-
1.
Trace Element Levels and Oxidant/Antioxidant Status in Patients with Alcohol Abuse.
Saribal, D, Hocaoglu-Emre, FS, Karaman, F, Mırsal, H, Akyolcu, MC
Biological trace element research. 2020;(1):7-13
Abstract
Alcohol abuse is a well-known cause of imbalance in trace element levels and oxidant/antioxidant status of individuals with long time consumption. However, the levels of these parameters in the patients on the early stages of alcohol dependence without liver damage differ on various studies. The aim of our study was to measure the levels of trace elements in the serum and oxidative/antioxidative system members in the red blood cells (RBC) of early-stage alcoholic individuals and compare with control subjects. Our study included 21 male patients recently hospitalized for alcohol abuse and 25 healthy non-abusing male controls. Levels of Fe, Zn, and Cu in the serum and MDA, SOD, CAT, and GSH in the red blood cells (RBC) of the subjects were measured. Fe, Zn, and Cu levels were lower in the study group when compared to the controls. Levels of lipid peroxidation marker MDA was high, whereas the activities of antioxidant enzymes SOD and CAT were decreased in our study group. However, levels of GSH, an antioxidant compound were higher in the alcohol abuse group. RBC SOD levels were positively correlated with Fe, Cu, Zn, and CAT. There was a positive correlation between Fe-Cu, Zn-Fe, Zn-Cu, CAT-Zn, and CAT-SOD. MDA was negatively correlated with Fe, Zn, SOD, and CAT. The results obtained from present study indicate that high levels of alcohol intake are related with increased oxidative damage and decreased levels of antioxidant enzymes and trace elements. Additionally, antioxidant compensation mechanisms are still on process in the early stages of chronic alcohol exposure.
-
2.
The effect of regular exercise and massage on oxidant and antioxidant parameters.
Karabulut, AB, Kafkas, ME, Kafkas, AS, Onal, Y, Kiran, TR
Indian journal of physiology and pharmacology. 2013;(4):378-83
Abstract
This experimental study aimed to determine the effects of the combined application of regular exercises and massage on the values of Malondialdehyde (MDA), Nitric Oxide (NOx), Glutathione (GSH), Adenosine Deaminase (ADA) and Superoxide Dismutase (SOD). Twenty five sedentary women (32-50 years) who did not have the habit of getting regularly massages or exercising and participated voluntarily in the study. The subjects were randomly separated into three groups: control group (CG, n = 9), exercise group (EG, n = 8), and massage and exercise group (MEG, n = 8). The basic result of this study was that a statistically significant decrease was observed in the post-test MDA values of both EG and MEG subjects. Moreover, when the GSH and SOD values are compared to CG, a statistically significant increase was determined in the values of both EG and MEG. As a result, the findings show that regular physical activities and massage manipulations significantly decrease MDA, increase SOD and GSH activities, and result in no change in NOx and ADA activities supports the assumption that regular physical activity has positive health effects.
-
3.
Effect of bleaching protocols with 38% hydrogen peroxide and post-bleaching times on dentin bond strength.
Souza-Gabriel, AE, Vitussi, LO, Milani, C, Alfredo, E, Messias, DC, Silva-Sousa, YT
Brazilian dental journal. 2011;(4):317-21
Abstract
This study assessed the effect of bleaching protocols with 38% hydrogen peroxide (HP) and post-bleaching times on shear bond strength of a composite resin to dentin. One-hundred slabs of intracoronary dentin were included and randomly assigned into 2 groups according to the bleaching protocol: HP (2 applications of 10 min each) and HP activated by LED laser (2 applications of 10 min each/45 s of light activation). Groups were subdivided according to the post-bleaching time (n=10): 1 day, 3 days, 7 days, 10 days and 14 days. The control group was unbleached and restored (n=10). The specimens were restored with Single Bond adhesive system/Filtek Z250 resin using a polytetrafluorethylene matrix and were submitted to the shear bond strength testa after 24 h,. Data were analyzed by ANOVA and Tukey's test (α=0.05). Unbleached group (0.283 ± 0.134) had the highest bond strength and was statistically similar (p>0.05) to HP/10 days (0.278 ± 0.064), HP + LED laser/10 days (0.280 ± 0.078), HP/14 days (0.281 ± 0.104), HP + LED laser/14 days (0.277 ± 0.093). Lower bond strength were verified in HP/1 day (0.082 ± 0.012), HP/3 days (0.079 ± 0.013), HP + LED laser/1 day (0.073 ± 0.018) and HP + LED laser/3 days (0.080 ± 0.015), which were statistically similar (p>0.05). HP/7 days (0.184 ± 0.154) and HP + LED laser/7 days (0.169 ± 0.102) had intermediate values (p<0.05). The restorative procedure of intracoronary dentin bleached with 38% HP with or without the use of light source should be performed after at least 10 days after the bleaching treatment.
