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Dos Santos C.C.,Ibirapuera University | Santos E.L.,Santa Cecilia University | Goncalves F.,Ibirapuera University
Water Science and Technology: Water Supply | Year: 2017

Fluorosilicic acid is one of the main products used in water fluoridation. As a by-product of the phosphate fertilizer industry, it may contain contaminants that are harmful to human health. The aims of this study were to assess the quality control analysis of fluorosilicic acid; to detect the presence of contaminants, such as arsenic, lead, cadmium, aluminum, barium, strontium, cobalt, iron, and sulfur in fluorosilicic acid samples by using inductively coupled plasma-optical emission spectrometry; and to collect data for water analysis performed at a water treatment plant. The results show the presence of all contaminants mentioned previously, except for lead, in fluorosilicic acid samples from all sources. No quality control was carried out or required for this product at any time. Although the water analyses indicate the water is potable, there are no minimum safe limits for human consumption regarding carcinogenic elements such as cadmium and arsenic and both were detected and released in the water. Therefore, the purity of fluorosilicic acid used for water fluoridation should be required and monitored by public administrations to avoid long-term public health problems. © 2017 IWA Publishing.


Calheiros F.C.,Ibirapuera University | Daronch M.,NY University | Rueggeberg F.A.,Georgia Regents University | Braga R.R.,University of Sao Paulo
Dental Materials | Year: 2014

Objective To test the following hypotheses: (1) degree of conversion (DC) and polymerization stress (PS) increase with composite temperature (2) reduced light-exposure applied to pre-heated composites produces similar conversion as room temperature with decreased PS. Methods Composite specimens (diameter: 5 mm, height: 2 mm) were tested isothermally at 22 °C (control), 40 °C, and 60 °C using light-exposures of 5 or 20 s (control). DC was accessed 5 min after light initiation by FTIR at the specimen bottom surface. Maximum and final PS were determined, also isothermally, for 5 min on a universal testing machine. Non-isothermal stress was also measured with composite maintained at 22 °C or 60 °C, and irradiated for 20 s at 30 °C. Data were analyzed using two-way ANOVA/Tukey and Student's t-test (α = 5%). Results Both DC and isothermal maximum stress increased with temperature (p < 0.001) and exposure duration (p < 0.001). Isothermal maximum/final stress (MPa) were 3.4 ± 2.0b/3.4 ± 2.0A (22 °C), 3.7 ± 1.5b/3.6 ± 1.4A (40 °C) and 5.1 ± 2.0a/4.0 ± 1.6A (60 °C). Conversion values (%) were 39.2 ± 7.1c (22 °C), 50.0 ± 5.4b (40 °C) and 58.5 ± 5.7a (60 °C). The reduction of light exposure duration (from 20 s to 5 s) with pre-heated composite yielded the same or significantly higher conversion (%) than control (22 °C, 20 s/control: 45.4 ± 1.8b, 40 °C, 5 s s: 45.1 ± 0.5b, 60 °C, 5 s s: 53.7 ± 2.7a, p < 0.01). Non-Isothermal conditions showed significantly higher stress for 60 °C than 22 °C (in MPa, maximum: 4.7 ± 0.5 and 3.7 ± 0.4, final: 4.6 ± 0.6 and 3.6 ± 0.4, respectively). Clinical significance: Increasing composite temperature allows for reduced exposure duration and lower polymerization stress (both maximum and final) while maintaining or increasing degree of conversion. © 2014 Academy of Dental Materials.


