Effect of radiotherapy on the radiopacity and flexural strength of a composite resin.

The aim of this study was to evaluate the effect of radiotherapy on the radiopacity and flexural strength of composite resin. Forty Z250 composite resin specimens were polymerized using a halogen light-curing unit and divided into 5 groups, in accordance with the radiotherapy dose: G1- without irradiation, G2- 30 Gy, G3- 40 Gy, G4- 50 Gy and GS- 60 Gy Digital images were obtained using a GE 100 X-ray. Radiopacity values were obtained with the Digora digital imaging system and the flexural strength was evaluated with an EMIC universal testing machine. Data were submitted to ANOVA and Tukey 's test. G1 presented the highest radiopacity value, followed by G3, G5, G4 and G2. For flexural strength, G1 presented the lowest value, followed by G2, G5, G3 and G4. Differences were no significant (p>0.05). The commonly used dosage of radiotherapy treatment, did not cause alteration in the radiopacity and flexural strength of resin-based composites.

Influência dos agentes clareadores na microdureza de resina composta nanoparticulada

Objective: To assess the effect of bleaching agents on the microhardness of nanoparticle resin composite. Methods: Twenty-eight cylindrical test specimens (8× 1mm) of Filtek™ Supreme XT resin (3M/ESPE) were prepared and divided into 5 groups. The initial Vickers microhardness was measured (load of 50 grams force for 30 seconds) on the top surface of the test specimens. The groups were treated and divided as follows: G1 - artificial saliva (21 days - control); G2 - 7% hydrogen peroxide gel applied for 4h/day, for 14 days; G3 - 10% carbamide peroxide for 4h/day, for 14 days: G4 - 35% hydrogen peroxide gel applied in three sessions of 30 minutes each, with an interval of one week (21 days) between the sessions; G5 - 35% carbamide peroxide, three sessions of 30 minutes each, with an interval of one week (21 days) between the sessions. The top surfaces of the test specimens received treatment and were submitted to the Vickers microhardness test. Results: The results obtained were submitted to the Analysis of Variance at a fixed criterion, at a level of significance of p=0.05. No significant differences were observed among the treatments tested (p=0.42) when compared with G1. Significant differences (Tukey test) were found when the initial microhardness values were compared with the values after experimental treatments (p<0.01). Conclusion: The application of bleaching agents did not alter the microhardness of resin composites. Therefore, there is no need to change restorations after bleaching.

Experimental vaccination against Newcastle disease in Japanese quails (Coturnix coturnix japonica): Clinical and immunological parameters

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of creatine kinase (CK) and aspartate aminotransferase (AST) activities after laparoscopic or conventional ovariectomy in queens

Creatine kinase (CK) and aspartate aminotransferase (AST) are mainly muscle-specific enzymes, which can be associated with muscle tissue damage. The aim of this study was to assess the activities of CK and AST during the postoperative period, after conventional (G1) and videolaparoscopic ovariectomy (G2), in queens. A further group (G3) was subjected to anaesthesia only. Results demonstrate that there were significant differences between groups. The highest levels of CK were recorded in Gl, however at a confidence level of p < 0.05 there was no significant difference between groups during the first 6 hours after surgery. A significant (p < 0.05) increase of CK values was identified between 0h and 3h in both groups (Gl and G2). Regarding AST activity there was no significant variation between groups, but again there was a significant difference between values at 0h and 3h after surgery. In conclusion, ovariectomy performed by videolap-aroscopy seems to cause less muscle damage when compared to the conventional method. © 2009 by Verlag Hans Huber, Hogrefe AG, Bem.

Dietary restriction abrogates antibody production induced by a DNA vaccine encoding the mycobacterial 65 kDa heat shock protein