-
4.
The use of atomic force microscopy in determining the stiffness and adhesion force of human dentin after exposure to bleaching agents.
Forner, L, Salmerón-Sánchez, M, Palomares, M, Llena, C, Amengual, J
Journal of endodontics. 2009;(10):1384-6
Abstract
INTRODUCTION Oxidant bleaching agents may induce several alterations on mineralized teeth tissues. Our aim is to study, at the ultrastructural level, mechanical modifications induced on dentin after exposure to different bleaching agents. METHODS Nanoindentation performed with atomic force microscopy was used to measure changes in dentin stiffness as well as the adhesion force between the tip and the tissue both in intertubular and peritubular dentin. For each specimen, dentin localization, and bleaching agent, 100 independent nanoindentations were performed. Carbamide peroxide (30%) and hydrogen peroxide (35%) were used as bleaching agents. RESULTS A significant reduction of both stiffness and adhesion force was found for both carbamide and hydrogen peroxide in peritubular and intertubular dentin. CONCLUSIONS The use of bleaching agents led to a significant reduction in dentin local (at the nanoscale) mechanical properties.
-
5.
The effect of tooth bleaching on the enamel surface and the tensile force to debond orthodontic brackets.
Mishima, FD, Valentim, RG, Araújo, MT, Ruellas, AC, Sant'Anna, EF
Journal of orthodontics. 2009;(4):236-42
Abstract
OBJECTIVE The aim of this study was to evaluate the influence of successive tooth bleaching on the tensile force to debond orthodontic brackets and dental enamel. DESIGN In vitro study. SETTINGS Department of Orthodontics, Faculty of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. MATERIALS AND METHODS Seventy-two human premolars were divided into three groups: Group 1 was not submitted to bleaching, Group 2 was subjected to one tooth bleaching (35% hydrogen peroxide enabled by LEDs) and Group 3 was subjected to two tooth bleachings interspersed by aging. Twenty teeth from each group were subjected to tensile test, failure pattern after debonding and evaluation of resin/enamel interface. Four teeth from each group were not submitted to tensile bond testing and had their external surfaces and internal structure analyzed by SEM and polarized light microscopy. RESULTS The strength of the brackets decreased in Groups 2 and 3, but was not significant (P=0.635). In general, the failure pattern appeared at the resin/bracket interface or within the resin. The experimental groups showed an increase in slots and erosions on the surface of the enamel and were more pronounced in Group 3. There were no changes to the internal structure of the enamel. CONCLUSIONS The use of a 35% hydrogen peroxide in-office bleaching system, in vitro, seven days before bonding, does not significantly reduce the tensile force to debond orthodontic brackets, even after a second bleaching procedure. In most cases, debonding occurred at the adhesive/bracket interface or within the adhesive. Bleaching alters the enamel surface and the resin/enamel interface, but it does not influence bond strength.
-
6.
Effect of curing lights and bleaching agents on physical properties of a hybrid composite resin.
