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Feher Balazs Frommlet Florian Lettner Stefan Gruber Reinhard Nemeth Letizia Elisabeth Ulm Christian Kuchler Ulrike 《Clinical oral investigations》2021,25(11):6093-6099
Clinical Oral Investigations - With only limited information available on dimensional changes after jaw cyst surgery, postoperative cyst shrinkage remains largely unpredictable. We aimed to propose... 相似文献
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Elmadfa I Rust P Majchrzak D Wagner KH Genser D Lettner R Pinter M 《International journal for vitamin and nutrition research. Internationale Zeitschrift für Vitamin- und Ern?hrungsforschung. Journal international de vitaminologie et de nutrition》2004,74(2):147-152
AIM: The objective of this study was to examine whether increasing doses of beta-carotene supplements have effects on biological markers of lipid peroxidation in healthy volunteers. SUBJECTS AND METHODS: Forty-two healthy subjects were supplemented with 5 mg, 10 mg, 20 mg or 40 mg beta-carotene/day, respectively for five weeks. Plasma beta-carotene and tocopherol levels, malondialdehyde-thiobarbituric reactive substances (MDA-TBARS), and conjugated dienes were determined using high-performance liquid chromatography (HPLC). Concentrations of ascorbic acid, uric acid, and the total antioxidative capacity (TAC) in plasma were measured photometrically. RESULTS: Plasma beta-carotene levels increased significantly according to the intervention dose (p < 0.001), and concentrations of tocopherol equivalents and ascorbic acid were within the physiological range except in the 5 mg intervention group where a significant decrease of vitamin C was assessed (p < 0.05). Uric acid in plasma decreased significantly in all groups (p < 0.05) up to the end of investigation, but was within the normal range. Trolox equivalent antioxidative capacity (TEAC) decreased significantly (p < 0.001) in all groups during supplementation. MDA-TBARS remained unchanged after five weeks except for the 40 mg beta-carotene substitution group, where a significant decrease was observed (p < 0.05). CONCLUSION: Beta-carotene supplementation of healthy subjects significantly increased plasma beta-carotene status without inducing adverse biological effects. Beta-carotene did not especially protect against oxidative stress, except for the 40 mg group. These data suggest that additional effects of beta-carotene supplementation on well-nourished, healthy subjects are limited. 相似文献
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Objective
The aims were to evaluate, via multi-year student cohorts: (i) the incidence of pre-test failures and (ii) shear bond strengths of single- and multi-step adhesives to bovine dentin.Methods
The experiments were performed by cohorts of dental students (2008–2016). Each year the bond strengths of three dental adhesives to bovine dentin were tested. Four self-etching adhesives (Optibond-All-in-One, [OBAIO]; Optibond XTR [OBXTR]); Xeno V [XV]; Xeno V+ [XV+]; a three-step etch-and-rinse-system (Optibond FL, [OBFL]), a self-etch universal adhesive (Scotchbond Universal [SBU]) and a self-etch/etch-and-rinse adhesive (Xeno Select, [XS]) were included in the study. Composite-cylinders were bonded perpendicularly to prepared bovine dentin surfaces. Shear-tests were performed with a universal-testing-machine.Results
Both overall, and within years, XV and XV+ showed significantly (p < 0.01) higher percentages of pre-test failures versus other adhesive systems tested in the period 2008–2014 (OAIO, OBFL, OBXTR). Fewest pre-test failures were observed for OBFL, OBXTR and SBU. Trends in mean bond strengths and Weibull distributions were noted, per adhesive, with trends in the incidence of pre-test failures. Pre-test-failures and bond strengths depended on the air-drying technique. The adhesive systems showed variable technique sensitivity.Multistep bonding systems (Optibond FL and Optibond XTR) showed minimal pre-test failures and high bond strength applied by relatively inexperienced operators and irrespective of the applied air-drying technique. However, two single-step adhesives (OAIO and SBU) showed comparable results to the multi-step systems.Significance
The clinical need for rapid application dentine adhesives can result in varied outcomes with relatively inexperienced operators. These outcomes include both the incidence of pre-test failures as well as the distributions of shear bond strengths achieved, although these measures appear to be related. However, both outcomes are dependent upon the adhesive products utilised and especially upon the applied air pressure (flow rate). Some rapid application systems appear to perform comparably with well-established multi-step adhesives. 相似文献7.
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