Development and characterization of a novel bulk-fill elastomeric temporary restorative composite

Abstract Objectives: This study investigated the physical and mechanical properties, antibacterial effect and biocompatibility of novel elastomeric temporary resin-based filling materials (TFMs) containing zinc methacrylate (ZM). Material and Methods: Experimental TFMs were prepared by mixing the zinc methacrylate with monomer, co-monomer, photoinitiator and fillers. A ZM concentration of 0 (control), 0.5% (Z0.5); 1% (Z1), 2% (Z2), or 5% (ZM5) wt% was added to the TFMs. Fermit-N (F) was used for comparison with the experimental material. Microleakage, water sorption/solubility, degree of conversion, depth of cure, ultimate tensile strength, and hardness were determined and compared. A modified direct contact test (DCT) with Enterococcus faecalis and a Streptococcus mutans' biofilm accumulation assay was carried out to evaluate the antimicrobial effect and cytotoxicity of the assay. Statistical comparisons were performed (α=5%). Results: The results showed that the physical and mechanical properties of the experimental TFMs with ZM are comparable with the properties of the commercial reference and some properties were improved, such as lower microleakage and water sorption, and higher ultimate tensile strength values. TFMs with ZM killed E. faecalis only after 1 h. Biofilm development of S. mutans was not affected by the inclusion of ZM in the experimental TFMs. Conclusions: The present findings suggest that the physical, mechanical and biological properties of the experimental TFMs with ZM are comparable with the properties of the commercial reference. However, some properties were improved, such as lower microleakage and water sorption, and higher ultimate tensile strength values.

Two mechanisms of oral malodor inhibition by zinc ions

Abstract Objectives The aim of this study was to reveal the mechanisms by which zinc ions inhibit oral malodor. Material and Methods The direct binding of zinc ions to gaseous hydrogen sulfide (H2S) was assessed in comparison with other metal ions. Nine metal chlorides and six metal acetates were examined. To understand the strength of H2S volatilization inhibition, the minimum concentration needed to inhibit H2S volatilization was determined using serial dilution methods. Subsequently, the inhibitory activities of zinc ions on the growth of six oral bacterial strains related to volatile sulfur compound (VSC) production and three strains not related to VSC production were evaluated. Results Aqueous solutions of ZnCl2, CdCl2, CuCl2, (CH3COO)2Zn, (CH3COO)2Cd, (CH3COO)2Cu, and CH3COOAg inhibited H2S volatilization almost entirely. The strengths of H2S volatilization inhibition were in the order Ag+ > Cd2+ > Cu2+ > Zn2+. The effect of zinc ions on the growth of oral bacteria was strain-dependent. Fusobacterium nucleatum ATCC 25586 was the most sensitive, as it was suppressed by medium containing 0.001% zinc ions. Conclusions Zinc ions have an inhibitory effect on oral malodor involving the two mechanisms of direct binding with gaseous H2S and suppressing the growth of VSC-producing oral bacteria.

Impact of micronutrients supplementation on bone repair around implants: microCT and counter-torque analysis in rats

ABSTRACT The use of natural substances and micronutritional approaches has been suggested as a therapeutic alternative to benefit the bone healing associated with no side effects. Nevertheless, the influence of micronutritional interventions with therapeutic proprieties on the bone repair has yet to be intensely evaluated, and no evidence is available exploring the impact of micronutrient supplementation on the peri-implant bone healing. Objective This study investigated the effect of micronutrients supplementation on the bone repair around implants. Material and Methods One screw-shaped titanium implant was inserted in each tibia of each rat, which were assigned to: daily administration, for 30 d, of the placebo solution (Placebo group-n:18) or micronutrients supplementation (Micronutrients group-n:18), based on calcium, magnesium, zinc, and vitamin D3 intake. After, the animals were sacrificed. One of the implants was removed by applying a counter-torque force to evaluate the force to rupture the bone-implant interface. The other implant was evaluated by microcomputed tomography (CT) examination to determine the bone-to-implant contact (BIC) and the bone volume (BV/TV). Results No statistically significant differences were observed between the groups for both counter-torque values and microCT parameters (p>0.05). Conclusion Within the limits of this study, micronutrients supplementation did not provide additional benefits to the bone healing around dental implants.