Lima, DA, De Alexandre, RS, Martins, AC, Aguiar, FH, Ambrosano, GM, Lovadino, JR
Journal of esthetic and restorative dentistry : official publication of the American Academy of Esthetic Dentistry ... [et al.]. 2008;(4):266-73; discussion 274-5
Abstract
UNLABELLED The aim of this in vitro study was to evaluate the microhardness (MH) and diametral tensile strength (DTS) of a minifill hybrid composite (Filtek Z250, 3M ESPE), polymerized with halogen lamp or second generation light-emitting diode (LED), submitted to different bleaching agents. Composite resin specimens were randomly polymerized according to experimental groups (halogen, 550 mW/cm(2)/20 seconds; LED, 550 mW/cm(2)/25 seconds) and subdivided into three subgroups (N=8): A, without bleaching (control); H, 35% hydrogen peroxide; and C, 16% carbamide peroxide. After that, the MH test and DTS test were performed. Two-way analysis of variance (whitening x light) and Tukey's tests (alpha=5%) were performed. For DTS, there were no statistical differences among the bleaching agents and the control group; however, the halogen group presented statistically lower DTS (p<0.05) than the LED group. For the MH test, the carbamide peroxide group presented statistically lower MH means (p<0.05) than the control groups, and there were no statistical differences among the light-curing units. Sixteen percent carbamide peroxide reduced the MH of the hybrid composite tested. The second generation LED presented a performance similar to or better than the halogen lamp for hardness and DTS, respectively. CLINICAL SIGNIFICANCE Repolishing of minifill hybrid composite is suggested, as the alteration caused after the contact with 16% carbamide peroxide was limited to the material surface. The second generation light-emitting diode is a good option for a curing light device when the polymerization initiator of composite resin is camphorquinone.
-
7.
Clinical trial of tooth whitening with 6% hydrogen peroxide whitening strips and two whitening dentifrices.
Yudhira, R, Peumans, M, Barker, ML, Gerlach, RW
American journal of dentistry. 2007;:32A-36A
Abstract
PURPOSE To compare tooth whitening with 6% hydrogen peroxide whitening strips and two whitening dentifrices in a 12-week randomized controlled trial at a Belgian dental school. METHODS After informed consent, 46 healthy adults were randomly assigned to one of three strip + dentifrice treatment groups. Subjects received either 6% hydrogen peroxide whitening strips (Crest Whitestrips) and an anticavity toothpaste (Crest Cavity Protection), placebo strips and a sodium fluoride (NaF) whitening dentifrice (Mentadent Whitening Toothpaste) or placebo strips and a sodium monofluorophosphate (MFP) whitening dentifrice (Rembrandt Low Abrasion Whitening Toothpaste). Strip use (peroxide or placebo) was for 30 minutes, twice daily for 2 weeks, while dentifrice use was at least twice daily for 12 weeks. Efficacy was measured from standardized digital images of the maxillary facial tooth surfaces, while safety was evaluated from oral examination and interview. Treatments were compared after 2 weeks (strip use) and 12 weeks (dentifrice use) using analysis of covariance. RESULTS All subjects completed the 12-week evaluation. Adjusting for baseline and age, the peroxide strip group had -2.45 Deltab*, 2.39 DeltaL*, and -0.96 Deltaa* at Week 2. Between-group comparisons demonstrated significant (P< 0.0001) reductions in yellowness and redness, and increased brightness favoring the peroxide strip group. The peroxide strip group demonstrated 95%+ color retention (Deltab* & DeltaL*) at Week 12, differing significantly (P< 0.0001) versus either of the continuously used whitening dentifrices. There were no significant (P> 0.18) differences between the whitening dentifrice groups at any timepoints. All treatments were well-tolerated, with minor tooth sensitivity and oral irritation representing the most common findings.
-
8.
Ca2+ but not H2O2 modulates GRE-element activation by the human mineralocorticoid receptor in HEK cells.
Pfau, A, Grossmann, C, Freudinger, R, Mildenberger, S, Benesic, A, Gekle, M
Molecular and cellular endocrinology. 2007;(1-2):35-43
Abstract
The mineralocorticcoid receptor (MR) plays an important role in salt and water homeostasis as well as during cardiovascular and renal fibrosis but little is known regarding its modulation by other signaling pathways. To investigate a possible modulation under controlled conditions we used human embryonic kidney (HEK) cells (devoid of endogenous MR) transfected with the human MR and measured transactivation with a GRE-SEAP-reporter construct. MR was compared to the glucocorticoid receptor (GR) as well as to MR lacking the N-terminal domains AB (MR(CDEF)). Chelation of cytosolic Ca2+ enhanced MR activity and SGK1-expression, whereas elevation of cytosolic Ca2+ with ionomycin or thapsigargin reduced MR activity. GR activity was not affected by ionomycin or thapsigargin. MR(CDEF) activity was not affected by chelation or elevation of cytosolic Ca2+. Inhibition of ERK1/2 activation by U0126 or activation of PKA by cAMP, previously shown to modulate MR and GR activity, did not affect MR(CDEF) activity either. H2O2<500micromol/l did not affect basal nor hormone-induced reporter activity. Higher concentrations exerted the same relative inhibitory effect on GRE-SEAP-activity under basal conditions as in the presence of aldosterone-stimulated MR and elicited cytotoxic effects. Our data indicate that the genomic function of MR can be modulated by cytosolic Ca2+, PKA and ERK1/2 via an interaction with the AB-domain. H2O2 seems not to affect relative MR activity directly under our experimental conditions.
