Comparison of the Surface Properties of 3D-printed Permanent Restorative Resins and Resin-based CAD/CAM Blocks.

OBJECTIVE: This study aimed to investigate the surface roughness, microhardness, and color changes of resin-based computer-aided design/computer-aided manufacturing (CAD/CAM) blocks and 3D-printed permanent resins in different beverages. METHODS AND MATERIALS: Resin-based CAD/CAM blocks (Cerasmart 270 and Grandio Blocs) and 3D-printed permanent restorative resins (Crowntec and Permanent Crown) were used in this study. A total of 96 specimens were prepared from CAD/CAM blocks and 3D-printed permanent resins. The initial surface roughness, microhardness, and shade value of the specimens were measured. Then, the specimens prepared from each material were divided into three subgroups (n=8) and immersed in tea, coffee, and distilled water for 30 days. After the specimens were immersed in the beverages, the surface roughness, microhardness, and tone values were measured again. The data were statistically analyzed using a two-way analysis of variance test (p<0.05). RESULTS: No statistically significant difference was found in the surface roughness values of the resin-based CAD/CAM blocks and 3D-printed resins (p<0.05). Resin-based CAD/CAM blocks showed statistically significantly higher microhardness than 3D-printed permanent resins (p<0.05). Although the color changes in 3D-printed resins in tea and coffee were similar to those in resin-based CAD/CAM blocks on the first and seventh days, more color changes appeared in the 3D-printed resins after 30 days. The surface roughness and microhardness values of the specimens submerged in tea, coffee, and distilled water showed no statistically significant changes (p<0.05). CONCLUSIONS: Although the surface roughness of 3D-printed permanent resins was similar to that of resin-based CAD/CAM blocks, they had a lower microhardness value. Moreover, 3D-printed permanent resins showed more color changes in tea and coffee.

Resistance of Single-shade Composites to Discoloration.

The aim of this study was to examine the color change of single-shade resin composites, which can be used for all tooth shades. In this study, samples were prepared using resin composites with single-shade (Omnichroma, Vitra Unique) and multishade composite systems (G-aenial A'Chord, Clearfil Majesty ES-2 Premium). The initial color values were measured with a spectrophotometer. Then, samples were kept in wine, coffee, black tea, and distilled water and color measurements were made after days 1, 7, and 30. Color change (ΔE00) and whiteness index (WID) values were statistically analyzed using a one-way analysis of variance (ANOVA) test (α=0.05). Single-shade resin composites showed more color change from wine, coffee, and black tea than multishade resin composites (p<0.001). Single-shade composites have a greater discoloration potential. Single-shade resin composites may show more color change from beverages than multishade resin composites, which may negatively affect clinical success.

[Gender-specific differences relating to depressiveness in 1st and 2nd generation migrants: results of a cross-sectional study amongst employees of a university hospital]. / Geschlechtsspezifische Unterschiede bezüglich Depressivität bei Migranten der ersten und zweiten Generation: Ergebnisse einer Querschnittsuntersuchung an Beschäftigten einer Universitätsklinik.

AIMS: This study analysed the risk of depression in men and women with a background of immigration by means of a cross-sectional study amongst employees of a German university hospital. In addition we identified gender-specific differences related to risk factors for depressiveness in the subgroups. METHODS: 7062 employees with or without a 1st (1G) or 2nd (2G) generation background of migration were questioned with regard to their socio-economic status, to single markers of acculturation, and to existing symptoms of depression assessed on the general depression scale (CES-D). Odds ratios (OR) were calculated using logistic regression. RESULTS: The response rate was 41.7% (n=2932). In comparison to non-migrants a higher risk of clinically relevant depressiveness was found for 1G male migrants (OR 2.35, 95% Cl 1.11-4.96), 1G female migrants (OR 1.94, 95% Cl 1.26-2.97) and for 2G female migrants (OR 1.82, 95% Cl 1.03-3.19). There was no significant increase in risk for 2G male migrants (OR 1.06, 95% Cl 0.31-3.62). 2G female migrants who considered themselves to retain a "close relationship to their native culture" had a significantly higher risk of depression than 2G male immigrants (OR 7.31; p = 0.032). Male 1G migrants without a "close relationship to their native culture" had a significantly higher risk of depression than those with a "close relationship to their native culture" (OR 5.79; p = 0.010). CONCLUSIONS: The results of this study point to gender-specific risk constellations for depression amongst 1st and 2nd generation migrants. It would appear that a strong orientation to the native culture increases the risk of depression for 2G female migrants, whereas for 1G male migrants this factor is associated with a lower risk of depression.

