Resumo Os objetivos deste estudo clínico foram avaliar a alteração de cor - ΔE (baseada em espectrofotometria e análise visual) e luminosidade - L* (baseada em espectrofotometria) da superfície do esmalte dentário (após tratamento ortodôntico) ao redor da área onde os braquetes ortodônticos foram fixados, com base em diferentes materiais de cimentação, como resina (grupo R) e cimento de ionômero de vidro modificado por resina (grupo RMGIC). Estudo boca dividida foi inicialmente composto por 14 pacientes. Os braquetes ortodônticos foram fixados nos incisivos centrais superiores com resina ou RMGIC. A cor da superfície vestibular de cada dente foi mensurada por espectrofotometria e avaliada por exame visual antes do processo de fixação dos braquetes. Quatro indivíduos foram excluídos durante o acompanhamento; assim, 10 pacientes foram avaliados (n=10). Os braquetes foram removidos após 12 meses de tratamento ortodôntico, a mensuração da cor do dente e o exame visual foram realizados novamente, e o Índice de Remanescente do Adesivo (IRA) também foi mensurado. Os resultados ΔE e L* foram submetidos ao teste t de Student e à análise de variância para medidas repetidas, respectivamente (α=0.05). Os dados do ARI foram analisados em porcentagens. Houve diferença estatisticamente significativa no ΔE entre os grupos; o grupo R apresentou valores estatisticamente maiores de L* após o tratamento ortodôntico. O IRA 2 e 3 prevaleceu no grupo RMGIC, enquanto o grupo R apresentou 0 e 1. Após o tratamento ortodôntico, o grupo RMGIC apresentou menores alterações no ΔE e o aumento da escala branca foi observado na superfície do esmalte ao redor da área onde os braquetes foram fixados no grupo R. A análise visual não mostrou mudança de cor nos dentes avaliados.

Abstract The aims of this clinical study were to evaluate the Color change - ΔE (based on spectrophotometry and visual analysis) and luminosity - L* (based on spectrophotometry) of dental enamel surface (after orthodontic treatment) around the area where orthodontic brackets were fixed, based on different cementing materials such as a resin (R group) and resin-modified glass ionomer cement (RMGIC group). The split-mouth study initially comprised 14 patients. Orthodontic brackets were fixed to the upper central incisors with resin or RMGIC. The color of the buccal surface of each tooth was measured through spectrophotometry and visual examination before the bracket-fixation process. Four individuals were excluded during the follow-up; thus 10 patients were evaluated (n=10). Brackets were removed after 12 months of orthodontic treatment, tooth color measurement and visual examination were performed again, and Adhesive Remaining Index (ARI) was also measured. ΔE and L* results were subjected to Student's t-test and by repeated-measures analysis of variance, respectively (α=0.05). ARI data were analyzed in percentages. There was statistically significant difference in ΔE between groups; the R group showed statistically higher values of L* after orthodontic treatment. ARI of 2 and 3 prevailed in the RMGIC group, whereas the R group presented 0 and 1. After orthodontic treatment, the RMGIC group presented smaller changes in ΔE, and the increase in the white scale was observed on the enamel surface around the area where brackets were fixed in the R group. The visual analysis did not show color change on the evaluated teeth.

Aim Assessing the intracoronal bleaching effectiveness of an experimental chlorine dioxide product, based on the walking bleach technique. Methods Extracted bovine incisors were artificially stained with bovine blood and filled with zinc phosphate cement at cementoenamel junction level. Teeth were divided into 3 groups (n=10): (SP) sodium perborate added with distilled water, (CD) chlorine dioxide and (C) control – dry cotton inserted into the pulp chamber. Bleaching agents were used at 0, 7 and 14 days. VITA Easyshadetm (∆Eab) was used to analyze tooth color at the 7th, 14th and 21st days, based on the CIE2000 system. Data were analyzed through ANOVA and Tukey’s test. Results There were no statistically significant differences in Δb, ΔE, ΔE00 and ΔWID between CD and the control group. These parameters have shown significant differences between CD and SP, which differed from the control. However, they did not show significant differences either in the control group or in CD at the 7th, 14th and 21st days. Values recorded for SP at the 7th day differed from those recorded at the 14th and 21st days. Δa has shown differences within the same group at the 7th, 14th and 21st days. There was no difference between groups, when they were compared at the same day (7th and 14th). The control group differed from SP at the 21st day. CD did not differ from the other two groups. ΔL did not show differences between groups and times. Conclusion Stabilized chlorine dioxide (0.07%, at pH 3.5) should not be used as intracoronal bleaching agent along with the walking bleach technique.