Beltrame T.,University of Waterloo | Beltrame T.,Brazilian National Council for Scientific and Technological Development | Beltrame T.,Ibirapuera University | Hughson R.L.,University of Waterloo
Frontiers in Physiology | Year: 2017

The temporal dynamics of the oxygen uptake (V.O2) during moderate exercise has classically been related to physical fitness and a slower V.O2 dynamics was associated with deterioration of physical health. However, methods that better characterize the aerobic system temporal dynamics remain challenging. The purpose of this study was to develop a new method (named mean normalized gain, MNG) to systematically characterize the V.O2 temporal dynamics. Eight healthy, young adults (28 ± 6 years old, 175 ± 7 cm and 79 ± 13 kg) performed multiple pseudorandom binary sequence cycling protocols on different days and time of the day. The MNG was calculated as the normalized amplitude of the V.O2 signal in frequency-domain. The MNG was validated considering the time constant t obtained from time-domain analysis as reference. The intra-subject consistency of the MNG was checked by testing the same participant on different days and times of the day. The MNG and t were strongly negatively correlated (r = -0.86 and p = 0.005). The MNG measured on different days and periods of the day was similar between conditions. Calculations for the MNG have inherent filtering characteristics enhancing reliability for the evaluation of the aerobic system temporal dynamics. In conclusion, the present study successfully validated the use of the MNG for aerobic system analysis and as a potential complementary tool to assess changes in physical fitness. © 2017 Beltrame and Hughson.


da Silva Rocha-Lopes J.,University of Sao Paulo | Machado R.B.,Ibirapuera University | Suchecki D.,University of Sao Paulo
Molecular Neurobiology | Year: 2017

Adolescence is marked by major physiological changes, including those in the sleep-wake cycle, such as phase delay, which may result in reduced sleep hours. Sleep restriction and/or deprivation in adult rats activate stress response and seem to be a risk factor for triggering emotional disorders. In the present study, we sought to evaluate the behavioral and neurobiological consequences of prolonged REM sleep restriction in juvenile male rats. Immediately after weaning, on postnatal day 21, three males from each litter were submitted to REM sleep deprivation and the other three animals were maintained in their home-cages. REM sleep restriction (REMSR) was accomplished by placing the animals in the modified multiple platform method for 18 h and 6 h in the home-cage, where they could sleep freely; the sleep restriction lasted 21 consecutive days, during which all animals were measured and weighed every 3 days. After the end of this period, all animals were allowed to sleep freely for 2 days, and then the behavioral tests were performed for evaluation of depressive and anxiety-like profiles (sucrose negative contrast test and elevated plus maze, EPM). Blood sampling was performed 5 min before and 30 and 60 min after the EPM for determination of corticosterone plasma levels. The adrenals were weighed and brains collected and dissected for monoamine levels and receptor protein expression. REMSR impaired the physical development of adolescents, persisting for a further week. Animals submitted to REMSR exhibited higher basal corticosterone levels and a greater anxiety index in the EPM, characteristic of an anxious profile. These animals also exhibited higher noradrenaline levels in the amygdala and ventral hippocampus, without any change in the expression of β1-adrenergic receptors, as well as higher serotonin and reduced turnover in the dorsal hippocampus, with diminished expression of 5-HT1A. Finally, greater concentration of BDNF was observed in the dorsal hippocampus in chronically sleep-restricted animals. Chronic REMSR during puberty impaired physical development and induced anxiety-like behavior, attributed to increased noradrenaline and serotonin levels in the amygdala and hippocampus. © 2017 Springer Science+Business Media New York


PubMed | University of Santo Amaro, University of Sao Paulo and Ibirapuera University
Type: Journal Article | Journal: Clinical oral investigations | Year: 2016

