Interfacial Gap of Translucent Zirconia Restorations with Self-adhesive Resin Cement.

PURPOSE: The first objective was to determine if the dual-curing of self-adhesive resin cement (SAC) with reduced light penetrating through zirconia had an effect on interfacial gap of zirconia restorations. The second purpose was to examine whether pretreatment methods for universal adhesive affected interfacial gap. The last aim was to compare the microhardness of SAC polymerized under different zirconia thicknesses. METHODS AND MATERIALS: This study evaluated self-adhesive resin cement (RelyX U200, 3M ESPE) after different pretreatment with universal adhesive (Single Bond Universal, 3M ESPE) under different polymerization conditions. CAD/CAM inlay cavities were prepared on extracted third molars. Translucent zirconia restorations were milled using Katana UTML (Kuraray). The teeth were divided into three groups: Groups I, II, and III in which the restoration thicknesses were 1, 2, and 3 mm. Each Group had three subgroups according to different pretreatment methods. For subgroup-1, no pretreatment was done on the prepared cavity. For subgroup-2, universal adhesive was applied and light-cured before cement placement (precure method). For subgroup-3, universal adhesive was applied; however, light-curing was done after cement placement (cocure method). After thermo-cycling, the interfacial gap at the restoration-tooth interface was investigated using swept-source optical coherence tomography imaging. Finally, microhardness was measured for SAC under different zirconia thicknesses. For statistical analysis, the interfacial gap was analyzed using two-way analysis of variance (ANOVA) to test the effect of cavity depth and pretreatment. In terms of each cavity depth and pretreatment, the interfacial gap was compared using one-way ANOVA and Scheffe's test. One-way ANOVA was also performed for comparison of the Vickers hardness results. RESULTS: Different thicknesses of the restoration resulted in differences in interfacial gaps except between the precure method of Groups I and II (p<0.05). The effect of universal adhesive pretreatment was different depending on the restoration thickness with exceptions in Groups I and III (p<0.05). Vickers hardness number decreased as the low radiant exposure of light was applied (p<0.05). CONCLUSION: Interfacial gap of zirconia restorations can differ depending on the material thickness, pretreatment, and activation mode. Reduced light intensity penetrating through zirconia may lead to higher interfacial gap percentage and lower microhardness of the self-adhesive resin cement. Application of a universal adhesive showed similar or reduced interfacial gaps in the cement space.

Interfacial Evaluation of CAD/CAM Resin Inlays on the Cavity Floor Using Swept-source Optical Coherence Tomography.

CLINICAL RELEVANCE: When a resin nanoceramic inlay is cemented using self-adhesive cement, a universal dentin adhesive can be applied to the prepared cavity. The application of the adhesive before self-adhesive cement placement provides similar or better interfacial adaptation than without the adhesive. SUMMARY: Purpose: The first objective of this study was to determine whether the luting material used for computer-aided design and computer-aided manufacture resin nanoceramic inlays affected interfacial adaptation. The second objective was to investigate whether application of a universal dentin adhesive before cementation affected interfacial adaptation. The final objective was to compare the inlay-side and dentin-side interfaces in the cement space.Methods and Materials: Seventy-four class I cavities were prepared on extracted human third molars. Cavities were optically scanned, and resin nanoceramic inlays were milled using Lava Ultimate blocks (3M ESPE). For the control groups, the fabricated inlays were cemented using Panavia V5 (Kuraray Noritake) or FujiCem 2 (GC). For the experimental groups, the teeth were randomly divided into groups I and II. Group I contained four subgroups using different luting materials; in all subgroups, the inlays were cemented and dual cured without pretreatment. Group II contained six subgroups in which inlays were cemented and dual cured after application of a universal dentin adhesive. After thermocycling, interfacial adaptation was measured using swept-source optical coherence tomography (SS-OCT) imaging and statistically compared among groups.Results: Interfacial adaptation was different depending on the luting material used (p<0.05). After application of a universal adhesive, some subgroups showed improved interfacial adaptation (p<0.05). In the comparison of inlay-side and dentin-side interfaces, no difference was found in interfacial adaptation (p>0.05).Conclusions: Interfacial adaptation for resin nanoceramic inlays differed with luting material. For some self-adhesive cements, application of a universal adhesive before cementation improved interfacial adaptation.

Association between dental pain and depression in Korean adults using the Korean National Health and Nutrition Examination Survey.