Acute lower respiratory tract infection; therapeutic role of zinc in patients

ABSTRACT: Zinc is an essential rnicronutrient with catalytic role in over a hundred specific metabolic enzymes in human metabolism regulates the expression of the metallothionein gene, apoptosis and synaptic signaling and needed for many aspects of immune system. Thus the zinc 'supplementation in patients with acute lower respiratory tract infections might have potential benefits

Objectives: To evaluate the efficacy of zinc supplementation in patients with acute lower respiratory tract infections. Study design: Quasi experimental study. Setting: Study was conducted in the pediatrics department Independent hospital Faisalabad; the indoor patients meeting the inclusion criteria from 26[th] January to 25[th] July 2013 were included in study

Material and methods: 100 children meeting the inclusion criteria were included in the study which were divided into two groups with random allocation i.e. Group A [Odd number] and Group B [Even number]. Group A was given zinc supplementation 20mg of elemental zinc for 14 days. Along with antimicrobials, oxygen and antipyretics for fever while 50 children in Group B were given with antimicrobials. Oxygen and antipyretics for fever without zinc

Results: Baseline clinical parameters were comparable in both groups at admission. Outcome measures considered were duration of fever, tachypneoa, chest indrawings and total duration of hospital admission. Effect of zinc supplementation is significant with p-value of less than 0.05 for duration of tachypnoea and chest indrawings and total duration of hospital admission while result showed p-value equal to 0.05 that is just significant for duration of fever

combination of zinc and glibenclamide limits cardiovascular complications in diabetic rats via multiple mechanisms

Cardiovascular complications have become a major cause of mortality for diabetic patients. Glibenclamide is an effective hypoglycemic agent, but failed to alleviate diabetic complications. This study aimed to evaluate whether the addition of zinc to glibenclamide could mitigate such complications. Diabetes was induced using streptozotocin [60 mg/kg, i.p.]. Cardiovascular complications were detected by the significant rise of cardiac enzymes, serum lipids, myocardial oxidative stress and cardiac levels of tumor necrosis factor-alpha [TNF-alpha, a marker for inflammation] as well as massive histological changes in the heart wall in diabetic control compared to non-diabetic group. Levels of serum nitric oxide and cardiac vascular endothelial growth factor [VEGF, an angiogenic marker] were lower in diabetic rats. Addition of zinc sulfate [30mg/kg] to glibenclamide [600[micro]g/kg] resulted in significant improvement in cardiac biomarkers, oxidative status and serum lipids. Highly significant reduction in cardiac TNF-alpha [P<0.001], in addition to significant rise in nitric oxide [P<0.05] and VEGF [P<0.01] were observed. Cellular infiltration and myocardial edema were ameliorated. These results suggest that a combined treatment of zinc and glibenclamide might be a potential therapy for preventing the risk of cardiovascular complications and reducing the mortality rate among diabetic patients

Foliar application of Zn at flowering stage improves plant’s performance, yield and yield attributes of black gram.

Black gram plants subjected to varying levels of Zn supply (0.01 to 10 µM Zn) showed optimum growth and dry matter yield in plants receiving 1 µM Zn. The dry matter yield of plants decreased in plants receiving 0.01 and 0.1 µM Zn (deficient) and excess levels of Zn (2 and 10 µM Zn). The plants grown with Zn deficient supply showed delayed flowering, premature bud abscission, reduced size of anthers, pollen producing capacity, pollen viability and stigma receptivity resulting in poor pod formation and seed yield. Providing Zn as a foliar spray at pre-flowering stage minimized the severity of Zn deficiency on reproductive structure development and enhanced the seed nutritional status by enhancing seed Zn density, seed carbohydrate (sugar and starch content) and storage proteins (albumins, globulins, glutenins, and prolamines).

