Effect of thickness of CAD/CAM materials on light transmission and resin cement polymerization using a blue light-emitting diode light-curing unit.

OBJECTIVE: Evaluate the effect of thickness of high-translucency (HT) CAD/CAM materials on irradiance and beam profile from a blue light-emitting diode light-curing unit (LCU) and on the degree of conversion (DC) and maximum polymerization rate (Rpmax ) of a light-cured resin cement (LCC). MATERIAL AND METHODS: The direct output from the LCU, the light transmission and irradiance ratio (IR) through one conventional composite and nine HT CAD/CAM materials (0.5, 1.0, 1.5, or 2.0-mm thick; n = 5) were measured with a integrating sphere coupled to a spectrometer. The light beam was assessed with a beam profiler camera. The DC at 600 s and the Rpmax of one LCC was determined using a Fourier transform infrared spectrometer (n = 5). Data were analyzed by ANOVA followed by Tukey's tests, and Dunnett's test was also used for irradiance data (α = 0.05). RESULTS: A significant decrease in irradiance through all materials occurred as thickness increased. Thin CAD/CAM materials improved light homogeneity, which decreased with the increase in thickness. The DC of the LCC directly exposed to light was the same as when exposed to 45%, 25%, 15%, or 5% IRs. Rpmax decreased with the decrease in IR. CONCLUSIONS: Although the HT CAD/CAM materials reduced the irradiance from the LCU, minor effects were observed in the LCC's DC. CLINICAL SIGNIFICANCE: Despite the light attenuation of blue light through different CAD/CAM materials that were up to 2-mm thick, the degree of conversion of one brand of light-cured resin cement was clinically acceptable when the LCU was used for 30 s.

Candida species biotypes and polyclonality of potentially virulent Candida albicans isolated from oral cavity of patients with orofacial clefts.

OBJECTIVES: This study evaluated the incidence of Candida species, and the genetic diversity and virulence of C. albicans of the oral cavity from patients with cleft lip and palate (CLP). MATERIALS AND METHODS: Oral samples were investigated by microbiological and species-specific PCR methods. The genetic diversity of C. albicans was established using isoenzyme markers, Nei's statistics, and clustering analysis. Hydrolytic enzymes (SAPs and PLs) were analyzed in vitro. RESULTS: Oral colonization by Candida species was observed in 29 patients with CLP (65.9%), and C. albicans was highly prevalent. SAP and PL activities were observed in 100% and 51.9% of isolates, respectively. High genetic diversity and patterns of monoclonal and polyclonal oral colonization by C. albicans were observed among patients with CLP. Two major polymorphic taxa (A and B) and other minor polymorphic taxa (C to J) were identified. Only one of the 16 clusters (taxon A) harbored strains from patients with and without CLP, whereas other clusters harbored strains exclusively from CLP patients. CONCLUSIONS: The anatomical conditions of the oral cavity of patients with CLP contribute to the high incidence of Candida species (C. albicans, C. krusei, C. tropicalis, and/or Candida spp.). Data suggest high genetic diversity of potentially virulent C. albicans strains in the oral cavity of CLP patients. CLINICAL RELEVANCE: Microbiological niches in orofacial clefts can contribute to the emergence of a relative clinical genotypic identity of C. albicans. However, orofacial rehabilitation centers can contribute to the direct and indirect sources of transmission and propagation of Candida species.

Antimicrobial potential, phytochemical profile, cytotoxic and genotoxic screening of Sedum praealtum A. DC. (balsam).

BACKGROUND: Sedum praealtum has been used for a long time in traditional medicine as an analgesic and anti-inflammatory agent. Its beneficial effects have been known since ancient times, when Latinos used it to treat sore and swollen eyes. This research evaluated the antimicrobial potential, the cytotoxic and genotoxic effects, and some chromatographic profiles of the hydroethanolic extract of leaves, stems and roots of S. praealtum. METHODS: The antimicrobial activities were carried out by broth microdilution and agar diffusion. In vitro cytotoxicity was evaluated by cell cultures of Aedes albopictus and the selectivity index (SI) was estimated: SI=CI50/MIC. Genotoxic and systemic toxic effects of S. praealtum leaves were analyzed by micronucleus assay in mice bone marrow. Chromatographic profiles and mass spectra were investigated by GC-MS. RESULTS: Gram-positive (B. subtilis, B. cereus, M. luteus, E. faecalis and S. aureus) and gram-negative (E. coli, E. aerogenes, S. marcescens, P. aeruginosa, P. mirabilis and S. typhimurium) bacteria exhibited MICs ranging from 12.5-50 and 0-50 mg/ml, respectively. Sedum praealtum showed no efficacy against M. tuberculosis and M. bovis. Cytotoxicity (CI50) of S. praealtum was 4.22 and 5.96 mg/ml for leaves and stems, respectively, while its roots showed no cytotoxicity. Micronucleated polychromatic erythrocytes (MNPCEs) analyzes showed no differences between treatment doses (0.5-2 g/kg) and negative control (NaCl), but the PCE/NCE ratio (polychromatic erythrocyte/normochromatic erythrocyte) showed significant differences. Phytochemical screening identified thirteen compounds in the leaves, stems and roots of S. praealtum potentially associated with their biological activities. CONCLUSIONS: This research comprises a first scientific study on genotoxicity, cytotoxicity and antimicrobial effects of S. praealtum (Balsam), and it provides an initial theoretical foundation for its comprehensive use. Results showed antibacterial action of S. praealtum against gram-positive bacteria and some gram-negative species (depending on the plant anatomical part), but ineffective antimycobacterial action. However, S. praealtum leaves and stems display potential cytotoxicity, contributing to the SI < 1 values. In addition, S. praealtum leaves exhibit no clastogenic and/or aneugenic effects, but it has systemic toxicity dose-independent.