Resumo Os objetivos deste estudo in vivo foram avaliar o efeito da colagem com cimento de ionômero de vidro modificado por resina (CIVMR) e a rugosidade da superfície do esmalte antes e após a remoção dos braquetes colados com compósito ou CIVMR em incisivos centrais superiores. Quinze pacientes ortodônticos foram selecionados para o estudo. Para cada paciente, os dentes foram lavados e secos, e os braquetes colados com compósito (Transbond XT) e CIVMR (Vitremer Core Buildup / Restorative). Ao término do tratamento ortodôntico, os braquetes foram removidos. As réplicas dentais foram confeccionadas em resina epóxica nas condições iniciais (antes da colagem) e após o polimento com sistema de discos de óxido de alumínio. O índice de remanescente adesivo (IRA) e a rugosidade da superfície foram mensurados nas réplicas dentais e os dados foram avaliados estatisticamente por Mann-Whitney e teste t pareado, respectivamente. Não ocorreu descolagem de braquetes durante os períodos de tratamento dos pacientes. Verificou-se que os valores do IRA dos dois incisivos centrais superiores foram semelhantes (p = 0,665). Para ambos os materiais de colagem, o valor de IRA predominante foi 3. Após o polimento, a rugosidade da superfície do esmalte foi semelhante nos grupos compósito (0,245 μm) e CIVMR (0,248 μm) (p = 0,07). Em ambos os grupos, os valores de rugosidade da superfície do esmalte foram significativamente menores após o polimento em comparação com a condição inicial (p <0,001). CIVMR promoveu eficiência na colagem de braquetes sem falhas durante o tratamento; a escolha dos materiais compósito ou CIVMR não foi um fator que influenciou na rugosidade da superfície do esmalte, porém, o polimento levou a superfícies mais lisas do que as encontradas no início do tratamento.

Abstract The aims of this in vivo study were to evaluate the effect of bonding with resin-modified glass ionomer cement (RMGIC) and to assess enamel surface roughness before and after the removal of brackets bonded with composite or RMGIC from the maxillary central incisors. Fifteen orthodontic patients were selected for the study. For each patient, the teeth were rinsed and dried, and brackets were bonded with composite (Transbond XT) and RMGIC (Vitremer Core Buildup/Restorative). At the conclusion of orthodontic treatment, their brackets were removed. Dental replicas were made of epoxy resin in initial conditions (before bonded) and after polishing with an aluminum oxide disc system. Adhesive remnant index (ARI) and surface roughness was measured on the dental replicas and data were evaluated statistically by Mann-Whitney and paired t-test, respectively. No bracket debonding occurred during patients’ treatment periods. It was verified that the ARI values of the two maxillary central incisors were similar (p = 0.665). For both bonding materials, the ARI value of 3 was predominant. After polishing, surface roughness was similar in the composite and RMGIC groups (0.245 μm and 0.248 μm, respectively; p = 0.07). In both groups, enamel surface roughness values were significantly lower after polishing compared with the initial condition (p < 0.001). RMGIC promoted efficiency in cementing brackets without fail during treatment; the choice of composite or RMGIC materials was not a factor that influenced the roughness of the enamel surface, however, polishing led to smoother surfaces than those found at the beginning of the treatment.

