Determinação eletroanalítica e cromatográfica do corante solvente azul 14 em amostras de combustíveis

Métodos comparativos foram desenvolvidos para detectar e quantificar o corante solvente azul 14 (SA-14) em amostras de combustíveis. O método eletroanalítico foi baseado na técnica de voltametria de onda quadrada (VOQ) com detecção em +0,60 V vs. Ag/AgCl sobre o eletrodo de carbono vítreo, usando tampão Britton-Robinson e N, N-dimetilformamida (1:1, v/v) como eletrólito suporte. Para metodologia, envolvendo a cromatografia líquida de alta performance (CLAE) foi empregada uma fase móvel composta de acetonitrila e cloreto de lítio (85:15, v/v) e a detecção eletroquímica foi realizada em um potencial de oxidação em +0,65 V vs. Ag/AgCl. Sob as melhores condições de trabalho curvas de calibração foram obtidas, para ambos os métodos, as quais foram lineares na faixa de concentração de 5,0×10 -7 a 6,0×10 -6 mol L-1 (VOQ) e 8,0×10 -8 a 3,0×10 -6 mol L-1 (CLAE). Os métodos foram aplicados para quantificar o corante em amostras de álcool e querosene após um simples processo de extração em fase sólida com resultados de recuperação satisfatórios.

Efeito da limpeza pós-condicionamento e do tratamento térmico do silano na resistência de união de um cimento resinoso à cerâmica

Pós-graduação em Odontologia - FOA

Avaliação histológica de estratégias de engenharia tecidual para a terapia endodôntica

Pós-graduação em Ciência Odontólogica - FOA

Influência de três tratamentos de superfície para cerâmicas a base de zircônia na resistência adesiva e no comportamento à fadiga do material

Pós-graduação em Odontologia Restauradora - ICT

Quantificação de endotoxinas e sua relação com sinais / sintomas e volumetria da lesão periapical e do canal radicular em dentes com infecção endodôntica primária

Pós-graduação em Odontologia Restauradora - ICT

Fotocromismo e luminescência de compostos a base de tungstênio e íons terras raras trivalentes via síntese hidrotérmica

Pós-graduação em Química - IQ

Pré-tratamento do bagaço de cana-de-açúcar, hidrólise e sua caracterização química e estrutural, visando a produção de etanol de segunda geração

Pós-graduação em Biotecnologia - IQ

Cárie oculta extensa: relato de caso clínico

The pattern of caries lesions has been modified over decades. If the presence or absence of a caries lesion is based upon only a visual examination, its diagnosis might become underestimated since dentinal lesions underneath non cavitated or minimally demineralized enamel is highly frequent in dental clinics. The aim of this paper is to report a clinical case of a child with an upper molar with questionable occlusal aspect, presenting asymptomatic pulpal hyperplasia on the distolingual pit. Periapical radiographic examination was essential for diagnosing hidden caries and elaborating the treatment plan. As part of the approach, removal of the decayed tissue and pulpotomy with calcium hydroxide were performed. The association of an accurate visual examination to an adequate oral radiographyis is extremely important in cases which the presence of hidden caries is doubtful. As a result, an early diagnosis and the reduction of more invasive interventions related to the oral health care of pediatric patients can be achieved as well.

Reparo periapical de dentes tratados endodonticamente submetidos a movimentação ortodôntica

The relationship of Orthodontics and Endodontics is being clarified with the development of evidence-based dentistry. However, few studies have reported the repair of periapical lesions with orthodontic treatment. Therefore, the aim of this study was to evaluate the available evidence on periapical repair of endodontically treated teeth during orthodontic movement. The strategy used was the electronic search with keywords and criteria including studies published up to July 2011. It was also carried out qualitative assessment of the articles methodology. Although a significant number of studies have reported this topic, only two filled the criteria for inclusion in this systematic review. The results obtained in the literature suggest that orthodontic treatment should be interrupted to perform endodontic treatment. During this therapy, the use of root canal dressing based on calcium hydroxide for at least 14 days, and sealer with adequate biological property are indicated. After this phase, orthodontic movement of the endodontically treated teeth can be resumed without waiting period.

Hipersensibilidade dentinária cervical: em busca de um tratamento eficaz

The knowledge of the etiology of any disease or condition is paramount to a safe and effective treatment. This literature review aims to show some options to treat dentine hypersensitivity (HSDC). The loss of cervical enamel and cementum exposure of tubules leads to a painful condition and patient discomfort, called HSDC. This loss of tooth structure occurs due to formation of cervical lesions in cases of gingival recession, abrasion, erosion, or abfraction by the association of two or more factors. Some treatments are not effective, but there are effective therapies, such as: application of ferric oxalate, potassium oxalate, potassium nitrate, fluoride varnish, solutions of calcium phosphate, adhesives and Bonding procedures. Therefore, the identification and removal of etiological factors is essential to successful treatment of HSDC normally associated to tubules obliterate and consequent reduction of fluid motion within the dentin.