This study aims to correlate patient-reported reactions with in vitro analyses of the pH, abrasive quality, and cytotoxicity of four toothpastes.One hundred twenty-one patients received non-identified samples of toothpaste to be used for 6 days and answered a questionnaire about their sensations. In vitro analysis: the pH of toothpastes was measured with a pH meter. The abrasivity of toothpastes was evaluated against composite resin specimens (n=10). A toothbrushing machine was used to simulate wear, which was indirectly measured by mass loss using a scale. Cell culture media conditioned with toothpaste were used to assess the cytotoxicity. Confluent cells were kept in contact with the conditioned media or control for 24 h. The cell viability was measured using the 3-(bromide, 4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium (MTT)-reduction assay. The obtained data on the pH, weight loss, and cell viability were compared by ANOVA/Tukeys tests (p<0.05).With the exception of the bleaching effect paste, the Oral B paste produced the highest frequencies of irritation reports, tooth sensitivity, taste discomfort, and texture discomfort in the clinical study; patients also reported rougher teeth, soft tissue peeling, dry mouth, thrush, tingling, and taste changes in response to this paste. The in vitro analysis demonstrated that Oral B had the lowest pH, the highest abrasivity, and produced the lowest cell viability (p<0.01).Results suggest that low pH toothpastes that are highly abrasive and cytotoxic may cause undesirable reactions in patients.Toothpastes properties should be well known for indication to patient therefore minimizing discomfort reports.


PubMed | University of Santo Amaro, University of Sao Paulo and Ibirapuera University
Type: Journal Article | Journal: Brazilian oral research | Year: 2016

Nowadays, the main reasons for replacement of resin-based composite restorations are fracture or problems with the integrity of their interface, such as marginal staining, microleakage, or secondary caries. The aim of the present study was to evaluate the influence of the organic matrix on polymerization stress (PS), degree of conversion (DC), elastic modulus (E), flexural strength (FS), Knoop hardness (KHN), sorption (SP), and solubility (SL). In order to obtain a material which combines better mechanical properties with lower PS, seven experimental composites were prepared using BisGMA to TEGDMA molar ratios of 2:8, 3:7, 4:6, 5:5, 6:4, 7:3 and 8:2 and 40% of silica. PS was obtained in a universal testing machine, using acrylic as bonding substrate. DC was determined using Fourier Transform Raman spectroscopy. E and FS were obtained by the three-point bending test. KHN was measured by a microindentation test using a load of 25 g for 30 s. SP and SL were assessed according to ISO 4049. The data were submitted to one-way ANOVA. The increase in BisGMA concentration resulted in the decrease of PS, DC, E, FS and KHN. However, it did not change the SP and SL values. FS, E and KHN showed a strong and direct relationship with the DC of the materials. The composite material with a BisGMA to TEGDMA molar ratio of 1:1 was the one with better mechanical properties and lower PS.


PubMed | University of Sao Paulo and Ibirapuera University
Type: Journal Article | Journal: Odontology | Year: 2016

The aim of this study was to evaluate the influence of the physical assessment of different light-curing units from 55 dental offices on the irradiance and composite microhardness top/bottom ratio, and the influence of the radiometers for LED or QTH light sources on irradiance measurement. The irradiance of each light-curing unit was evaluated with two radiometers, either for LED or QTH light. A questionnaire regarding the type of source (LED or QTH), time of use, date of last maintenance and light-curing performance assessment applied. The physical assessments were evaluated regarding damage or debris on the light tip. For each light-curing unit, three composite specimens were made (diameter=7mm; thickness=2mm) with polymerizing time of 20s, in order to perform the microhardness (Knoop) test. Data were analyzed by Kruskal-Wallis and Dunn test (=0.01). There was wide variation in irradiance (0-1000 mW/cm(2)). Approximately 50% of the light-curing units presented radiation lower than 300mW/cm(2); 10% of light-curing units, especially those with LED source, presented values higher than 800 mW/cm(2), and 43% of light-curing units worked with adequate irradiance between 301 and 800 mW/cm(2). In almost 60% of cases, no maintenance of light-curing units was performed in a period of 3 to 10 years. The age of the light-curing units and the use of inadequate tips interfered negatively in irradiance. The data emphasize the importance of periodic maintenance of light-polymerizing, light-curing units.