Effects of zinc during lactation on the junctional epithelium and inserted gum in rats / Efectos del zinc durante la lactancia sobre el epitelio de unión y la encía insertada en ratas

The purpose of this study was to evaluate the effects of zinc, during lactation, on the junctional epithelium and inserted gum of the first upper molar of rats. The study used one-day old male rats, divided into two groups: those whose mother had been treated with 300 mg zinc chloride (ZnCl2) in the drinker water (treated group), and those whose mothers did not receive ZnCl2 (control group). After 21 days, the rat pups were sacrificed. Using karyometrical techniques, the greater (D) and smaller (d) nuclear diameters of the different layers of the junctional and inserted gum epithelia were determined, and the mean geometric diameter, D/d ratio, perimeter, area, volume, volume/area ratio, eccentricity, shape coefficient, and the contour index were estimated. The 100-point Merz grid was used with the purpose of evaluating the citoplasmatic and celular volume, the nucleus/citoplasm relationship, number density, outer surface/basal layer ratio, the thickness of epithelial layers, and the surface density. The results were submitted to statistical analysis using the Wilcoxon-Mann-Whitney test. The nuclei of the studied structures were significantly smaller, and the stereological results demonstrated that there were smaller cells, hence meaning a greater number of cells per mm3 of tissue, in the treated group. Zinc caused changes on the studied epitheliums, according to morphometric and stereological evaluations.

El objetivo de este estudio fue evaluar los efectos del zinc durante la lactancia, sobre el epitelio de unión y la encía insertada del primer molar superior de ratas. Fueron utilizadas ratas macho de un día de edad, divididas en dos grupos: aquellas cuyas madres habían sido tratadas con 300 mg de cloruro de zinc (ZnCl2) con agua del bebedero (grupo tratado) y aquellas cuyas madres no recibieron ZnCl2 (grupo control). Las crías fueron sacrificadas después de 21 días. Utilizando técnicas cariométricas fueron medidos los diámetros mayor (D) y menor (d) de los núcleos de las células de los diferentes estratos del epitelio de unión y de la encía insertada, estimándose el diámetro geométrico medio, la relación D/d, perímetro, área, volumen, relación volumen/área, excentricidad, coeficiente de forma e índice de contorno. Fue usada la rejilla de Merz, de 100 puntos, con la finalidad de evaluar el volumen celular y citoplasmático, la relación núcleo/citoplasma, densidad numérica, relación superficie externa/superficie basal, espesor de las capas epiteliales y densidad de superficie. Los resultados fueron sometidos a análisis estadístico mediante el test de Wilcoxon-Mann-Whitney. En el grupo tratado los núcleos celulares de las estructuras estudiadas fueron significativamente menores y los resultados estereológicos demostraron que las células eran menores, por lo tanto, con mayor número por mm3 de tejido. De acuerdo a los resultados morfométricos y estereológicos, el zinc provocó cambios en los epitelios estudiados.

Catecholamine contents of different region of adult rat brain are altered following short and long-term exposures to Pb[+2]

Catecholamine is a group of neurotransmitters that is believed to be responsible for the normal function of animal brain. Physiological and behavioral changes of human body have been reported due to the damage of the brain function following lead exposure. Due to the assumption of lead disposal in brain tissue with two year for its half-life, which results in alteration of brain function, we investigated the ability of lead to change the brain catecholamines during short and long-term studies. Rats were exposed daily with varying amounts of lead and catecholamine contents of cerebellum, mid-brain and brain cortex were determined. Acute peritoneal administration of single dose of lead as lead acetate [260 micro mol/Kg] after 2 h reduced [p < 0.05] the catecholamine levels of cerebellum, mid-brain and cortex part by 34.9%, 35.44% and 23.8%, respectively. The extension of experiment time to 5 h, significant [p < 0.05] reductions in catecholamine levels of mentioned regions of brain by 32.35%, 12.35% and 19.3% were seen respectively. Daily intraperitoneal administration of 10 micro mol/Kg lead for 30 and 60 days reduced catecholamines levels of cerebellum [22.22% and 30.44%], midbrain [12.48% and 26.27%] and brain cortex [11.58% and 26.7%] respectively. It might be concluded that brain dysfunction in lead intoxicated rat occurred through the reduction in the catecholamine levels of different parts of brain. Lead might be therefore considered as a probable factor in causing neurological disease in lead exposed man

