Effects of Fluoride Release on Enamel Color Alteration

The aim of this study is to evaluate teeth discoloration after the usage of adhesive fluoride release. Material and Method: 80 extracted healthy premolars divided into two groups were used in the study, with metal brackets being bonded in both groups,. The first group universal adhesive was applied (transbond light cure adhesive paste-Transbond XT), whereas in the second group fluoride releasing bonding material was used (opal bond MV composite and opal seal). The measurement of color parameters was performed using the spectrophotometer vita easyshade 4.0 to calculate ΔL, Δa, Δb, and ΔE. Statistical Analysis: 3-way mixed analysis of variances (ANOVA) was used to compare ΔE before using adhesive material and after the procedure. On the other hand, it was used to compare Δa, Δb, and ΔL before and after using adhesive material. The statistical significance level was established at P< 0.05. Boferroni correction was used to create mean differences between the results. Results: The result of this study showed that ΔE* values were increased in all groups. The mean difference of ΔE* value in the first group (3M adhesive material) was 2.54± 1.57. At the same time, the ΔE value in opal adhesive group was 4.43±5.4. These results showed that fluoride seal had direct effect on enamel color after a period of three months teeth storage. Results showed above the normal limit and produced visible color change on the surface of the teeth after finishing procedure. On the other hand, ΔL values were increased in both groups, with a significant difference in the first group (p value 0.04) and with no significant difference in the second group (p value 0.239). Conclusion: The highest color changes were observed after the finishing procedure in opal bond MV composites and the opal seal groups. This was done by increasing ΔE value due to the presence of fluoride release adhesive structure. Transbond light cure adhesive past-Transbond XT had acceptable clinical change after the debonding and finishing procedure by increasing ΔE value

Effect of Curcumin on Oxidative Stress in a Model of Turpentine Induced Acute Experimental Inflammation

Curcumin, a natural phenolic compound is an anti-tumor agent with anti-inflammatory and anti-oxidant properties. The aim of this research was to evaluate oxidative stress levels, the antioxidant activity and Curcumin concentrations by high performance liquid chromatography (HPLC) in an acute experimental inflammation induced by Turpentine oil (intramuscular 0.6 mg kg-1 body weight) and to compare a prophylactic versus a therapeutic regimen of Curcumin (oral suspension of 150 mg Curcumin kg-1 rat weight). Sixteen adult male Wistar rats were assigned to four groups: Control, Group I (Curcumin only), Group II (Curcumin administration, then induced inflammation after 1 hour) and Group III (induced inflammation then Curcumin administration after 2 hours). Oxidative stress was assessed by measuring serum malondialdehide and carbonylated proteins, while systemic and local total antioxidant capacity was determined by ABTS. Local tissue changes (muscle, kidney, liver) were analysed using histopathology. Results showed that acute inflammation significantly increased lipid peroxidation in Groups II and III compared to Control and Group I. A significantly reduced total antioxidant capacity (ATBS) was present in serum and kidney in Group II, also in muscle and kidney in Group III. ABTS levels were significantly increased only in the liver tissue of the animals in Groups II and III with induced inflammation as compared to Group I. This study proved the potential of Curcumin in reducing oxidative stress in both prophylactic and therapeutic regimens

Obtaining and Characterizing Alginate/k-Carrageenan Hydrogel Cross-Linked with Adipic Dihydrazide

The aim of this paper is obtaining and characterizing hydrogels based on different ratios of oxidized alginate (oA) and k-carrageenan (C), chemically cross-linked with adipic dihydrazide (adh). The alginate (A) was first oxidized with sodium metaperiodate in order to transform it into the dialdehyde derivative, a more reactive compound than alginate. A known procedure for oxidation of alginate with sodium metaperiodate in ethanol-water in order to improve alginate reactivity by transforming the hydroxyl end-groups into dialdehyde was used, preceded by a partially cleavage of the alginate chains. In the second stage, the mixture of dialdehydic derivative of oxidized alginate, k-carrageenan and glycerol subjected to reaction with adipic dihydrazide leads to a Semi-Interpenetrated Network covalently cross-linked alginate/k-carrageenan hydrogel (oACadh), based on the dihydrazone compound which is responsible for the chemical cross-linking. Pure alginate, k-carrageenan, oxidized alginate, adipic dihydrazide and the cross-linked hydrogel were characterized by: FTIR, XRD, and SEM

