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Search Results: 1 - 10 of 2903 matches for " Robson Frederico;Delbem "
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Anticariogenic potencial of acidulate solutions with low fluoride concentration
Delbem, Alberto Carlos Botazzo;Tiano, Gilberto Carlos;Alves, Karina Mirela Ribeiro Pinto;Cunha, Robson Frederico;
Journal of Applied Oral Science , 2006, DOI: 10.1590/S1678-77572006000400004
Abstract: objetives: the aim of this study was to verify the anticariogenic effect of acidulate solutions with low naf concentration, using ph-cycling model and bovine enamel. material and methods: enamel blocks were submitted to the surface microhardness (smh) test and randomly divided in 12 experimental and one placebo groups. the blocks were submitted to ph cycling for 7 days, with daily applications once/day of 0.05% naf and 0.1% naf and twice/day of 0.02% naf solutions. four different ph: 4.0, 5.0, 6.0 and 7.0 were used. next, smh test was again used to determine the surface microhardness percentage change (%smh). data obtained for %smh were homogeneous and passed through variance analyses and tukey's test (5%) as far as fluoride concentrations and ph. results:the results showed that ph influenced %smh in 0.02% naf and 0.05% naf solutions with ph 4.0, which had less mineral loss compared to ph 7.0 (p<0.05). the 0.02% naf - ph 4.0, and 0.05% naf - ph 7.0 groups showed similar results (p>0.05). a dose-response relationship was observed among the tested solutions, with better anticariogenic effect for the 0.1% naf solution. conclusion: the results suggest that the addition of citric acid to acidulate mouth rinses reduce mineral loss.
Effect of fluoridated varnish and silver diamine fluoride solution on enamel demineralization: pH-cycling study
Delbem, Alberto Carlos Botazzo;Bergamaschi, Maurício;Sassaki, Kikue Takebayashi;Cunha, Robson Frederico;
Journal of Applied Oral Science , 2006, DOI: 10.1590/S1678-77572006000200005
Abstract: objective: in the present investigation, the anticariogenic effect of fluoride released by two products commonly applied in infants was evaluated. methods: bovine sound enamel blocks were randomly allocated to each one of the treatment groups: control (c), varnish (v) and diamine silver fluoride solution (d). the blocks were submitted to ph cycles in an oven at 37oc. next, surface and cross-sectional microhardness were assessed to calculate the percentage loss of surface microhardness (%sml) and the mineral loss (dz). the fluoride present in enamel was also determined. results: f/px10-3 (anova, p<0.05) in the 1st layer of enamel before ph-cycling were (c, v and d): 1.61a; 21.59b and 3.98c. the %smh (kruskal-wallis, p<0.05) were: -64.0a, -45.2b and -53.1c. %dz values (anova, p<0.05) were: -18.7a, -7.7b and -17.3a. conclusion: the data suggested that the fluoride released by varnish showed greater interaction with sound enamel and provided less mineral loss when compared with silver diamine solution.
Regional odontodysplasia: case report
Magalh?es, Ana Carolina;Pessan, Juliano Pelim;Cunha, Robson Frederico;Delbem, Alberto Carlos Botazzo;
Journal of Applied Oral Science , 2007, DOI: 10.1590/S1678-77572007000600002
Abstract: regional odontodysplasia (ro) is a rare developmental anomaly involving both mesodermal and ectodermal dental components in a group of contiguous teeth. it affects the primary and permanent dentitions in the maxilla and mandible or both jaws. generally it is localized in only one arch. the etiology of this dental anomaly is uncertain. clinically, affected teeth have an abnormal morphology, are soft on probing and typically discolored, yellow or yellowish-brown. radiographically, the affected teeth show a "ghostlike" appearance. this paper reports the case of a 5-year-old girl presenting this rare anomaly on the left side of the maxillary arch, which crossed the midline. the primary maxillary left teeth (except for the canine) and the primary maxillary right central incisor were missing due to previous extractions. the permanent teeth had a "ghostlike" appearance radiographically. the treatment performed was rehabilitation with temporary partial acrylic denture and periodic controls. in the future, the extraction of affected permanent teeth and rehabilitation with dental implants will be evaluated. the presentation of this case adds valuable information to pediatric dentists to review special clinical and radiographic features of ro, which will facilitate the diagnosis and treatment of patients with this condition.