Zinc y desnutrición / Zinc and undernutrition

Son cuatro los nutrientes en que su deficiencia es importante en niños: hierro, yodo, vitamina A y zinc. Más o menos se calcula que hay 2 billones de personas en el mundo con algún grado de déficit de zinc. Los pacientes que están en riesgo de presentar deficiencias de zinc son los recién nacidos con bajo peso al nacimiento, bien sea prematuros, desnutridos in útero o hijos de madres desnutridas, en los cuales sus depósitos están reducidos. A diferencia de otros oligoelementos o micronutrientes, determinar el estado de déficit no es fácil. Los niveles séricos de zinc, están influenciados por factores no dietarios como infección, estrés o actividad física extenuante; al igual que por el ciclo circadiano.

Four nutrient deficiency that is important in children, iron, iodine, vitamin A and zinc. More or less it is estimated that 2 billion people in the world with some degree of zinc deficiency. Patients who are at risk for zinc deficiency are infants with low birth weight, either premature or malnourished in utero, undernourished mothers, in which their deposits are reduced. Unlike other trace elements or micronutrients, determine the deficit is not easy. Serum levels of zinc are not influenced by dietary factors such as infection, stress or strenuous physical activity, as well as by the circadian cycle.

[ effects of dietary supplementation with zinc, magnesium and zinc plus magnesium on muscle strength in active women]

The purpose of this study was to determine the effect of dietary supplementation with zinc, magnesium and zinc plus magnesium on muscle strength in active women. Forty active women selected randomly were randomly divided into 4 groups of 10 each, all undergonig resistance training and receiving, daily, a supplement of either zinc [50 mg zinc sulfate], magnesium [250 mg magnesium oxide], or zinc plus magnesium [50 mg zinc sulfate plus 250 mg magnesium oxide], or no supplement [control group]. All the subjects had a history of sports activity. Blood samples were collected and 1-RM was measured at the beginning and after 8weeks. Independent and paired-sample t-test showed that zinc, magnesium and zinc plus magnesium supplements had no statistically significant effects on the strength of lower body muscles. However, the magnesium supplement had a significant positive effect on the strength of upper body muscles [chest, back, as well as back and hand bending muscles]. In addition, the zinc and zinc plus magnesium supplements affected significantly the strength of the back and hand bending muscles. Further analysis of the data showed that the zinc plus magnesium supplement had no significant effect on the serum zinc and magnesium concentrations. Dietary supplementation with zinc, magnesium and zinc plus magnesium can effect desirably the upper body muscles strength in active women

Inhibitory effect of zinc, copper and selenium on telomerase activity in tumor tissues and t47d breast cancer cell line

The present study was performed to investigate the effects of trace elements particularity Se, Zn and Cu on tumor genesis in breast cancer. The inhibitory effect of Se, Zn and Cu, on telomerase activity was analyzed in human breast tumor tissues and breast cancer [T47D] cells. Tissue specimens from 24 women with benign breast disease and 32 women with breast cancer specimens [ductal carcinoma, lobular carcinoma] were collected during surgery. In addition venous blood samples were obtained for assessing the trace elements. T47D cell line was cultured and treated with trace elements. Telomerase activity then was measured with TRAP assay in cell line and tissue extracts. There was a significant difference between tissue and serum levels of Cu, Se and the ratio of Cu/Zn in patients and controls [P<0.001]. After treating with 100 microm/L Zn So4, 10 um /L Cu So4 for 6 hours, telomerase activity of T47D cells was markedly increased. But after treating with 10, and 30 um /L selenium-L- methionin, telomerase activity was markedly inhibited. Telomerase activity of T47D cells for 24 hours were 0.93, 0.60 and for 48 hours were 0.76, 0.12 respectively [control 49.2%]. There were variations in serum level of Zn and Cu in breast cancer patients. Association between trace elements level and telomerase activity level can be exploited as prognostic and diagnostic marker for breast cancer