Resumo Este estudo avaliou a composição química e microdureza do esmalte humano tratado com solução de Derivados da Matriz do Esmalte (EMD) e a resistência de união entre compósito e este esmalte. Trinta amostras de esmalte humano foram aleatoriamente divididas em três grupos: Esmalte Intocado (UE), Esmalte Desmineralizado (DE) e Esmalte Desmineralizado Tratado com EMD (ET). Os grupos DE e ET foram submetidos a desafio ácido e ET tratado com EMD (O EMD foi aplicado diretamente sobre esmalte condicionado e deixado por 15 minutos). Amostras de cada grupo (n = 4) tiveram composição química avaliada através de espectroscopia no infravermelho por transformada de Fourier com reflectância total atenuada (FTIR-ATR). A microdureza Knoop das amostras de esmalte de cada grupo (n=10) foi mensurada. Para a resistência ao microcisalhamento, as amostras foram condicionadas por 30 s, o adesivo aplicado e foto-ativado por 10 s. Duas matrizes plásticas (1 mm de comprimento) foram posicionadas sobre as amostras, preenchidas com compósito Filtek Z350 XT e foto-atiavadas por 20 s cada. As matrizes foram removidas e a resistência ao microcisalhamento de cada grupo (n=10) foi testada. Os dados foram submetidos ao teste de Kruskal-Wallis (para análise da microdureza), à análise de variância e ao teste de Tukey (para análise da resistência ao microcisalhamento); (α=0.05). Os resultados do FT-IR mostraram fosfato (indicador de hidroxiapatita) na banda entre 900-1200 cm-1 nos grupos UE e ET, diferentemente do grupo DE. Análises de microdureza e microcisalhamento demonstraram resultados estatisticamente superiores para os grupos UE e ET quando comparados ao DE. A aplicação de EMD ao esmalte desmineralizado parece ter remineralizado o esmalte; assim, a microdureza e a resistência de união foram semelhantes entre os grupos UE e ET.

Abstract This study evaluated the chemical composition and microhardness of human enamel treated with an Enamel Matrix Derivative (EMD) solution, and the bond strength between composite resin and this enamel. Thirty human enamel samples were randomly divided into three groups: Untouched Enamel (UE), Demineralized Enamel (DE) and Demineralized Enamel Treated with EMD (ET). DE and ET groups were subjected to acid challenge and ET treated with EMD (EMD was directly applied over conditioned enamel and left for 15 min). Samples from each group (n=4) had chemical composition assessed through to attenuated total reflectance Fourier transform infrared (ATR-FTIR). Knoop microhardness of enamel samples from each group (n=10) was measured. For the microshear bond strength, the samples were etched for 30 s, and the adhesive was applied and cured for 10 s. Two matrixes were placed on the samples, filled with Filtek Z350 XT composite and cured for 20 s, each. The matrix was removed, and the microshear bond strength of each group (n=10) was tested. Data were subjected to Kruskal-Wallis test (for microhardness), to analysis of variance and to Tukey’s test (for microshear bond strength); (α=0.05). FTIR results have shown phosphate (hydroxyapatite indicator) in 900-1200 cm-1 bands in the UE and ET groups, which were different from the DE group. Microhardness and microshear analyses recorded higher statistical values for the UE and ET groups than for DE. EMD application to demineralized enamel seems to have remineralized the enamel; thus, the microhardness and bond strength was similar between UE and ET groups.