The association between prune belly syndrome and dental anomalies: a case report
Basso Maria Daniela,Favretto Carla Oliveira,Cunha Robson Frederico
BMC Oral Health , 2012, DOI: 10.1186/1472-6831-12-56
Abstract: Background Prune belly syndrome is a rare condition produced by an early mesodermal defect that causes abdominal abnormalities. However, the literature indicates that disturbances related to ectodermal development may also be present. This is the first case report in the literature to suggest that dental abnormalities are part of the broad spectrum of clinical features of prune belly syndrome. Because the syndrome causes many serious medical problems, early diagnosis of abnormalities involving the primary and permanent dentitions are encouraged. Case presentation The authors report the clinical case of a 4-year-old Caucasian boy with prune belly syndrome. In addition to the triad of abdominal muscle deficiency, abnormalities of the gastrointestinal and urinary tracts, and cryptorchidism, a geminated mandibular right central incisor, agenesis of a mandibular permanent left incisor, and congenitally missing primary teeth (namely, the mandibular right and left lateral incisors) were noted. Conclusion This original case report about prune belly syndrome highlights the possibility that dental abnormalities are a part of the broad spectrum of clinical features of the syndrome. Therefore, an accurate intra-oral clinical examination and radiographic evaluation are required for patients with this syndrome in order to provide an early diagnosis of abnormalities involving the primary and permanent dentitions.
High Resolution Mass Spectrometry Elucidation of Captopril’s Ozonation and Chlorination By-Products  [PDF]
Frederico Jehár Oliveira Quint?o, Geraldo Célio Brand?o, Silvana de Queiroz Silva, Sérgio Francisco Aquino, Robson José de Cássia Franco Afonso
American Journal of Analytical Chemistry (AJAC) , 2017, DOI: 10.4236/ajac.2017.84020
Abstract: The article evaluated the degradation of the captopril in aqueous solution after ozonation and chlorination. The process was continuously monitored focusing on the identification, mass spectrometry and elucidation of its by-products by applying direct infusion and high performance liquid chromatography, electrospray ionization high resolution mass spectrometry, in the negative ion mode. The cytotoxicity of its by-products solutions were evaluated with 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. It was observed through that after 30 min of ozonation and chlorination, there was complete oxidation of captopril, i.e., 100% removal efficiency. At these conditions, the rate of mineralization, by total organic carbon, was only 7.63% for ozonation and 6.40% for chlorination, evidencing the formation of degradation by-products. Ten captopril by-products were identified and their respective chemical structures elucidations are proposed. The treated samples and their by-products were nontoxic to HepG2 cells by MTT assay.
Analysis of Dental Traumas and their Sequelae in the Primary Dentition: A Literature Review
Luciana Reichert da Silva Assun??o,Robson Frederico Cunha,Ant?nio Ferelle
Pesquisa Brasileira em Odontopediatria e Clínica Integrada , 2007,
Abstract: Introduction: Studies have shown that dental traumas in the primary dentition are common events that may result in sequelae that can compromise the affected primary tooth. In the literature, the frequency of dental trauma in the primary dentition is variable, while the age range, gender, etiological factor and the most affected teeth present similar prevalence. Regarding the most common type of trauma, differences may be found due to sampling criteria, such as the type of study and site of conduction of the study. Several sequelae may be observed in traumatized primary teeth, among which coronal discoloration, pulp necrosis, root canal obliteration and root resorption. Studies have pointed to the type of trauma and the age of the child at the moment of trauma as important factors that contribute to the occurrence of these sequelae.Purpose: The purpose of this article is to present a review of relevant studies referring to epidemiological factors and sequelae in traumatized primary teeth, providing to the reader an overview of dental trauma in the primary dentition.Conclusion: In conclusion, based on the analysis of the reviewed articles, it could be observed a direct relationship between the degree of severity of the dental traumas and the occurrence of sequelae in the affected primary teeth, emphasizing the importance of periodical follow up in these cases.