Zinc en la infancia: rompiendo paradigmas / Zinc in childhood: breaking paradigms

El zinc es un ejemplo de un micronutriente esencial, cuya deficiencia juega un papelimportante en la comprensión de las altas tasas de mortalidad y morbilidad infantil en países en desarrollo. Tanto la deficiencia intermedia de zinc como de vitamina A, pueden pasar inadvertidas clínicamente. Con respecto a la inmunidad, el zinc es fundamental para las funciones de tejidos de alto recambio, especialmente en el sistema inmunitario, y su deficiencia se asocia a alteraciones de la inmunidad innata, la inmunidad humoral y la inmunidad celular. Existe evidencia que avala la s u p l eme n t a c i o n d e z i n c d u r a n t e e inmediatamente después de un episodio de diarrea aguda, con lo que se disminuye su tiempo de duración y la gravedad, con reducción en la incidencia de diarrea en los dos o tres meses siguientes.Aun no se conoce exactamente cuál es el mecanismo que explique por qué se encuentra limitada la proliferación celular ante la deficiencia de zinc.

Zinc is an example of an essential micronutrient whose deficiency plays an important role in understanding the high rates of infant mortality and morbidity in developing countries. Both intermediate zinc deficiency and vitamin A, may go unnoticed clinically.With respect to immunity, zinc is essential for the functions of tissues of high turnover, especially in the immune system, and its deficiency is associated with alterations of innate immunity, humoral immunity and cellular immunity. There is evidence supporting zinc supplementation during and immediately after an episode of acute diarrhea, which shortens their duration and severity, with a reduction in the incidence of diarrhea in the two or three months. Still not known exactly what the mechanism that explains why it is limited to cell proliferation in zinc deficiency.

Protective effect of zinc over lead toxicity on testes

To determine the effects of lead and zinc on testes. Randomized control trial. Basic Medical Sciences Institute, Jinnah Postgraduate Medical Centre, Karachi, from August 2003 to December 2005. Sixty adult [90 days old] albino rats were obtained from animal house JPMC for the study and divided into 3 groups. Group A received injection normal saline 1 cc intraperitoneally daily for 8 weeks. Group B received lead chloride in a dose of 10 mg/kg body weight intraperitoneally daily. Group C received zinc chloride in a dose of 1 mg/kg body weight before half an hour of injection of lead chloride in a dose of 10 mg/kg body weight intraperitoneally daily so that to provide pre-treatment. On the day of completion of treatment the animals were sacrificed testes removed and fixed in Bouins fluid. Testes were dehydrated in the ascending strength of alcohol, 5 micro m thick sections were cut and stained with PAS Iron Hematoxylin. Student's t-test was used for statistical analysis with significance at p<0.05. The mean diameter of seminiferous tubule was 291.91 +/- 1.18, 198.53 +/- 1.67 and 288.77 +/- 1.11 micro m in groups A, B and C respectively. Diameter of seminiferous tubules decreased by 31.99% in group B [p<0.001; CI 89.023 to 97.736] as compared group A and while group B comparing with group C, the diameter of seminiferous tubules was decreased by 31.25% [p-value=0.076; CI-94.264 to-86.203]. Mean thickness of germinal epithelium was 96.19 +/- 1.01, 50.69 +/- 1.20 and 94.94 +/- 0.54 micro m in groups A, B and C respectively. Thickness of germinal epithelium decreased by 47.30 in group B [P<0.001; CI 42.503 to 48.496] as compared to group A and while comparing group B with group C, the thickness of germinal epithelium was decreased by 46.61% [p=-44.25; CI-46.704 to-41.787]. Zinc prevented toxic effects of lead on germinal epithelium in the albino rats

Infl uenza a virus induced apoptosis: Inhibition of DNA laddering & caspase-3 activity by zinc supplementation in cultured HeLa cells.