Month-wise variation and prediction of bulk tank somatic cell count in Brazilian dairy herds and its impact on payment based on milk quality.

BACKGROUND: Payment programs based on milk quality (PPBMQ) are used in several countries around the world as an incentive to improve milk quality. One of the principal milk parameters used in such programs is the bulk tank somatic cell count (BTSCC). In this study, using data from an average of 37,000 farms per month in Brazil where milk was analyzed, BTSCC data were divided into different payment classes based on milk quality. Then, descriptive and graphical analyses were performed. The probability of a change to a worse payment class was calculated, future BTSCC values were predicted using time series models, and financial losses due to the failure to reach the maximum bonus for the payment based on milk quality were simulated. RESULTS: In Brazil, the mean BTSCC has remained high in recent years, without a tendency to improve. The probability of changing to a worse payment class was strongly affected by both the BTSCC average and BTSCC standard deviation for classes 1 and 2 (1000-200,000 and 201,000-400,000 cells/mL, respectively) and only by the BTSCC average for classes 3 and 4 (401,000-500,000 and 501,000-800,000 cells/mL, respectively). The time series models indicated that at some point in the year, farms would not remain in their current class and would accrue financial losses due to payments based on milk quality. CONCLUSION: The BTSCC for Brazilian dairy farms has not recently improved. The probability of a class change to a worse class is a metric that can aid in decision-making and stimulate farmers to improve milk quality. A time series model can be used to predict the future value of the BTSCC, making it possible to estimate financial losses and to show, moreover, that financial losses occur in all classes of the PPBMQ because the farmers do not remain in the best payment class in all months.

Oral administration of banana lectin modulates cytokine profile and abundance of T-cell populations in mice.

Banana lectin (BanLec) is a dimeric protein occurring in fruit pulp that modulates immune cell functioning in vitro. In order to assess the immune response in vivo, BanLec from ripe banana (Musa acuminata) fruit was purified and orally given to mice for seven days. The analysis of cytokines in the mice peripheral blood revealed increased IL-10, IL-17 and TNFα, and a reduction of IFNγ and IL-6. In the thymus, an increase of CD4+ and a decrease of CD8+ T-cells were observed after oral administration of BanLec. The modulation of pro- and anti-inflammatory cytokines and T-cells in the peripheral blood and thymus of mice demonstrated the immunomodulatory properties of natural BanLec in vivo. This research brings new data on a protein from a fresh fruit consumed worldwide that may act as an immunomodulator, potentially affecting the host response to infections, immune diseases and cancer.

Characterisation and potential application of pineapple pomace in an extruded product for fibre enhancement.

This study characterised pineapple pomace (PP) and evaluated its application in extrusion to enhance fibre content of the final product. The pomace had low fat (0.61%) and high dietary fibre (45.22%), showing its potential for fibre enrichment of nutritionally poor products, as some extruded snacks. Results also showed low microbiological counts, water activity, and pH indicating good microbiological quality and low risk of physicochemical deterioration. During extrusion, pomace (0%, 10.5% and 21%), moisture (14%, 15% and 16%) and temperature (140 and 160°C) were evaluated. The PP addition decreased expansion and luminosity; while increasing redness of the extrudates compared to the control (0% pomace/14% moisture/140°C). When hardness, yellowness, water absorption, and bulk density were compared to the control, there was no effect (p>0.05) of 10.5% PP addition on the extrudates, indicating that, at this level, PP could be added without affecting the properties of the final extruded product.

Evaluation of the effectiveness of a voice training program for teachers.