Luxation injuries in primary teeth: a retrospective study in children assisted at an emergency service
Assun??o, Luciana Reichert da Silva;Ferelle, Ant?nio;Iwakura, Maria Luiza Hiromi;Nascimento, Liliane Silva do;Cunha, Robson Frederico;
Brazilian Oral Research , 2011, DOI: 10.1590/S1806-83242011000200009
Abstract: the purpose of this study was to analyze luxation injuries in children between the ages of 0 and 5 years treated at an emergency service department. a total of 1,703 records, corresponding to a period of 10 years at the emergency center of the baby clinic at londrina state university, brazil, were analyzed. the age, gender, etiologic factors, type of injury, injured teeth, treatment and time interval between injury and treatment were determined for each patient. of the examined records, 409 patients met the study criteria and included a total of 679 injured teeth. statistical analyses were carried out using the chi-square test with the level of significance set at 5%. trauma incidence was higher in boys (57.0%) and in children less than two years of age (40.3%). falling while walking or running was the most predominant etiologic factor (37.7%), and the most prevalent type of injury was subluxation (32.6%). luxation injuries decreased with increasing age (p = 0.045). treatment usually occurred within the first 1-15 days and was significantly associated with the type of trauma (p = 0.041). "monitor only" was the treatment most frequently observed (74.0%). in conclusion, more luxation injuries were found in younger children, predominantly in boys. falls resulting from walking or running were the etiologic factor most observed, with subluxation as the most common type of trauma. treatment usually occurred within the first 15 days after the injury. despite the severity of these injuries, "monitor only" was the eligible treatment.
Weight and age at puberty and their correlations with morphometric measurements in crossbred breed Suffolk ewe lambs
Ferra, Janine de Campos;Cieslak, Silvia;Sartori Filho, Roberto;McManus, Connie;Martins, Carlos Frederico;Sereno, José Robson Bezerra;
Revista Brasileira de Zootecnia , 2010, DOI: 10.1590/S1516-35982010000100018
Abstract: the objective of this study was to identify and to correlate parameters that characterize puberty and estimate the age and weight of suffolk ewe lambs in mato grosso do sul. this study was carried out with twenty-two suffolk ewe lambs for 256 days. blood samples were collected from the jugular vein and centrifugated and the plasma were stored at -20°c until analysis of progesterone (p4) concentration by radioimmunoassay (ria). the morphometric measurements included: head length and width, body length, elbow height, chest perimeter, back-sternal diameter, croup length, width and height, cannon bone perimeter and shoulder and hip width, using a tape. the animals became pubertal when the plasma progesterone concentration was >1.0 ng/ml, at 34.1 ± 5.2 kg and 39.5 ± 8.5 weeks of age. meanwhile, the lambs that did not reach puberty (37.7 ± 11.4 weeks of age) were lighter. the morphometric measurements has medium to low correlations with age and weight at puberty.
The Matter-Antimatter Asymmetry Problem  [PDF]
Brian Albert Robson
Journal of High Energy Physics, Gravitation and Cosmology (JHEPGC) , 2018, DOI: 10.4236/jhepgc.2018.41015
Abstract: The matter-antimatter asymmetry problem, corresponding to the virtual nonexistence of antimatter in the universe, is one of the greatest mysteries of cosmology. According to the prevailing cosmological model, the universe was created in the so-called “Big Bang” from pure energy and it is generally considered that the Big Bang and its aftermath produced equal numbers of particles and antiparticles, although the universe today appears to consist almost entirely of matter rather than antimatter. This constitutes the matter-antimatter asymmetry problem: where have all the antiparticles gone? Within the framework of the Generation Model (GM) of particle physics, it is demonstrated that the asymmetry problem may be understood in terms of the composite leptons and quarks of the GM. It is concluded that there is essentially no matter-antimatter asymmetry in the present universe and that the observed hydrogen-antihydrogen asymmetry may be understood in terms of statistical fluctuations associated with the complex many-body processes involved in the formation of either a hydrogen atom or an antihydrogen atom.
Generation Model of Particle Physics with Excited Rishon States  [PDF]
Brian Albert Robson
Journal of High Energy Physics, Gravitation and Cosmology (JHEPGC) , 2019, DOI: 10.4236/jhepgc.2019.51006
Abstract: It is proposed that the Generation Model (GM) of particle physics, which describes the elementary particles, the six leptons, the six quarks and the three weak bosons, of the Standard Model (SM) as composite particles in terms of three kinds of rishons and their antiparticles may be mimicking a simpler model, employing only two kinds of rishons and their antiparticles.
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