Background: Protein-calorie malnutrition (PCM) is the most common type of malnutrition. PCM leads to immunodeficiency and consequent increased susceptibility to infectious agents. In addition, responses to prophylactic vaccines depend on nutritional status. This study aims to evaluate the ability of undernourished mice to mount an immune response to a genetic vaccine (pVAXhsp65) against tuberculosis, containing the gene coding for the heat shock protein 65 from mycobacteria. Methods: Young adult female BALB/c mice were fed ad libitum or with 80% of the amount of food consumed by a normal diet group. We initially characterized a mice model of dietary restriction by determining body and spleen weights, hematological parameters and histopathological changes in lymphoid organs. The ability of splenic cells to produce IFN-gamma and IL-4 upon in vitro stimulation with LPS or S. aureus and the serum titer of specific IgG1 and IgG2a anti-hsp65 antibodies after intramuscular immunization with pVAXhsp65 was then tested. Results: Dietary restriction significantly decreased body and spleen weights and also the total lymphocyte count in blood. This restriction also determined a striking atrophy in lymphoid organs as spleen, thymus and lymphoid tissue associated with the small intestine. Specific antibodies were not detected in mice submitted to dietary restriction whereas the well nourished animals produced significant levels of both, IgG1 and IgG2a anti-hsp65. Conclusion: 20% restriction in food intake deeply compromised humoral immunity induced by a genetic vaccine, alerting, therefore, for the relevance of the nutritional condition in vaccination programs based on these kinds of constructs. © 2009 Ishikawa et al; licensee BioMed Central Ltd.

Changes on transmittance mode of different composite resins

The purpose of this study was to evaluate the transmittance of seven different composite resins. Ten specimens were prepared (10 mm diameter, 2 mm thickness) for each experimental group, as follows: G1- Charisma® A 2 (Heraeus-Kulzer); G2- Filtek™ Supreme A 2E (3M/ESPE); G3- Filtek™ Supreme A2B (3M/ESPE); G4-Filtek™ Supreme YT (3M/ESPE); G5- Esthet-X® A2 (Dentsply); G6- Esthet-X® YE (Dentsply); G7- Durafill® A 2 (Heraeus-Kulzer) and G8- Filtek™ Z-100 A2 (3M/ESPE). The transmittance mode was measured using a UV-visible spectrophotometer (Cary Instruments) at 400-760 nm. The specimens were evaluated at three different times: zero hour (initial), 24 hours and 10 days after immersion in artificial saliva. The differences in transmittance were determined by two-way analysis of variance (ANOVA) and Tukey's test. The various composite resins showed significant differences in the wavelength dependence of transmittance. The mean values of transmittance increased significantly, with wavelengths increasing from 400 to 760 nm. The performance of the experimental groups was similar in terms of immersion time, considering that at time zero and after 10 days, all the groups showed similar results, which were statistically higher than the values obtained after 24 hours of immersion. The Filtek™ Supreme YT composite resin presented the highest mean transmittance values along the wavelengths at the three measured times. Esthet-X® YE and Durafill® yielded similar mean transmittance values, which were higher than those of the other groups. This study shows that the transmittance values of composite resins are directly related with the type, size and amount of inorganic filler particles.

Influence of desensitizing agents on the microshear bond strength of adhesive systems to dentin.

The aim of this study was to evaluate the effect of desensitizing agents on the micro-shear bond strength of adhesive systems to dentin. Forty bovine teeth were divided into 8 groups (n=5): G1--Single Bond (SB); G2--GH.F + SB; G3-- Desensibilize + SB; G4--essensiv + SB; G5 --ingle Bond 2 (SB2); G6--H.E + SB2; G7--esensibilize + SB2; G8--Dessensiv + SB2. In all of the groups, the desensitizing agents were applied after phosphoric acid etching and before the dentin adhesive application. Z250 composite resin tubes were bonded on the treated surface. After 24 hours, the teeth were tested in a universal machine. Data were submitted to ANOVA and Tukey's test (5%). The results showed that the groups where Desensibilize and Dessensiv were applied exhibited smaller bond strength values.

Indirect cytotoxicity of a 35% hydrogen peroxide bleaching gel on cultured odontoblast-like cells

The aim of this study was to evaluate the trans-enamel and trans-dentinal effects of a 35% hydrogen peroxide (H2O2) bleaching gel on odontoblast-like cells. Enamel/dentin discs obtained from bovine incisors were mounted in artificial pulp chambers (APCs). Three groups were formed: G1- 35% H2O2; G2- 35% H2O2 + halogen light application; G3- control. The treatments were repeated 5 times and the APCs were incubated for 12 h. Then, the extract was collected and applied for 24 h on the cells. Cell metabolism, total protein dosage and cell morphology were evaluated. Cell metabolism decreased by 62.09% and 61.83% in G1 and G2, respectively. The depression of cell metabolism was statistically significant when G1 and G2 were compared to G3. Total protein dosage decreased by 93.13% and 91.80% in G1 and G2, respectively. The cells in G1 and G2 exhibited significant morphological alterations after contact with the extracts. Regardless of halogen light application, the extracts caused significantly more intense cytopathic effects compared to the control group. After 5 consecutive applications of a 35% H2O2 bleaching agent, either catalyzed or not by halogen light, products of gel degradation were capable to diffuse through enamel and dentin causing toxic effects to the cells.