The Study of Nutraceutical Effects of the Whey Zonar and of Lyophilized Concentrate Obtained from Zonar in C26 Colon Carcinoma Grafted Subcutaneously in Balb/C Mice

This paper investigates the nutraceutical properties of the whey Zonar and of lyophilized concentrate obtained from Zonar in C26 tumor bearing BALB/C mice. The experiment was conducted on 30 female mice, divided into 6 groups (n=5). Groups 4, 5 and 6 were injected subcutaneously with 1*106 C26 carcinoma cells. Groups 2,3, 5 and 6 received a diet based on Zonar products. The evolution of body mass and tumor volume was assessed weekly. At the end of the 21-day study, blood samples for hematological, biochemical and oxidative stress analysis were drawn and tumor tissue samples were collected for histopathological examination. After 21 days, a significant in vivo reduction of the tumor volume in groups 5 and 6 was recorded. The biochemical analysis showed Zonar's protective muscular effects, due to decreases of the creatine-kinase level in groups 5 and 6. Further investigations revealed an increased level of glutathione in all groups which received Zonar, eliciting its antioxidant potential. Histopathologically, increased necrotic areas highlighted the anti-tumoral effect of the synergism between Zonar and the lyophilized concentrate. The results of this experiment implies that whey Zonar & the lyophilized whey prevents tumor cachexia, as well as other cancer associated adverse effects

Microstructure and Mechanical Behavior of Modern Universal-Chromatic and Bulk-Fill Resin-Based Composites Developed to Simplify Dental Restorative Procedures

One of the recent trends in the development of resin-based composites (RBCs) focuses on universal coloring to avoid time-consuming color matching and RBC layering for a clinically appropriate esthetic impact. We evaluated an experimental material for posterior restorations combining universal coloring with the possibility of bulk-fill placement. Clinically established materials were analyzed as a reference, including a bulk-fill and a universal chromatic RBC. Microstructural features were described using scanning electron microscopy and related to macroscopic and microscopic mechanical behavior. Standards to be met before market launch were supplemented by fractography, Weibull analysis, and aging behavior assessment. Quasi-static and viscoelastic behavior were evaluated on a microscopic scale, incorporating a large number of parameters and increasingly aggressive immersion media. All materials complied with the standard requirements even after aging. The latter had little impact on the measured parameters, except for strength. Strength, modulus of elasticity, and hardness parameters on the one hand and damping behavior on the other were mutually exclusive. Despite considerable differences in the microstructure and type of filler, an increased filler amount remained critical for better mechanical properties. The lower proportion of inorganic fillers was directly transferred to the elastic modulus values, which, in turn, restricts the experimental material in its clinical applications to smaller occlusal fillings

New Composite Hydrogel Based on Whey and Gelatin Crosslinked with Copper Sulphate

By-products from the meat and dairy industries are important sources of high biological value proteins. This paper explores possibilities for improving the swelling and integrity of a cross-linked whey and gelatin hydrogel with different amounts of CuSO4 × 5H2O. Overall, swelling tests demonstrate that cross-linked samples show a better hydration capacity and stability in the hydration medium, but different copper concentrations lead to different swelling behavior. At concentrations smaller than 0.39%, the sample lasts for 75 h in a water environment before beginning to disintegrate. At a concentration of copper sulphate higher than 0.55%, the stability of the sample increased substantially. The swelling kinetics has been investigated. The diffusion constant values increased with the increase in copper concentration, but, at the highest concentration of copper (0.86%), its value has decreased. Spectroscopy analyses such as Fourier transform infrared (FT-IR), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-VIS), and nuclear magnetic resonance (NMR) relaxometry analyses revealed changes in the secondary and tertiary structure of proteins as a result of the interaction of Cu2+ ions with functional groups of protein chains. In addition to its cross-linking ability, CuSO4 × 5H2O has also shown excellent antibacterial properties over common bacterial strains responsible for food spoilage. The result of this research demonstrates the potential of this hydrogel system as a unique material for food packaging