PubMed | Federal University of São Paulo and Ibirapuera University
Type: | Journal: Hormones and behavior | Year: 2016

REM sleep rebound is a common behavioural response to some stressors and represents an adaptive coping strategy. Animals submitted to multiple, intermittent, footshock stress (FS) sessions during 96h of REM sleep deprivation (REMSD) display increased REM sleep rebound (when compared to the only REMSD ones, without FS), which is correlated to high plasma prolactin levels. To investigate whether brain prolactin plays a role in stress-induced REM sleep rebound two experiments were carried out. In experiment 1, rats were either not sleep-deprived (NSD) or submitted to 96h of REMSD associated or not to FS and brains were evaluated for PRL immunoreactivity (PRL-ir) and determination of PRL concentrations in the lateral hypothalamus and dorsal raphe nucleus. In experiment 2, rats were implanted with cannulas in the dorsal raphe nucleus for prolactin infusion and were sleep-recorded. REMSD associated with FS increased PRL-ir and content in the lateral hypothalamus and all manipulations increased prolactin content in the dorsal raphe nucleus compared to the NSD group. Prolactin infusion in the dorsal raphe nucleus increased the time and length of REM sleep episodes 3h after the infusion until the end of the light phase of the day cycle. Based on these results we concluded that brain prolactin is a major mediator of stress-induced REMS. The effect of PRL infusion in the dorsal raphe nucleus is discussed in light of the existence of a bidirectional relationship between this hormone and serotonin as regulators of stress-induced REM sleep rebound.


PubMed | Ibirapuera University
Type: Journal Article | Journal: Current opinion in endocrinology, diabetes, and obesity | Year: 2016

This review summarizes recent evidence on the impact of osteoporosis on periodontonlogy and implant dentistry, prevalence of diseases, pathophysiology and treatment outcomes.Patients with osteoporosis should be advised about the importance of returning for periodical periodontal maintenance as inadequate oral care may lead to a faster development of periodontitis. There is no definitive information on the development of bisphosphonate-related osteonecrosis of the jaw associated with dental implant therapy. Patients presenting severe periodontitis, undergoing intravenous bisphosphonate therapy (for long-term periods) and submitted to more invasive periodontal/peri-implant surgical procedures (that can promote superior dentoalveolar surgical trauma) might be advised about the possibility of developing bisphosphonate-related osteonecrosis of the jaw following dental therapy. Thus, individualized risk evaluation must be undertaken by both the medical and dental teams prior to any dental treatment.The most recent literature on the impact of osteoporosis on the periodontal and peri-implant tissues was reviewed to emphasize the importance of oral hygiene measures, and the combined medical/dental assessment of importance when osteoporotic patients are in need of dentoalveolar surgical procedures (e.g. tooth extraction and dental implant placement).


Chambrone L.,Ibirapuera University
Current Opinion in Endocrinology, Diabetes and Obesity | Year: 2016

PURPOSE OF REVIEW: This review summarizes recent evidence on the impact of osteoporosis on periodontonlogy and implant dentistry, prevalence of diseases, pathophysiology and treatment outcomes. RECENT FINDINGS: Patients with osteoporosis should be advised about the importance of returning for periodical periodontal maintenance as inadequate oral care may lead to a faster development of periodontitis. There is no definitive information on the development of bisphosphonate-related osteonecrosis of the jaw associated with dental implant therapy. Patients presenting severe periodontitis, undergoing intravenous bisphosphonate therapy (for long-term periods) and submitted to more invasive periodontal/peri-implant surgical procedures (that can promote superior dentoalveolar surgical trauma) might be advised about the possibility of developing bisphosphonate-related osteonecrosis of the jaw following dental therapy. Thus, individualized risk evaluation must be undertaken by both the medical and dental teams prior to any dental treatment. SUMMARY: The most recent literature on the impact of osteoporosis on the periodontal and peri-implant tissues was reviewed to emphasize the importance of oral hygiene measures, and the combined medical/dental assessment of importance when osteoporotic patients are in need of dentoalveolar surgical procedures (e.g. tooth extraction and dental implant placement). Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.

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