Response to experimental vaccination against newcastle disease in domestic ducks (Anas platyrhynchos): Clinical and immunological parameters

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Educação em saúde: Efeito de um método de auto-instruçáo sobre os níveis de higiene oral em escolares

Objective: To identify the effect of a self-instructive method (comic strip), applied with distinct approaches and evaluated over two periods, on the oral health of schoolchildren. Method: The sample comprised 2nd year elementary schoolchildren chosen randomly and divided into four groups: a control group (G1) which received no material, a reading group (G2), which was given the comic strip and read it in the classroom, a discussion group (G3), who received the comic strip, which was read out loud in the classroom and discussed, and a complete group (G4), which received the comic strip and which, after reading it, was asked to rewrite the story. O'Leary's plaque index was used as an evaluation instrument, measured immediately prior to application of the program and again 30 days later. The plaque index measured after and 30 days was compared, in each group, using the Wilcoxon test. The plaque index of the diferents groups was compared using the Kruskal-Walis test, in two moments diferents. The significance level was 5%. Results: The results of the evaluation revealed a statistically significant reduction (p<0.05) of the plaque index presented between the two periods in the four groups studied here. However, this reduction was considerably greater in the discussion and complete groups. Conclusion: The use of the self-instruction method associated with work on its content, as occurred in the discussion and complete groups, led to a better understanding of the subject matter, resulting in a higher reduction of plaque indices.

Influence of bleaching treatment on flexural resistance of hybrid materials.

The aim of this study is to evaluate the flexural resistance of three types of restorative materials: compomer (Freedom), resin-modified glass-ionomer (Vitremer) and composite resin (Esthet-X), observing whether the application of bleaching agent can cause alterations of their flexural properties. Sixty samples were made using a 10 x 1 x 1 mm brass mold, and divided into three groups: G1- Freedom (SDI); G2- Vitremer (3M ESPE); G3- Esthet-X (Dentsply). On half of the samples of each group (10 samples) the bleaching treatment was applied and the other half used as control, was stored in distilled water at a temperature of 37 degrees C. Whiteness HP Maxx bleaching system was applied on the sample surface following the manufacturer's recommendations, simulating the bleaching treatment at the clinic. After this period, a flexural strength (three-point bending) test was conducted using (EMIC DL 1000) machine until the samples fractured. The data were submitted to ANOVA and Tukey tests. Of the restorative materials studied, G3-(87.24 +/- 31.40 MPa) presented the highest flexural strength, followed by G1-(61.67 +/- 21.32 MPa) and G2-(61.67 +/- 21.32 MPa). There was a statistical difference in flexural strength after the bleaching treatment. It was concluded that the use of a beaching agent can promote significant alteration of the flexural strength of these restorative materials.

Resposta imune e capacidade de neutralização de anticorpos produzidos em ovinos jovens imunizados com veneno de Crotalus durissus terrificus nativo e irradiado com Cobalto 60

The ELISA technique was used to evaluate and compare young ovine humoral immune response during crotalic antiserum production. Animals were clinically evaluated throughout this process, and the neutralizing capacity of antisera raised against natural (NV) and Cobalt-60 irradiated (IrV) venoms of Crotalus durissus terrificus (C.d.t.) was verified by means of in vitro challenges. Three groups of six animals each were used: G1 received NV; G2 was inoculated with IrV; and G3 was used as control. Animals received six immunizations during 84 days at 14-day intervals. ELISA of antibody profile showed significant difference (p<5%) between experimental groups (G1

Estudo comparativo entre o tratamento radioterápico com elétrons e betaterapia, após cirurgia de queloides