Antioxidant enzymes and paraoxonase show a co-activity in preserving low-density lipoprotein from oxidation.

Oxidative modification of low-density lipoprotein in the artery wall plays a crucial role in the development of atherosclerosis. This physiopathological mechanism is clearly inhibited by high-density lipoprotein possibly via paraoxonase enzyme activity, present in high-density lipoprotein. In this study, we determined the in vitro susceptibility of low-density lipoprotein to oxidation and the effect of various factors, such as paraoxonase phenotypes, on this process. Low-density lipoprotein from healthy volunteers (n=66) was isolated using the precipitant reagent and the oxidation was evaluated by measuring the malonyl dialdehyde and diene levels. Low-density lipoprotein cholesterol and phospholipid, vitamin E, serum cholesterol, high-density lipoprotein and low-density lipoprotein cholesterol levels, and erythrocyte antioxidant enzymes were also determined. There was no difference among the parameters with regard to gender. Low-density lipoprotein samples obtained from subjects with the AA allele were more prone to oxidation, as observed by their higher stimulated conjugated diene (P=0.041) and thiobarbituric acid-related substance (P=0.042) levels, than samples from subjects with AB or BB alleles. The subjects with the BB allele had higher superoxide dismutase (P=0.021) and catalase (insignificant increase) activities, while their conjugated diene (P=0.000) levels were lower. In conclusion, our results revealed that the high low-density lipoprotein oxidation is related to the high low-density lipoprotein cholesterol content and low phospholipid content. The present study demonstrated an increase in superoxide dismutase and catalase activities, as well as PON1 activities, in subjects with the BB allele. Since these enzymes all show activity against low-density lipoprotein oxidation, we propose that future investigations on atherosclerotic processes should address PON1 polymorphism as well as PON1 and other antioxidant enzymes.

MAO inhibitors and oxidant stress in aging brain tissue.

The process of aging presents itself with various alterations in physiological events. Among many theories, the free radical (FR) theory of aging which reflects the FR damage to cellular components is accepted as one of the most important theories. Recently, the increases in catecholamine metabolism in aging have also attracted attention, and monoamine oxidase (MAO), a key enzyme in this process has been extensively studied. The aim of this study was to assess the role of FR species via MAO, a possible source of FRs, in physiological aging by determining the lipid peroxidation products (LPP) (malondialdehyde, diene conjugates) and antioxidant enzyme levels (superoxide dismutase (SOD) and catalase (CAT) in young (3 months old, n=10) and aging (16-18 months old, n=10) rat brain tissues of Swiss male albino rats. In the second part of the study, the same parameters were determined after the acute administration of MAO inhibitors (deprenyl and pargyline, 25 mg/kg i.p.) to investigate whether these agents have any beneficial effects in reducing oxidant stress via inhibition of MAO. In old rat brains, MAO activities showed a significant increase (P=0.000) in addition to an insignificant increase in LPP, while SOD (P=0.007) and CAT activities showed a decrease with advancing age. After the acute administration of both deprenyl and pargyline, a significant decrease in the MAO activities of both young (P=0.0002 for each) and aging rats (P=0.0002 for deprenyl and P=0.0001 for pargyline) were observed. It was noted that deprenyl causes a significant increase in CAT activity (P<0.05) but a significant decrease in SOD activity (P<0.05) in young rats, while it causes only a significant increase in SOD activity in aging rats (P<0.05). Both deprenyl and pargyline cause a significant decrease in conjugated diene levels of aging rats (P<0.05). These results confirm the role of catecholamine oxidation and MAO activity as one of the causative factors in increased oxidant stress during aging. By reducing the oxidant stress observed in aging brain, MAO inhibitors, especially deprenyl, may contribute to the control of the aging process.

Age and sex related alterations in serum and platelet monoamine oxidase.