Resumo Levantes de mordida posterior são dispositivos para o tratamento ortodôntico confeccionados com resinas compostas ou materiais ionoméricos. Cuidado com a remoção destes se faz necessário para proteção da superfície dentária; para tanto, materiais pigmentados são preferidos por proporcionar melhor visualização. Este estudo propõe uma técnica de pigmentação experimental de resinas compostas convencionais, avaliando a resistência ao microcisalhamento (µ-SBT) na interface de união da resina experimental e superfície de esmalte dental e comparando-a com materiais comercialmente disponíveis para a confecção de levantes de mordida. Quarenta e oito superfícies de dentes humanos foram selecionadas aleatoriamente e divididos em quatro grupos (n=12), de acordo com o material adesivo utilizado: C (Controle, resina composta convencional); P (pigmentação experimental da resina composta convencional); UBL (Ultra Band Lok®); OB (Ortho Bite®). Microcilindros foram preparados para cada tipo de compósito utilizando uma matriz de silicone. As amostras foram mantidas em água destilada por 24h a 37°C, antes da realização do µ-SBT. Os padrões de fratura foram avaliados através de uma lupa estereoscópica com magnificação de 10x. ANOVA com pós teste de Fisher e teste de Dunnett foram utilizados para avaliar os dados. As médias obtidas do µ-SBT ± desvio padrão (MPa) foram: C (39.98a±13.0), P (40.09a± 14.3); UBL (33.26ab±8.6); OB (28.70b±5.5). O tipo de fratura mais prevalente foi a adesiva (80.4%). Além disso, não foi observada correlação estatisticamente significante entre os valores de resistência de união e os padrões de fratura. A técnica de pigmentação experimental não alterou os resultados de µ-SBT da resina composta convencional e mostrou adesividade semelhante à dos compósitos modificados por poliácidos utilizados neste estudo.

Abstract Posterior build-ups are auxiliary devices to orthodontic treatment which are made with resin-based or glass ionomer composites. Their removal requires care to protect the tooth surface, therefore, pigmented materials are preferred for a better visualization. This study proposed a pigmentation experimental technique of a regular composite resin, evaluating the microshear bond strength test (µ-SBT) of this experimental pigmented resin and comparing with a blue-colored polyacid-modified composite resin, used for posterior buildups. Forty-eight buccal and lingual surfaces of human teeth were used and randomly divided into 4 groups (n=12). The groups were divided into: C (control), regular composite resin; P, regular composite resin pigmented; UBL, Ultra Band Lok™; OB, Ortho Bite™. The composites were bonded using a matrix to obtain microcylinders and prepared for each experimental groups. The samples were then stored in distilled water for 24h at 37°C followed by a µ-SBT. The types of bond failures were evaluated using a stereoscopic magnifying glass (10×). The data were analyzed by ANOVA with Fisher post hoc and Dunnett´s test. Means of µ-SBT± standard deviation (MPa) were: C (39.98a±13.0), P (40.09a± 14.3); UBL (33.26ab±8.6); OB (28.70b±5.5). The most prevalent type of failure was adhesive (80.4%). Further, was not observed a statistically significant correlation between the bond strength values and failure patterns. The pigmentation of a commercially available resin did not alter the µ-SBT and exhibited similar adhesiveness as a polyacid-modified composite resin.

Resumo Este estudo avaliou a taxa de decomposição (DR), pH, alteração da cor do esmalte (∆E) e índice de clareamento (DWI) promovido por agentes clareadores caseiros e de consultório. A superfície do esmalte foi submetida a (n=10): agentes caseiros (10%, 15%, 20% de peróxido de carbamida - CP e 6% de peróxido de hidrogênio - HP) e três agentes a base de HP a 35% comirradiação por luz (LED, laser e halógena) ou sem tratamento (controle). A DR e pH dos agentes foi mensurada após 0, 2, 4, 6 e 8h (agentes caseiros) e após 5, 15, 20, 30 e 40 min (agentes de consultório). Parâmetros de cor (L*, a*, b*, DE e DWI) foram determinados inicialmente e após clareamento. Os dados da DR, pH, L*, a*, b* foram analisados por ANOVA um fator (agentes caseiros) ou dois fatores (agentes de consultório) de medidas repetidas e teste Tukey. ΔE e DWI por ANOVA um fator (agentes caseiros) e dois fatores (agentes de consultório) e teste Tukey. A DR dos agentes clareadores caseiros foi similar após 6 e 8 h (p>0.05), com pH próximo ao neutro (6,5 a 6,9 - CP) ou ácido (5,9- HP 6%). De 4 a 8 h, a ∆E foi maior para CP 15% e 20% comparado ao CP 10% (p<0.05). Após 40 min, a DR dos agentes HP 35% foi similar e todos exibiram ∆E significante em uma aplicação (p<0.05), independente da aplicação de luz. DWI indicou efeito clareador, sem diferenças entre os grupos (p>0.05). Um agente HP 35% exibiu pH alcalino, e os outros, pH<5.5. Os agentes clareadores caseiros poderiam ser aplicados por 2 h (15%, 20% CP e 6% HP) e 4 h (CP 10%), e os agentes clareadores de consultório, até 40 min em uma aplicação, sem luz.

