Abstract Objective: To compare the clinical effect of two desensitizing agents used before the application of a bleaching gel based on 35% hydrogen peroxide (HP). Material and Methods: 30 patients were selected, and two desensitizing agents with different mechanisms of action were applied: Fluorine Neutral 2% (FN), which acts by blocking dentinal canaliculi while Potassium Nitrate 5% with 2% Sodium Fluoride (PN/SF) that acts in nerve transmission and blockade. Desensitizers were used before the application of 35% HP. For whitening, three clinical sessions were performed, with an interval of seven days, with three applications of the bleaching gel for 15 minutes, totaling 45 minutes/session. Tooth sensitivity (TS) was assessed with the numerical analog scale, and a spectrophotometer was used to obtain the color variation (ΔE). ΔE were submitted to ANOVA and Tukey test (p<0.05), and TS data were submitted to a two-way ANOVA analysis. Results: For sensitivity experience, the Tukey test indicated differences between PN/SF and the placebo I, but there was no statistically significant difference between FN and the placebo II. The TS was lower when the desensitizing gel was used during the bleaching procedure compared to after treatment, regardless of the desensitizing agents. Conclusion: PN/SF before in-office tooth bleaching can reduce TS intensity, and the use of desensitizing gel before bleaching did not affect the bleaching efficacy.

Abstract To analyze the biocompatibility of the scaffold produced from a natural polymer derived from castor oil through hemolytic activity and antimicrobial activity, to enable the clinical application. Three in vitro tests were performed: Hemolytic activity test - Polymer partially dissolved in contact with blood agar; Hemolytic activity test in sheep's blood - Polymer extract with red blood cells solution; Antimicrobial activity test - Solid polymer in direct contact with E. Coli and S. Aureus. For hemolytic tests, none of the samples showed hemolysis. Negative hemolytic activity is a good indicator, as the maintenance of the blood clot in the area of the lesion is essential for the formation of new tissue. For the antimicrobial activity test, no significant activity was observed against the bacteria used. The polymer is not toxic to red blood cells, being viable for clinical application as a matrix for tissue regeneration.

Abstract To analyze the surface topography and mechanical properties of a polyurethane derived from castor oil reinforced with hydroxyapatite (PU–HA) for bone fixation. The surface analysis was performed by Scanning Electron Microscopy (SEM) and the mechanical properties by Vickers microhardness and tensile tests. The SEM images showed that the PU surface presented important characteristics for materials intended for bone fixation, such as an irregular and porous surface. The analysis showed a surface with alternating areas with depressions and elevations of approximately 80±100 µm, presence of pores of 12 µm in size. The microhardness analysis showed values of 0.42±1.01 HV for PU–HA plates, lower in relation to the poly lactic-co-glycolic acid (PLGA) plate (control group). The elastic modulus and ultimate tensile strength of 317.4 MPa, and 35.57 MPa for PLGA sample, 1.187 MPa, and 0.29 MPa for PU–HA sample. The PU produced showed good surface properties, however demands better mechanical properties.

Abstract To produce polysaccharide-based hydrogels and cerium (Ce3+) doped hydroxyapatite plus chitosan and collagen to enable future applications in the treatment of joint degeneration. Hydrogel production and characterization were performed with Fourier transform infrared spectroscopy (FTIR), thermogravimetry analysis (TGA) and cytotoxicity testing with MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide]. A final biomaterial composition was Kelcogel® Gelana (58%), chitosan (22.3%), Ce3+ doped hydroxyapatite (10.7%) and bovine collagen (9%), or selected aspect material gelatinous physical color with whitish color and can be injected. The biomaterial composition was proven in the FTIR and TGA, which also provided the maximum supported temperature. In the MTT assay, despite the reduction in viability of the experimental group compared to the control group, cell viability remained approximately 90%. In the FTIR and TGA tests, the material composition was proven. The material does not present cytotoxic behavior for the MTT test, being an alternative for the treatment of joint diseases.

Resumo Introdução Com o intuito de se evitar as tensões geradas durante a contração de polimerização das resinas compostas, foram desenvolvidas as resinas compostas de baixa contração de polimerização. Objetivo Avaliar a resistência à microtração em cavidades classe I restauradas com tratamento ácido do ângulo cavo superficial e resina composta indicada para dentes posteriores. Material e método Foram selecionados 48 molares hígidos que foram divididos em 6 grupos (n=8), sendo que 3 desses tiveram o esmalte cavo superficial condicionado com ácido fosfórico a 35%. Os dentes foram restaurados com o sistema adesivo Clearfil SE Bond e as resinas compostas Filtek Z350 XT, Empress Direct e Charisma Diamond, fotoativadas por 40 segundos. Após 24 horas, os dentes foram levados para máquina de corte, na qual foram realizados cortes no sentido vestíbulo-lingual e no sentido mésio-distal obtendo – se palitos de 0,9×0,9 mm que foram levadas para a máquina de ensaio universal para a realização do teste de microtração. Para análise estatística foi realizado análise de variância e teste de Tuckey (p < 0,05). Resultado Não houve diferença estatística significante entre os grupos avaliados. Conclusão O condicionamento ácido do ângulo cavo superficial não influenciou no desempenho das restaurações provavelmente devido ao sistema adesivo utilizado.