The purpose of this study was to evaluate the relationships between the prevalence of depression and dental pain using a well characterised, nationally representative, population-based study. This study analysed data from the 2012 Korea National Health and Nutrition Examination Survey (n = 4886). Oral health status was assessed using the oral health questionnaire, and oral examination was performed by trained dentists. Depression was defined as the participant having been diagnosed as depression during the previous year. Logistic regression was applied to estimate adjusted odds ratios (AOR) and 95% confidence intervals (CI), controlling for a range of covariates. Results demonstrated that participants included in 'root canal treatment is necessary' showed higher prevalence of self-reported dental pain; in particular, participants with depression presented more dental pain than those without depression. After adjusting for sociodemographic factors, self-reported dental pain increased in participants with depression. The AOR (95% CI) for having self-reported dental pain was 1·58 (1·08-2·33) in dentists' diagnosis of no dental pain/depression group, 1·62 (1·32-1·98) in dentists' diagnosis of dental pain/no depression group and 2·84 (1·10-7·37) in dentists' diagnosis of dental pain/depression group. It was concluded that depression was associated with dental pain after adjustment for potential confounders in Korean adults. Thus, dentists should consider the possible presence of psychopathology when treating patients with dental pain.

Risk factors for damaged liver function after chemotherapy in hepatitis B virus carriers with non-Hodgkin lymphoma.

The goal of this study was to investigate damaged liver function after chemotherapy in hepatitis B virus (HBV) carriers with non-Hodgkin lymphoma (NHL) and to evaluate risk factors associated with a high risk of damaged liver function. Clinical histories of 134 HBV carriers with NHL who were treated with chemotherapy were obtained and analyzed for the occurrence of damaged liver function and other related high-risk factors. Analysis showed that 76 patients (56.7%) had damaged liver function after chemotherapy: 6 patients (7.9%) had I degree, 17 patients (22.4%) had II degree, 20 patients (26.3%) had III degree, and 33 patients (43.4%) had IV degree damage. After treatment, 18 patients (23.7%) continued to receive chemotherapy according to their original schedule, 39 patients (51.3%) delayed chemotherapy, 16 patients (21.1%) stopped chemotherapy, and 3 patients (3.9%) died. Analysis of a binary multivariate logistic regression model showed that administration of steroids was a high-risk factor for damaged liver function after chemotherapy in NHL patients. The incidence of damaged liver function after chemotherapy is high among HBV carriers with NHL; therefore, administration of steroid chemotherapy is a high-risk factor.

A seroepidemiology study of varicella among children aged 0-12 years in Taiwan.

The epidemiology pattern of varicella appears to vary among regions with different climates, population densities, and degrees of development. This study investigated the age-specific varicella zoster virus (VZV) seroprevalence in children aged 0 to 12 years in Taiwan and compared these seroprevalences between free and private vaccination areas. Residual sera were collected from 13 hospitals with 1,401 valid samples. Immunoglobulin G antibodies to VZV were measured by enzyme-linked immunosorbent assay. Parents of 656 children answered questions about the varicella incidence and varicella vaccination history of their children. In the 8-12 year-olds, the seroprevance ranged between 88.0-93.8% in northern, central, and eastern, while it was only 76.1% in southern Taiwan. The seroprevalence of children 0-5 years old were significantly different between free and private vaccination areas. Seropositive children who reported no history of varicella or receiving varicella vaccine accounted for 26.1-59.3% of the total positive cases. Our findings suggest the possible effects of climate, geographical conditions, and lifestyle on the seroepidemiology of VZV in Taiwan. The efforts of implementing a varicella vaccination program in Taiwan should focus on reaching high levels of coverage.

Mesenchymal stem/progenitor cells developed in cultures from UC blood.

Background Whether umbilical cord blood (UCB) serves as a source of mesenchymal stem/progenitor cells (MSPC) is controversial. MSPC are the best candidates for cellular therapy of orthopedic skeletal tissues. In order to explore the possibility of UCB as a useful source of MSPC, we identified, expanded in culture, and characterized MSPC from UCB harvests on a large scale. Methods Mononuclear cells isolated from UCB harvests (n=411) were cultured in media supplemented with 10% FBS. MSPC-like cells cultured from each UCB harvest were expanded ex vivo by successive subcultivation. UCB harvests with a more than 1000-fold expanding capacity (n=9) were examined for surface Ag phenotypes and in vitro differentiation potentials into osteogenic, chondrogenic and adipogenic lineages. Results Ninety-five out of a total of 411 UCB units (23.1%) generated MSPC-like cells during cultivation. Nine UCB units (2.2%) yielded MSPC with more than 1000-fold expansion capacity. These cells positively expressed MSPC-related Ag, but did not express myeloid, histocompatibility or endothelial Ag. These cells also possessed multiple capacities for osteogenic, chondrogenic and adipogenic differentiation. Discussion Although the incidence of UCB harvests producing MSPC in culture was low, some of them showed a more than 1000-fold expanding capacity, which is enough in cell numbers to be an allogeneic source for cellular therapy. Our results may encourage the use of UCB as an attractive target for allogeneic cellular therapeutic options in tissue engineering.