Introduction: The surgery of keloids as an individual therapy with high rates of recurrence needs adjuvant therapies as complement. Recent keloids are rich in fibroblasts, which are highly radiosensitive and what explains the good results of percutaneous radiotherapy after surgery. Objective: To compare the beta-therapy results with electron-beam technique in newly operated keloids. Material and Methods: a prospective, comparative and randomized study was outlined including patients in the immediate postoperative period of surgical excision of keloids. Divided in G1 and G2 groups respectively, they received treatment with Sr90 (beta-therapy)plates or with electrons from the linear accelerator. The monitoring lasted 10 years. The results were performed using the information from patients, photograph parameters, observation and measurement of injuries, according to the criteria: Unchanged, Regular, Good and Excellent. Results: There were 26 patients, 13 in each group. In G1, 54% presented regular and unchanged improvement criteria and 46% had good or excellent criteria. In G2, the results were respectively 23% and 77%. Conclusion: The irradiation with electron-beam is better than beta-teraphy for the treatment of keloids surgery, due to the distribution in the tissue. No radio-induced tumors were observed.

Cytotoxic effects of white-MTA and MTA-Bio cements on odontoblast-like cells (MDPC-23)

This study evaluated the cytotoxic effects of 2 mineral trioxide aggregate (MTA) cements - White-MTA-Angelus and a new formulation, MTA-Bio - on odontoblast-like cell (MDPC-23) cultures. Twenty-four disc-shaped (2 mm diameter x 2 mm thick) specimens were fabricated from each material and immersed individually in wells containing 1 mL of DMEM culture medium for either 24 h or 7 days to obtain extracts, giving rise to 4 groups of 12 specimens each: G1 - White-MTA/24 h; G2 - White-MTA/7 days; G3 - MTA-Bio/24 h; and G4 - MTA-Bio/7 days. Plain culture medium (DMEM) was used as a negative control (G5). Cells at 30,000 cells/cm 2 concentration were seeded in the wells of 24-well plates and incubated in a humidified incubator with 5% CO 2 and 95% air at 37°C for 72 h. After this period, the culture medium of each well was replaced by 1 mL of extract (or plain DMEM in the control group) and the cells were incubated for additional 2 h. Cell metabolism was evaluated by the MTT assay and the data were analyzed statistically by ANOVA and Tukey's test (α=0.05). Cell morphology and the surface of representative MTA specimens of each group were examined by scanning electron microscopy. There was no statistically significant difference (p>0.05) between G1 and G2 or between G3 and G4. No significant difference (p>0.05) was found between the experimental and control groups either. Similar cell organization and morphology were observed in all groups, regardless of the storage periods. However, the number of cells observed in the experimental groups decreased compared to the control group. MTA-Bio presented irregular surface with more porosities than White-MTA. In conclusion, White-MTA and MTA-Bio presented low cytotoxic effects on odontoblast-like cell (MDPC-23) cultures.

Experimental infection of commercial layers using a Salmonella enterica serovar Gallinarum strain: Leukogram and serum acute-phase protein concentrations

The aim of the present study was to evaluate white blood cell counts and serum protein profiles of commercial layers experimentally infected with Salmonella Gallinarum (SG) in order to better understand the pathophysiology of the disease caused by this bacterium. 180 five-day-old commercial layers were divided into 3 groups (G); G1 and G2 received 0.2 mL of inoculate containing 3.3x10 8 CFU or 3.3×10 5 CFU SG resistant to nalidix acid (Nal r)/mL, respectively, directly into their crops. G3 group did not receive the inoculum. Birds were sacrificed 24 hours before (T1) and 24 hours after the infection (T2), and three (T3), five (T4), seven (T5), and ten (T6) days after the administration of the inoculum. White blood cell counts were carried out in a Neubauer hemocytometer and in blood smears. Serum protein concentrations, including acute-phase proteins, were determined using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Data were submitted to analysis of variance, and means were compared by Tukey's test (P <0.05). G1 and G2 groups presented higher leukocyte counts on T4 and T5, respectively, due to the increase of circulating lymphocytes and heterophils, with a significant difference relative to G3. In electrophoresis, an increase in the serum levels of ceruloplasmin, haptoglobin, and hemopexin and a decrease in transferrin, which are acute-phase proteins, was verified. IgA serum levels did not change; however, IgG concentration increased during the infection. In conclusion, the results provide information for the better understanding of the pathophysiology of fowl typhoid.