OBJECTIVES: To investigate the effects of a voice education program to teachers on vocal function exercise and voice hygiene and compare a pre- and post-vocal exercise for the teacher's voice quality. METHODS: A random sample of 102 subjects was divided into two groups: experimental group (29 women and seven men) with vocal hygiene and training exercises and control group (52 women and 14 men) with vocal hygiene. Two sessions were held about voice hygiene for the control group and five sessions for the experimental group, one being with reference to the vocal hygiene habit and four vocal exercise sessions. Acoustic analysis of the vowel [i] was made pre- and post-vocal exercise and for the situations of initial and final evaluation of the educational program. Student t test (paired) and Proc MIXED (repeated measures) were used for analyses with level of significance (α = 0.05). RESULTS: The training exercises, posture and relaxation cervical, decreased the mean of fundamental frequency (f(0)) for men (P = 0.04), and for the phonation, intensity, and frequency exercises, there was a significant increase for f(0) in woman (P = 0.02) and glottal to noise excitation ratio (P = 0.04). There was no statistically significant difference intergroup evaluations after 3 months. The control group presented increased mean voice intensity in the final evaluation (P = 0.01). CONCLUSIONS: Voice training exercises showed a positive and immediate impact on the teacher's quality of voice, but it was not sustained longitudinally, suggesting that actions for this purpose should be continued at schools.

Increased antioxidant content in juice enriched with dried extract of pomegranate (Punica granatum) peel.

Antioxidants are compounds responsible for free radical scavenging in the body. They protect the organism from oxidative modification of cells and tissues. These modifications have been associated with degenerative diseases, atherosclerosis and carcinogenesis. Punica granatum displays high antioxidant potential due to the presence of phenolic compounds, which are capable of disease prevention. The present study showed the highest antioxidant activity in pomegranate peel than in seeds and pulp. Based on these results, pomegranate peel was used to produce dried extract that was added to commercial tomato juice and orange juice with strawberries. Analysis to determine the content of phenolic compounds and antioxidant activity was performed on pomegranate pulp, seeds and peel and in juices enriched with dried extract of pomegranate peel. The dried extract was responsible for a significant increase in antioxidant activity of the juices, proportional to the concentrations added. However, although both flavors of enriched juices displayed high antioxidant levels, the samples with higher dried extract concentrations received the lowest scores from sensory analysis participants due to the characteristic astringent flavor of pomegranate peels. Therefore, to obtain greater acceptance in the consumer market, we concluded that the maximum addition of dried pomegranate peel extract is 0.5% in tomato juice and orange juice with strawberries.

Cupuassu (Theobroma grandiflorum) peel as potential source of dietary fiber and phytochemicals in whole-bread preparations.

Cupuassu (Theobroma grandiflorum) is a fruit tree native to the Brazilian Amazon. Cupuassu beans are extensively used in the Brazilian food industry. Fat from cupuassu beans, which are a rich source of triacylglycerols and fatty acids, is used extensively in the production of candies and confectionery in the northern and northeastern regions of Brazil. The potential use of the agro-industrial by-products of cupuassu has only slightly been addressed by the scientific community. Often, such by-products are sources of bioactive compounds with functional properties. Thus, the aims of this study were to characterize the use of cupuassu peel flour (CPF) and to examine the potential of CPF as a partial replacement in the preparation of breads through various means: chemical analyses, determination of protein digestibility, tannins, phytic acid and phenolic contents, pH, color, volume, and acceptance tests. The results show that CPF is a potential source of dietary fiber (79.81%), mainly insoluble fiber (78.29%), and breads made with added CPF present high dietary fiber content (5.40 and 6.15 g/100 g for inclusions with 6 and 9% CPF, respectively) and phytochemical values. The use of this by-product did not produce substantial changes in the physical, chemical or rheological characteristics of breads. Therefore, breads enhanced with CPF may be a convenient functional food, offering a good source of dietary fiber and phytochemicals. Breads prepared with 6% added CPF presented an acceptable overall quality to consumers.

Surface finishing of resin-modified glass ionomer.

This study utilized spectrophotometry to evaluate in vitro superficial dye deposition on resin-modified glass ionomer, following different surface finishing and polishing treatments. Materials that were photocured adjacent to the mylar strip produced the surfaces with the lowest mean after superficial staining. A restorative technique without excesses resulted in a smoother surface and prolonged the life of the restoration. The resin-modified glass ionomers tested offer adequate clinical performance.

The effect of six polishing systems on the surface roughness of two packable resin-based composites.

PURPOSE: To evaluate the surface roughness of two packable composites after finishing and polishing with six different systems. MATERIALS AND METHODS: Solitaire and Alert composite samples were prepared and polished with Poli I and Poli II aluminum oxide pastes, Ultralap diamond paste, Enhance finishing points, Politip rubber polishers, fine and extra fine diamond burs, and 30-blade tungsten carbide burs according to the manufacturers' instructions. The polished surfaces were then evaluated with a profilometer and a scanning electron microscope. RESULTS: Solitaire composite resin presented the smoothest surfaces when polished with Poli I and II aluminum oxide pastes, Ultralap diamond paste, Politip finishing points and 30-blade tungsten carbide burs. The smoothest surfaces for Alert composite were evident with the 30-blade tungsten carbide burs.