Retinoic acid-mediated induction of neurons and glial cells from human umbilical cord-derived hematopoietic stem cells.

Recent studies reporting trans-differentiation of mononucleated cells derived from human umbilical cord blood into neuronal cells aroused interest among investigators for their clinical implication and significance in regenerative medicine. In the present study, purified populations of hematopoietic stem cells were isolated via magnetic bead sorting and fluorescence-activated cell sorter (FACS) using a specific CD133 antibody, a cell type-specific marker for hematopoietic stem cells, and grown in culture in the presence of retinoic acid (RA). CD133+ hematopoietic stem cells expressed neuronal and glial phenotypes after RA treatment. RT-PCR analysis indicated that the RA treated CD133+ cells expressed mRNA transcripts for ATP-binding cassettes transporter ABCG2 (a universal stem cell marker), nestin (a specific cell type marker for neural stem cells), Musashi1 (a specific marker for neural stem cells) and RA receptors (RAR) including RAR-alpha, RAR-beta, and retinoid X receptor (RXR)-gamma. RA-treated CD133+ cells expressed mRNA transcripts for neuron-specific markers neurofilament proteins (NF-L, -M, -H) and synaptophysin as determined by RT-PCR, structural proteins characteristic of neurons including tubulin beta III and neuron specific enolase (NSE) by Western blot, and neuron-specific markers NeuN and microtubule-associated protein-2 (MAP2) by immunocytochemistry. RA-treated CD133+ cells also expressed the astrocyte-specific marker glial fibrillary acidic protein (GFAP), as demonstrated by RT-PCR, Western blot, and immunocytochemistry. In addition, RA-treated CD133+ cells expressed cell type-specific markers for oligodendrocytes including myelin basic protein (MBP) as shown by RT-PCR, proteolipid protein (PLP) by Western blot analysis, and cyclic nucleotide phosphodiesterase (CNPase) by immunostaining. Upregulated expression of several basic helix-loop-helix (bHLH) transcription factors important for early neurogenesis, including Otx2, Pax6, Wnt1, Olig2, Hash1 and NeuroD1, was also demonstrated in CD133+ cells after RA treatment. These results indicate that human cord blood-derived CD133+ hematopoietic stem cells could trans-differentiate into neural cell types of neuron-like cells, astrocytes, and oligodendrocytes by RA treatment.

Apolipoprotein E polymorphism and serum lipoprotein(a) concentrations in a Korean male population.

The purpose of this study was to investigate the effect of apolipoprotein E polymorphism on lipoprotein(a) metabolism by comparing serum lipoprotein(a) concentration with apolipoprotein E genotype in a Korean male population whose high molecular weight (HMW) lipoprotein(a) frequency was 95-98%. Serum lipoprotein(a), total cholesterol, triglyceride and high-density lipoprotein-cholesterol concentrations were measured and the apolipoprotein E genotype determined in 1189 healthy Korean males. The medians of serum lipoprotein(a) concentration in the apo E 2/3 group (0.105 g/L) and the apo E 3/4 group (0-116 g/L) were significantly lower than that in the apo E 3/3 group (0.155 g/L; P < 0.001). The medians of serum triglyceride were 1.497 mmol/L in the apo E 2/3 group, 1.356 mmol/L in the apo E 3/4 group, and 1.452 mmol/L in the apo E 3/3 group (P<0.05). With the significant difference in the serum lipoprotein(a) concentration in Korean males according to apolipoprotein E genotype, and with the negative correlation between serum triglyceride concentration and serum lipoprotein(a) concentration, it is suggested that apolipoprotein E polymorphism and serum triglyceride participate in the metabolism of lipoprotein(a) with HMW.

Influence of holding temperature on the growth and survival of Salmonella spp. and Staphylococcus aureus and the production of staphylococcal enterotoxin in egg products.

In this study, growth and survival of Salmonella spp. and Staphylococcus aureus in steamed egg and scrambled egg held at 5, 18, 22, 37, 55 and 60 degrees C are investigated. The production of staphylococcal enterotoxin in steamed egg is also examined. Results reveal that Salmonella spp. and Staph. aureus in the egg products multiply best at 37 degrees C, followed closely by 22 and 18 degrees C. Neither pathogen showed growth in the egg products held at 5 degrees C. Initial inoculation dose, holding temperature and holding time affected the population of both organisms found in the egg products. Staphylococcal enterotoxin A (SEA) and B (SEB) are detected only in the egg products held at 37 or 22 degrees C. After holding at 37 degrees C for 36 h, scrambled egg inoculated with ca. 5.0 log cfu/g Staph. aureus contains the highest levels of SEA (> 64 ng/g) and SEB (> 64 ng/g). Although Salmonella spp. and Staph. aureus grow better in steamed eggs than in scrambled eggs, production of staphylococcal enterotoxin, in general, was higher in scrambled eggs than in steamed eggs. On the other hand, a repaid destruction of the test organisms in steamed eggs held at 60 degrees C was observed. Holding the steamed eggs at 60 degrees C, Salmonella spp. and Staph. aureus with an initial population of ca. 5.9 and 5.6 log cfu/g, respectively, reduced to a non-detectable level in 1 h.