Avaliação da capacidade de vedamento e pH do tampão apical com cimento Portland branco acrescido de radiopacificadores convencionais

The Portland cement has shown similar biological properties to calcium hydroxide, but its radiopacity is lower. Therefore, the addition of materials that minimize this deficiency should be considered. OBJECTIVE: To evaluate the apical sealing ability and pH of a white Portland cement added of several radiopacifying agents. MATERIAL AND METHODS: Forty bovine roots with incomplete apices were selected, and the foraminal openings were standardized to PM 720G bur. After the external root sealing, an apical intracanal barrier 10.0 mm thick was executed with the white Portland cement powder, pure or added of a radiopacifying agent (iodoform, zinc oxide or bismuth subnitrate), and distilled water (0.37 mL). The apical roots were immersed 24h in water in humid atmosphere, and after that they were immersed 24h in 2% Rhodamine B, under vacuum. In sequence, the roots were longitudinally sectioned, the root fragments were photographed, the images were digitalized and the apical infiltration was measured by the Image Tool program. The pH solutions were also evaluated, in 24h and 48h and 7 and 30 days. Data were submitted to Anova test. RESULTS: The zinc oxide solution has the lowest apical infiltration in relation to the other groups (p < 0.05). The pH behavior varied during the analysis, and in the period of 24h all groups showed the highest values (p < 0.05). CONCLUSION: The type of radiopacifying agent used interferes in the sealing ability of the apical barrier, and zinc oxide showed to be the most beneficial one. The pH varies according to the period of analysis, and the highest values were obtained in the first 24h (p < 0.05).

Avaliação do pH, da solubilidade e da infiltração marginal em retrobturações com o Sealer 26 puro ou acrescido de iodofórmio

Sealer 26® cement contains bisphenol epoxy resin associated with calcium hydroxide, presenting smaller radiopacity than other endodontic cements. Aiming to improve this property, iodoform has been added in its composition. However, this addition's possible changes in physical and chemical properties still need to be studied. OBJECTIVE: To evaluate the apical sealing ability, solubility, and pH of Sealer 26® alone or with iodoform, at several proportions. MATERIAL AND METHODS: Three experimental mixtures of Sealer 26®, alone or with iodoform, were prepared and subjected to solubility test. Additionally, these combinations were inserted into polyethylene tubes and immersed in distilled water, and, their pH was evaluated after 24-h and 7-day periods. Subsequently, forty roots of extracted lower incisors subdivided into four groups of 10 specimens each, were retrograde filled with one of the previously described mixtures and gutta-percha points. The roots were immersed in Rhodamine B, under vacuum, for 72 hours. After this period, the specimens were longitudinally sectioned, root fragments photographed, these images scanned, and apical infiltration measured by Image tool software. The obtained data were subjected to statistical analysis, at a significance level of 5%. RESULTS: Marginal leakage and solubility tests did not show any difference among the experimental groups (p > 0.05). pH analysis was only statistically different at 24-h period and between Sealer 26® alone and 1.1g iodoform group (p < 0.05). CONCLUSION: The presence of iodoform in Sealer 26®, at the used proportions, did not alter the solubility, apical marginal leakage and pH properties of the original cement.

Resolução por retratamento não cirúrgico de dente com lesão periapical: relato de caso clínico

The development and maintenance of periapical lesion occurs as a result of bacterial infection of the root canal system. Faced with the failure of endodontic treatment, retreatment is the first option with great potential for success, when performed with proper disinfection of the root canal system. Case report: Patient aged 39 years needing dental care show at clinical examination moderate gingival bleeding in the region of tooth 22 and the presence of radiographic periapical bone rarefaction due to unsatisfactory endodontic treatment. It was indicated the endodontic retreatment. We performed procedures to remove the filling material, root canal preparation using manual and mechanical techniques and completion with the use of root canal medication based on calcium hydroxide. After root canal filling, clinical and radiographic success were demonstrated for the case. Conclusion: We conclude that the non-surgical retreatment with disinfection and proper use of medication to the base of calcium hydroxide promoted success after outcome monitoring for 2 years and 8 months (AU)

Biocompatibility of Intracanal Medications Based on Calcium Hydroxide

The aim of this study was to evaluate the rat subcutaneous tissue reaction to calcium hydroxide-based intracanal medicaments, UltraCal XS (calcium hydroxide, barium sulphate, aqueous matrix), Hydropast (calcium hydroxide, barium sulphate, and propyleneglycol), and Calen (Calcium hydroxide, zinc oxide, colophony, and polyethyleneglycol), used as a control. Methods. Forty-eight rats (Rattus Norvegicus Holtzman) were distributed in three groups: Calen, UltraCal XS, and Hydropast. Polyethylene tubes filled with one of the medicaments were implanted in the dorsal subcutaneous. After 7 and 30 days, the implants were removed and the specimens were fixed and embedded in paraffin. Morphological and quantitative analyses were carried out in the HE-stained sections. The numerical density of inflammatory cells in the capsule was evaluated and statistical analyses were performed (P>/0.05). Results. At 7 days, all materials induced an inflammatory reaction in the subcutaneous tissue adjacent to the implants. In all groups, a significant reduction in the number of inflammatory cells and giant cells was verified in the period of 30 days. Conclusion. These results indicate that the calcium hydroxide-based medicaments evaluated present biocompatibility similar to Calen.