Abstract This study evaluated the decomposition rate (DR), pH, enamel color alteration (DE) and whiteness index (DWI) promoted by at-home and in-office bleaching. Enamel surface was submitted to (n=10): at-home (10%, 15%, 20% carbamide peroxide - CP, 6% hydrogen peroxide -HP) and three 35% HP agents with light irradiation (LED, laser, and halogen) or no treatment (control). The DR and pH of agents were measured after 0, 2, 4, 6 and 8 h (at-home) or after 5, 15, 20, 30 and 40 min (in-office). Color parameters (L*, a*, b*, DE, DWI) were determined at baseline and after bleaching. DR, pH, L*, a*, b* data were analyzed by one-way (at-home) or two-way (in-office) repeated measures ANOVA and Tukey test. DE and DWI, by one-way (at-home) or two-way (in-office) ANOVA and Tukey test. DR of at-home agents was similar after 6 and 8 h (p>0.05), with pH close to neutral (6.5 to 6.9, CP) or acid 5.9 (6% HP). From 4 to 8 h, DE was higher for 15% and 20% CP compared with 10% CP (p<0.05). After 40 min, DR of 35% HP agents was similar and all exhibited significant DE in one application (p<0.05), regardless light irradiation. DWI indicated whitening effect with no differences among groups (p>0.05). One 35% HP showed alkaline pH, and the others, pH < 5.5. At-home agents could be applied for 2 h (15%, 20% CP, 6% HP) and 4 h (10% CP) and the in-office agents, up to 40 min in one application, without light.

Abstract The objective of this study was to assess the effect of a UV light-based auxiliary illumination on adhesive remnant (AR) removal after orthodontic debonding. Sixty human molars were divided according to the adhesive used for bonding: O-opaque; LF-low fluorescence; and HF-high fluorescence. After debonding, the teeth were subdivided according to the AR removal method: No UV light or With UV light. After AR removal, the teeth were polished. Direct visual analysis, scanning electron microscopy (SEM) and time quantification for AR removal analyses were performed (Fisher-Freeman-Halton, Fisher’s exact, chi-square trend, ANOVA, and independent t-tests; α = 5%). Concerning the adhesives, there was no significant difference among direct visual, SEM and time analyses for AR removal (p ≥ 0.05). Regarding AR removal methods, a similarity among the subgroups was verified for direct visual and SEM analyses (p≥0.05). However, a significant trend was verified for the with UV light method to produce greater marks, and the no UV light method, to produce a greater rate of samples with AR before polishing (p = 0.015). AR removal with light was significantly quicker in comparison with the no UV light method (p < 0.0001). The use of UV light may aid orthodontists in removing AR more thoroughly and in less time. However, they should receive special training to apply this technology, and should never dismiss the final polishing procedure.