In vivo antioxidant effect of green tea.

OBJECTIVE: The object of this study was to investigate the in vivo antioxidant effect of green tea and dosage effect of green tea on antioxidant effect. DESIGN: We tested 10 healthy subjects (aged 23-25 y, five women and five men) with overnight fasting. The total antioxidant capacity of plasma was measured at baseline and 60 min and 120 min after ingestion of 150 ml green tea. Green tea was prepared by infusing 2.5 g of dried green tea leaves for 2 min at 80 degrees C in 150 ml of water. In the second week, they took 300 ml of tea (5.0 g of green tea leaves) and, in the third week, 450 ml of tea (7.5 g of green tea leaves). The total antioxidant capacities of plasma were determined with a Total Antioxidant Kit (Randox Laboratories Ltd, UK) using a Cobas Mira analyser (Roche Diagnostic Systems Inc., Switzerland). The mean intra-assay coefficient of variation was 1.2%. RESULTS: The total antioxidant capacity of plasma increased by 1.1% at 60 min and 2.1% at 120 min over baseline value in subjects consuming 150 ml of green tea, which was statistically not significant. However, total antioxidant capacity of plasma after consuming 300 ml of green tea showed a significant increase of 7.0% after 60 min and 6.2% after 120 min (P<0.0001), and after consuming 450 ml 12.0% after 60 min and 12.7% after 120 min over baseline value (P<0.0001). CONCLUSIONS: Total antioxidant capacity of plasma was significantly increased after taking green tea in amounts of 300 and 450 ml. A positive increment according to green tea dosage was also observed. SPONSORSHIP: This work was funded by the Pacific Corporation (Korea).

Growth and survival of Escherichia coli O157:H7 and Listeria monocytogenes in egg products held at different temperatures.

Growth and survival of Escherichia coli O157:H7 and Listeria monocytogenes in steamed eggs and scrambled eggs held at different temperatures (5, 18, 22, 37, 55, and 60 degrees C) were investigated in the present study. Among the holding temperatures tested, both pathogens multiplied best at 37 degrees C followed by 22, 18, and 5 degrees C. In general, E. coli O157:H7 grew better in the egg products than L. monocytogenes did at all the storage temperatures tested except at 5 degrees C. E. coli O157:H7 did not grow in steamed eggs and scrambled eggs held at 5 degrees C. L. monocytogenes showed a slight population increase of approximately 0.6 to 0.9 log CFU/g in these egg products at the end of the 36-h storage period at 5 degrees C. The population of both pathogens detected in the egg products was affected by the initial population, holding temperature, and length of the holding period. It was also noted that L. monocytogenes was more susceptible than E. coli O157:H7 in steamed eggs held at 60 degrees C. After holding at 60 degrees C for 1 h, no detectable viable cells of L. monocytogenes with a population reduction of 5.4 log CFU/g was observed in steamed eggs, whereas a lower population reduction of only approximately 0.5 log CFU/ml was noted for E. coli O157:H7.

Distribution of haptoglobin phenotypes in a Korean population, using the semi-automated PhastSystem.

We have established a new phenotyping method for haptoglobin, based on sodium dodecyl sulphate-polyacrylamide gel electrophoresis using the PhastSystem (Pharmacia Biotech, Uppsala, Sweden), followed by immunoblotting for detection. We measured haptoglobin concentrations and determined the haptoglobin phenotypes of 316 healthy Koreans using this method: 31 (9.8%) were of Hp 1-1 type, 140 (44.3%) of Hp 2-1 type and 145 (45.9%) of Hp 2-2 type. The haptoglobin allele frequencies were calculated to be 0.32 for Hp1 and 0.68 for Hp2. We were able to visualize up to 12 bands from the human Hp 2-2 polymeric series, with molecular weights in the range 171.9 x 10(3) to 802.2 x 10(3). The reference range of serum haptoglobin concentrations obtained by the IFCC (International Federation of Clinical Chemistry) standard method was 0.27-2.14 g/L. The serum haptoglobin concentration in Koreans was similar to that of Caucasians, but the Hp1 allele frequency was lower in Koreans. Our method could be used in clinical laboratories as a simple and practical method of haptoglobin phenotyping. In addition, the Hp 2-2 polymeric series could be used as high molecular weight standards.