The process of aging presents itself with various alterations in physiological events. Although the turnover of catecholamines increases with aging, there is a lack of response to catecholamines in target tissues. One of the key enzymes in catecholamine metabolism is monoamine oxidase. It has been suggested that tissue and serum monoamine oxidase activities show pathological alterations in various diseases while physiological fluctuations can also be detected in normals. The aim of this study is to determine the sex and age related changes of platelet and serum monoamine oxidase in healthy volunteers. In this study, 75 healthy volunteers of different ages (21-80 a) and sexes (40 females, 35 males) were included. Serum and platelet monoamine oxidase determinations were performed spectrophotofluorometrically by Tufvesson's (Scand J Clin Lab Invest 1970; 26:151-4) and Kraml's (Biochem Pharmacol 1965; 14:1684-6) modified methods, respectively. While there was no significant difference in serum monoamine oxidase activities related to age and sex, platelet monoamine oxidase manifested a significant increase in females compared to males (p < 0.05) and the mean values in both sexes showed an increase with age (p < 0.001). The results of this study imply that platelet monoamine oxidase shows an age related increase which is more prominent in females.

Comparison of growth, serum prealbumin, transferrin, IgG and amino acids of term infants fed breast mild or formula.

This study was designed to compare growth parameters, biochemical indices of protein metabolism and serum amino acid patterns in newborn infants fed either human milk (n: 22) or formula with protein and amino acid concentrations similar to human milk (n: 19) during the first two months of life. Growth parameters were normal and similar in all infants. Serum levels of transferrin and IgG were not significantly different, whereas prealbumin concentrations were found to be significantly higher in infants fed formula compared to those fed human milk. In the formula group, glutamic acid and cystine levels were significantly lower while phenylalanine and proline were significantly higher compared to the breastfed group. It was observed that feeding a formula with an amino acid pattern similar to that of human milk does not necessarily give rise to identical patterns of amino acids or indices of protein metabolism.

Glucose metabolism and catecholamine responses during physical exercise in non-insulin-dependent diabetes.

Blood glucose, lactate, insulin, C-peptide, norepinephrine and epinephrine concentrations were determined in non-insulin-dependent diabetic patients and in healthy controls before, during and after moderate exercise, to evaluate the effects of physical exercise on glucoregulation. Ten diabetic and ten healthy control females bicycled 14 minutes at 60% of their maximal heart rates. In the diabetic patients, there were no significant changes in blood glucose levels post-exercise, while in controls the 60 minute post-exercise levels were higher than those measured in mid-exercise (p < 0.05). Lactate concentrations increased with exercise in both groups in a similar manner, with highest values at the end of exercise. No significant changes in insulin and C-peptide levels were induced with exercise in either group. Norepinephrine and epinephrine concentrations increased 2.5-3 fold with exercise in both groups (p < 0.05 for all values) but in the diabetics an earlier and prolonged catecholamine response was observed. We propose that catecholamines prevent hypoglycaemia during exercise when changes in insulin and C-peptide do not occur. In diabetic patients with good metabolic control, the glucoregulatory response to exercise is not worse than in anthropometrically similar controls with similar levels of fitness.

The effects of hydergine on the MAO activity of the aged and adult rat brain.

Despite the fact that hydergine has been used in the treatment of dementia for many years, its mechanism of action is still not clear. Current studies imply that the major effect of hydergine may be the modulation of synaptic neurotransmission rather than solely increasing blood flow as was once thought. A prominent feature that accompanies aging is an increase in monoamine oxidase (MAO) levels which results in decreased availability of catecholamines in the synaptic cleft. The aim of this study was to determine the effects of hydergine on the MAO activity in different brain regions (cortex, olfactory bulb, hypothalamus, hippocampus, striatum, cerebellum) of old (30 months) and adult (12 months) male Sprague-Dawley rats. In cortex and olfactory bulb MAO levels were higher in the aged group. In hippocampus and hypothalamus hydergine treatment caused significant decreases in MAO levels. An interaction between age and hydergine treatment was observed in the hypothalamus, hippocampus and cerebellum. The hydergine effect was more pronounced in the aged group in the hypothalamus and cerebellum, and more pronounced in the adult in the hippocampus. Our findings imply that increased brain MAO activity in aging can be modified by hydergine treatment in some brain regions.