Resumo O tratamento com cariostático tem demostrado sucesso na paralização da cárie. No entanto, causa escurecimento da estrutura dental cariada. Este estudo avaliou os efeitos de um agente cariostático experimental com nanopartículas de prata (Ag-Nano) através de microdureza (MD) e testes microbiológicos. Os cariostáticos testados foram: Saforide®, Cariestop®, Ancarie® e Ag-Nano. Sessenta e seis amostras de esmalte decíduo foram submetidos a MD inicial (após ciclagem de pH para obtenção da lesão de cárie inicial) e final (após aplicação dos cariostáticos), e os valores da porcentagem (%) de MD foram calculados. Após secção longitudinal, a MD interna (I) foi avaliada. Cepas de Streptococcus mutans, Escherichia coli e E. faecalis foram cultivados em ágar infusão de cérebro e coração (BHI) e submetidos aos cariostáticos testados. Além disso, foram realizados teste de difusão em ágar (TDA) e avaliação da concentração mínima inibitória (CIM) dos cariostáticos. Os testes estatísticos usados foram: Kruskall-Wallis e Dunn (%MD; TDA; CIM) e ANOVA seguido de teste de Tukey (MD-I) (p<0.05). A %MD do Saforide® foi significativamente maior do que a de Ag-Nano (p<0,05). A MD interna apresentou melhora progressiva na remineralização do esmalte para todos os cariostático testados. Os resultados do TDA mostraram que S. mutans, E. faecalis e E. coli sofreram maior inibição pelo Saforide® (p<0,05), em relação ao Ancarie® e Ag-Nano. No entanto, para o teste de CIM o Ag-Nano foi capaz de inibir 100% dos microorganismos, em menor concentração do que os demais cariostaticos. Conclui-se que, o tratamento Ag-Nano foi capaz de promover remineralização do esmalte dental decíduo com lesão de cárie inicial e apresentou atividade bactericida.

Abstract Cariostatic treatment has been shown to successfully arrest caries. However, it blackens the carious tooth structure. This study evaluated the effects of an experimental cariostatic agent with silver nanoparticles (Ag-Nano) using microhardness (MH) and microbiological tests. The cariostatic agents tested were: Saforide®, Cariestop®, Ancarie® and Ag-Nano. Sixty-six samples from deciduous enamel were submitted to initial (after pH cycling to obtain initial caries-like lesion) and final (after cariostatic application) MH testing and %MH values were calculated. After longitudinal sectioning, internal (I) MH was evaluated. Strains of Streptococcus mutans, Escherichia coli, and Enterococcus faecalis in brain-heart infusion culture were treated with the cariostatic agents. Agar diffusion tests (ADTs) were performed and minimum inhibitory concentrations were determined. The statistical tests used were: Kruskal-Wallis and Dunn (%MD; ADT; MIC) and ANOVA followed by Tukey’s test (I-MH) (p<0.05). The %MH of Saforide® was significantly greater than that of Ag-Nano (p<0.05). Internal MH showed progressive improvement in the enamel remineralization for all cariostatic tested. In ADTs showed greater inhibition of S. mutans, E. faecalis, and E. coli by Saforide® than by Ancarie® and Ag-Nano. Ag-Nano was able to inhibit 100% microorganism growth at a lower concentration than required for the other agents. It was concluded that Ag-Nano treatment promoted remineralization of deciduous tooth enamel with initial caries-like lesion and bactericidal activity.

Resumo O objetivo deste estudo foi avaliar a eficácia da aplicação de energia sônica sobre a resistência de união à microtração e a microdureza após o processo de restauração. Um total de 40 terceiros molares humanos foram extraídos. Cavidades Classe II foram preparadas e restauradas com os compósitos SonicFill ou Filtek Z350 XT com e sem a aplicação de energia sônica. Após os dentes serem armazenados em água durante 24 h, foram seccionados em palitos (1,0 mm2) e submetidos a ensaio de tração. Para um ensaio de dureza Knoop de profundidade, as amostras foram cortadas e as penetrações foram feitas sequencialmente a partir da superfície para o fundo das amostras em três intervalos de 1 mm cada. As amostras foram então submetidas a uma carga de 50 g durante 10 s. Os resultados dos testes de tração (fatores: sistema de inserção e compósito) e dureza (fatores: sistema de inserção x compósito x profundidade) foram submetidos ao teste de normalidade Kolmogorov-Smirnov, seguido da análise de variância e do teste de Tukey (significância de 5%). Para o fator sistema de inserção, observou-se maior resistência de união para as cavidades que foram restauradas com energia sônica (p < 0,001). Para a dureza Knoop de profundidade, a dureza a 1 mm de profundidade foi significativamente maior do que a profundidade de 3 mm apenas para as restaurações com o compósito Filtek Z350 XT sem a aplicação de energia sônica. Portanto, o uso de energia sônica durante o processo restaurador melhorou a união, mas não afetou acentuadamente a dureza de profundidade para ambos os compósitos.