-
9.
Shear bond strength of resin composite to enamel and dentin submitted to a carbamide peroxide dentifrice.
da Silva, BM, Flório, FM, Basting, RT
American journal of dentistry. 2007;(5):319-23
Abstract
PURPOSE To assess the shear bond strength of resin composite to human enamel and dentin after using a whitening dentifrice containing carbamide peroxide for 21 days. METHODS Thirty enamel and 30 dentin slabs were embedded, flattened and randomly divided into three groups (n=10) that received different treatments: carbamide peroxide containing dentifrice (Rembrandt Plus), fluoride containing dentifrice (Close Up with fluoride), and immersion in artificial saliva as the control group. Applications were made for a 15-minute period daily, immersing the slabs in a suspension with distilled water and dentifrice in the ratio of 3:1 (weight) for 21 days. For the rest of the time, the slabs were kept in an artificial saliva solution. After the last application, an adhesive system (Single Bond) was used to bond resin-based composite cylinders (Z100) to the enamel and dentin surfaces for the shear bond strength tests. These tests were carried out in a universal testing machine at a speed of 0.5 mm/minute. RESULTS ANOVA and the Tukey test for enamel and Kruskal-Wallis and the Dunn Method for dentin, showed significant differences between slabs treated with Rembrandt Plus (REM) and the artificial saliva control group, with higher values for REM (P < 0.05). There were no differences in mean bond strengths of enamel and dentin treated with Close Up with fluoride (CLO) and REM, nor were any differences shown between CLO and the artificial saliva control group. A whitening dentifrice containing carbamide peroxide increased the bond strength of restorative systems.
-
10.
Effects of conditioners on microshear bond strength to enamel after carbamide peroxide bleaching and/or casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) treatment.
Adebayo, OA, Burrow, MF, Tyas, MJ
Journal of dentistry. 2007;(11):862-70
Abstract
OBJECTIVES To evaluate (a) the enamel microshear bond strength (MSBS) of a universal adhesive and (b) the effects of conditioning with a self-etching primer adhesive with/without prior bleaching and/or casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) application. METHODS Thirty-five molars were cut into four sections, assigned randomly to four groups (no treatment; 16% carbamide peroxide bleaching; CPP-ACP-containing paste (Tooth Mousse, TM); bleaching and TM) and treated accordingly. Specimens were divided into two for bonding with either a self-etching primer (Clearfil SE Bond, CSE) or a total-etch adhesive (Single Bond, SB). Specimens for CSE bonding were subdivided for one of four preconditioning treatments (no conditioning; 30-40% phosphoric acid (PA); 15% EDTA; 20% polyacrylic acid conditioner (Cavity conditioner, CC) and treated. The adhesives were applied and resin composite bonded to the enamel using microtubes (internal diameter 0.75mm). Bonds were stressed in shear until failure, mean MSBS calculated and data analysed using ANOVA with Tukey's HSD test (alpha=0.05). The modes of bond failure were assessed and classified. RESULTS Two-way ANOVA revealed significant differences between treatments (P<0.0001), conditioners (P<0.0001) and a significant interaction between treatments and conditioners (P=0.001). One-way ANOVA revealed no significant differences in MSBS following any of the treatments for SB; following TM application for CSE without preconditioning; and significant differences in MSBS following bleaching with and without TM application for CSE. With preconditioning, applying PA before CSE post-bleaching and either PA or CC before CSE post-TM application, resulted in significant differences in MSBS (P<0.05). CONCLUSIONS The use of conditioners prior to bonding with the self-etching primer adhesive system on treated enamel may significantly improve bond strengths.