Background & objectives: The pathogenesis of infl uenza virus infection involves virus replication in epithelial cells of the respiratory tract and the consequent degeneration of infected cells. Infl uenza virus induces cellular degeneration following infection of cultured cells in vitro, and the cytopathic effect (CPE) occurs principally through apoptotic cell death. This study was undertaken to fi nd out the effect of zinc on infl uenza virus induced apoptosis in cultured HeLa cells. Methods: The sub-confl uent monolayer HeLa cells were used to study the effect of zinc on infl uenza virus induced apoptosis. The apoptotic markers viz., caspase-3 activity, phagocytic index, morphological changes, and DNA fragmentation were assayed. Results: When HeLa cells were infected with a cell adapted pathogenic strain of infl uenza A (A/Udorn/ 317/72H3N2) virus, DNA fragmentation was observed in virus infected cells by 24 h post infection and caspase-3 activity was maximum at 4 h post infection after which it reached to plateau. Treatment of cells with 0.1 5mM concentration of zinc till 8 h post infection inhibited DNA fragmentation and also caspase 3 activity was decreased signifi cantly up to 2 h post infection. Interpretation & conclusions: When the infected HeLa cells were incubated with adherent macrophages, effi cient phagocytosis occurred and the release of virus into the culture medium was inhibited. These results suggested that inhibitory effect on infl uenza virus induced apoptotic death of cultured cells can be determined at an early stage of the infection by treatment of zinc.

Hormesis response of marine and freshwater luminescent bacteria to metal exposure

The stimulatory effect of low concentrations of toxic chemicals on organismal metabolism, referred to as hormesis, has been found to be common in the widely used luminescence bioassay. This paper aims to study the hormesis phenomenon in both marine and freshwater luminescent bacteria, named Photobacterium phosphorem and Vibrio qinghaiensis. The effects of Cu (II), Zn (II), Cd (II) and Cr (VI) on luminescence of these two bacteria were studied for 0 to 75 minutes exposure by establishing dose- and time-response curves. A clear hormesis phenomenon was observed in all four testing metals at low concentrations under the condition of luminescence assays.

Beneficial effect of modified egg on serum T3, T4 and dyslipidaemia following dietary Zn-supplementation in Wistar rat.

A fall in serum T3 and T4 along with increase in serum cholesterol, triglycerides, LDL-c and VLDL-c and decrease in HDL-c was observed in albino Wistar rats when fed on semi-synthetic diet containing either 40 or 80mg Zn/kg diet. Zn concentrations were observed to increase with decreased concentration of Cu and Mg in their tissues. On including modified egg (Indian Patent Application No. 2264\Del\2005) in the Zn supplement diet, the levels of T3 and T4, lipid profile in serum and mineral status approached closer to control group-I. The data suggest that hypothyroidism and dyslipidaemia caused by excessive Zn in diet can be ameliorated on consuming these modified eggs due to restoration of mineral status in the body.

Effect of monothiol along with antioxidant against mercury-induced oxidative stress in rat.

Efficacy of thiol chelators viz. N-acetyl cysteine and D-penicillamine (NAC and DPA) along with nutritional supplements viz. zinc acetate, sodium selenite and magnesium sulphate (Zn, Se and Mg) in the treatment of mercury intoxication was investigated in rats. This is of particular interest since high bonding affinity between mercuric ion and the thiol group exits. The mutual antagonism of mercury and selenium is one of the strongest examples of the interaction in the trace element field. Adult rats of Sprague-Dawley strain were administered a bolus dose of dimethyl mercury (10 mg/kg) orally. A significant rise in the aspartate aminotransferase, alanine aminotransferase, serum alkaline phosphatase, lactate dehydrogenase, gamma glutamyltranspeptidase, bilirubin and creatinine were observed. Single mercury exposure also resulted in a significant increase in lipid peroxides with a concomitant decrease in reduced glutathione level in liver, kidney and brain. A decrease in the enzymatic activities of acetyl cholinesterase in different regions of the brain was observed. These parameters were restored considerably with chelating agents along with nutritional supplementation, but NAC+Se and DPA+Mg offered significant protection in comparison with other combinations.