Abstract The aim of this study was to evaluate the efficacy of applying sonic energy on microtensile bond strength and microhardness after the restoration process. A total of 40 human third molars were extracted. Class II cavities were prepared and restored with composite SonicFill or Filtek Z350 XT with and without the application of sonic energy. After the teeth were stored in water for 24 h, the teeth were sectioned into sticks (1.0 mm2) and subjected to tensile testing. For a depth Knoop hardness test, the samples were cut and indentations were made sequentially from the surface of the samples to the bottom of the samples in three intervals of 1 mm each. The samples were then subjected to a load of 50 g for 10 s. The results from the tensile (factors: placement system and composite) and hardness (factors: placement system, composite and depth) tests were subjected to the Kolmogorov-Smirnov normality test, followed by analysis of variance and Tukey’s test (5% significance). For the placement system factor, higher bond strength was observed for the cavities that were restored with sonic energy (p < 0.001). For depth Knoop hardness, the hardness at 1 mm depth was significantly greater than that at 3 mm depth just for the restorations with Filtek Z350 XT composite without the application of sonic energy. Therefore, the use of sonic energy during the restorative process improved bonding, yet it did not markedly affect the depth hardness for both composites.

Resumo O objetivo neste estudo foi avaliar a resistência de união ao microcisalhamento de estruturas protéticas cerâmicas reforçadas por dissilicato de lítio cimentadas com cimento resinoso sob diferentes tratamentos de superfície e sistemas adesivos. Setenta e duas barras retangulares de dissilicato de lítio (6,5 mm de comprimento × 5 mm de largura × 1 mm de espessura) foram fabricadas, tratados com partículas de Al2O3 (50 μm) e dividido em seis grupos (n=12) dependendo dos pré-tratamentos de superfície. Os grupos foram como se segue: 10HF/S/SBM: condicionamento com ácido fluorídrico 10% durante 20 s (10HF) + silano (S) + Adper Scotchbond Multi-Purpose (SBM); 10HF/S/SB: 10HF + S + Single Bond Universal (SB); 10HF/SBM; 10HF/SB; S/SBM; e S/SB. Dois tubos plásticos cilíndricos de 1 mm de comprimento foram colocados sobre os espécimes, preenchidos com cimento RelyX ARC e fotoativado durante 20 s por tubo. Os tubos plásticos foram removidos e a resistência de união ao microcisalhamento foi testada. Os dados foram submetidos à análise de variância e ao teste de Tukey (α=0,05). Espécimes fraturados foram observados sob microscopia óptica. Para ambos os adesivos, a resistência de união (MPa) dos grupos tratados com condicionamento ácido e silano (10HF/S/SB: 24,82, 10HF/S/SBM: 24,90) foram superiores (p<0.001) aos grupos tratados com condicionamento ácido apenas (10HF/SB: 16,47, 10HF/SBM: 19,94) ou apenas silano (S/SB: 18,42, S/SBM: 13,24). Todos os grupos apresentaram uma predominância de falha adesiva. A silanização deve ser um passo clínico em cimentação de estruturas cerâmicas reforçadas por dissilicato de lítio, mesmo com a aplicação do adesivo universal que contém em sua formulação um silano.