Abstract Introduction To prevent the shrinkage stresses produced during polymerization, composite resins of low polymerization shrinkage were developed. Objective To evaluate the microtensile bond strength in class I cavities restored by acid-etching the cavosurface angle and with composite resins indicated for posterior teeth. Material and method 48 healthy molars were selected and divided into six groups (n = 8), considering that the cavosurface enamel of three groups was etched with 35% phosphoric acid. The teeth were restored with the Clearfil SE Bond adhesive system and Filtek Z350 XT, Empress Direct, and Charisma Diamond composite resins, which were light-cured for 40 seconds. After 24 hours, the teeth were taken to a cutting machine, which produced sections in the buccolingual and mesiodistal directions. This resulted in toothpicks of 0.9×0.9 mm that were taken to the universal testing machine for the microtensile bond strength test. Statistical analysis was performed with ANOVA and Tukey’s test (p < 0.05). Result There was no statistically significant difference between the groups evaluated. Conclusion Acid-etching the cavosurface angle did not affect the performance of restorations, probably due to the adhesive system used.

Abstract Objective To clinically assess the effect of desensitizing gels and dentifrices on the reduction in pain sensitivity and color variation during tooth bleaching. Methodology A total of 108 volunteers were randomly separated into the following groups of n=12: GT/S-glycerine and thickener/sucralose; NF/S-potassium nitrate and sodium fluoride/sucralose; NA/S-potassium nitrate and arginine/sucralose; GT/AC-glycerine and thickener/arginine and calcium carbonate; NF/AC-potassium nitrate and sodium fluoride/arginine and calcium carbonate; NA/AC-potassium nitrate and arginine/arginine and calcium carbonate; GT/PN-glycerine and thickener/potassium nitrate; NF/PN-potassium nitrate and sodium fluoride/potassium nitrate; and NA/PN-potassium nitrate and arginine/potassium nitrate. Sensitivity was assessed with the numerical analogue scale, and color variation (ΔE) was measured with a spectrophotometer. The sensitivity values obtained were subjected to a multivariate analysis of variance (MANOVA) and color variation values were subjected to a randomized analysis of variance (p<0.05). Results The NF/AC, NA/AC, NF/PN, and NA/PN groups presented lower sensitivity values and reduced sensitivity compared to those of the other groups throughout the clinical sessions. None of the groups showed sensitivity at the 24-week assessment. Statistically, no significant difference were observed in the color values among the groups four weeks after the beginning of bleaching (p=0.074). Additionally, the color assessment of all groups was statistically similar four weeks (p=0.084) and 24 weeks (p=0.118) after the beginning. Conclusion Our results indicate that adding NF/S, NA/S, NF/AC, and NA/AC desensitizers to tooth bleaching protocols reduces pain sensitivity without affecting its effectiveness.

Resumo Objetivo Avaliar o conhecimento e conduta dos Cirurgiões-Dentistas (CD) da Estratégia Saúde da Família (ESF) sobre o Tratamento Restaurador Atraumático (ART). Material e método A amostra foi censitária e todos os CD da ESF da zona urbana da cidade de Teresina – PI foram visitados em seus locais de trabalho e convidados a participar do estudo. Questionários autoaplicáveis foram utilizados como técnica de coleta de dados. Para as análises estatísticas aplicou-se o teste qui-quadrado com nível de significância de 5% e o teste de associação linear. Resultado Participaram do estudo 183 profissionais, a maioria do sexo feminino (71,0%), na faixa etária de 20 a 39 anos (49,2%), com vinte ou mais anos de formados (45,9%), que tem apenas o serviço público como vínculo empregatício (70,5%), e especialização em área clínica (44,3%). A maioria acredita no ART (82,7%) e a realiza (95,8%), apenas no serviço público (58,9%). O conhecimento individual dos profissionais sobre ART foi mensurado e a maioria apresenta informações corretas sobre o tratamento. Houve associação significativa do autorrelato de conhecimento de ART com a faixa etária, o tempo de formado e a titulação dos participantes. A avaliação do nível de conhecimento teve associação significativa com a faixa etária e tempo de formado. Conclusão A maioria dos Cirurgiões-Dentistas da Estratégia Saúde da Família de Teresina, Piauí, Brasil possui um bom conhecimento e conduta positiva em relação ao ART, mas necessita de aprimoramento com relação à técnica e sua correta indicação.

Abstract Objective To evaluate the knowledge and conduct of dentists of the Public Health System (Family Health Strategy – FHS) regarding Atraumatic Restorative Treatment (ART). Material and method A census survey was conducted and all FHS dentists from the urban area of the city of Teresina, Piauí, Brazil were visited in their workplaces and invited to participate in this study. Data collection was carried out between July and October, 2014 through self-administered questionnaires. For statistical analysis the chi-square test with a significance level of 5% and the linear association test were applied. Result One hundred and eighty-three professionals participated in the study (with a response rate of 89.7%), mostly women (71.0%), aged twenty to thirty-nine years (49.2%), with twenty or more years’ experience since graduation (45.9%), working only in the public service (70.5%), and with expertise in the clinical area (44.3%). Most of them believe in ART (82.7%) and 95.8% of them apply it (of those, 58.9% apply it only in public service). The professionals’ individual knowledge of ART was measured and most of them have correct information regarding the treatment. The knowledge level evaluation was significantly associated with age and time since graduation (p<0.05). Conclusion Most of the dentistsworking in the public health system of Teresina, Piauí, Brazil have a good knowledge of and show positive behavior towardentists ART, but improvement is needed regarding the technique and its correct indication.