Abstract The purpose of this study was to evaluate the microshear bond strength of ceramic prosthetic structures reinforced by lithium disilicate cemented with resin cement under conditions of different surface treatments and adhesive systems. Seventy-two rectangular blocks of lithium disilicate (6.5 mm long × 5 mm wide × 1 mm thick) were fabricated, air abraded with 50-μm Al2O3 particles and divided into six groups (n=12) depending on the surface pretreatments. The groups were as follows: 10HF/S/SBM: 10% hydrofluoric acid etched for 20 s (10HF) + silane (S) + Adper Scotchbond Multi-Purpose (SBM); 10HF/S/SB: 10HF + S + Single Bond Universal (SB); 10HF/SBM; 10HF/SB; S/SBM and S/SB. Two 1-mm-long plastic tubes were placed on the specimens, filled with RelyX ARC resin cement and cured for 20 s per tube. The plastic tube was removed, and the microshear bond strength was tested. Data were submitted to analysis of variance and Tukey's tests (α=0.05). Fractured specimens were observed under optical microscopy. For both adhesives, the bond strengths (MPa) of groups treated with acid-etching and silane (10HF/S/SB: 24.82, 10HF/S/SBM: 24.90) were higher (p<0.001) than those of groups treated with acid-etching (10HF/SB: 16.47, 10HF/SBM: 19.94) only or only silane (S/SB: 18.42, S/SBM: 13.24). All groups showed a predominance of failure adhesive. The silanization should be a clinical step in cementing ceramic structures reinforced by lithium disilicate, even with the application of universal adhesive that contains silane in its formulation.

Abstract This study aimed at evaluating the Protocol for the Prevention of Malocclusions (PPM), established in the preventive educational program developed by the Public Infant Oral Health Program of the State University of Londrina (PIOHP-UEL). Guardians of three-year-olds or older, maintaining nutritive (bottle) and/or non-nutritive (pacifier and finger) sucking habits, attended meetings designed to alert and guide them to eliminating these habits from their children. PPM patient records (2006–2013) were assessed and the data were described and evaluated by the Chi-square test, with a 5% significance level. Results 506 of the 802 guardians/children referred to the PPM joined. As for the children, the most frequently assessed habits were: bottle (56.1%), bottle and pacifier (18.4%), finger (11.9%), bottle and finger (7.1%), pacifier (5.7%), pacifier and finger (0.6%), and bottle/pacifier/finger (0.2%). After parent participation in the meetings, 335 (66.2%) children abandoned their habits. There was a statistical difference between type of oral habit and time to abandonment (p = 0.0001). However, those with only one habit abandoned it more easily (72.6%) than those with two or more associated habits (48.1%) (p = 0.042). Presence or absence of breastfeeding and parents’ level of education had no significant effect on habit abandonment. Conclusion PPM was an important tool for spreading knowledge to guardians, greatly contributing to the abandonment of deleterious oral habits. Bottle sucking warrants special attention - mentioned by 81.8% of parents - either alone or associated with other habits. Thus, educational actions to implement the children’s approach to oral health are fundamental to making behavioral changes and promoting education of healthy habits, thereby keeping malocclusions from developing.

Pinos endodônticos são necessários para promover retenção e suporte adequados quando a estrutura dental remanescente não é suficiente para reter o núcleo. Há diferentes materiais e técnicas para construir o núcleo, mas não há consenso sobre o qual promove a melhor distribuição de tensão na estrutura dental remanescente. O objetivo deste trabalho foi quantificar e avaliar a distribuição de tensões produzidas nas raízes por pinos de fibra de vidro customizados quando comparados a diferentes pinos endodônticos. Vinte e cinco raízes simuladas em resina fotoelástica foram confeccionadas e divididas em 5 grupos: CPC, núcleo metálico fundido, SP, pino rosqueável; CF, pino de fibra de carbono; GF, pino de fibra de vidro; CGF, pino de fibra de vidro customizado. Depois da cimentação dos pinos de CPC e SP com cimento de fosfato de zinco e dos pinos de CF, GF e CGF com cimento resinoso, núcleos em resina foram feitos para os grupos 2-5. Os espécimes foram avaliados com carga vertical ou oblíqua a 45o. Para analisar as franjas, a área da raiz foi dividida em 6 partes: palatina cervical, palatina média, palatina apical, vestibular cervical, vestibular média e vestibular apical. As franjas formadas foram fotografadas e quantificadas. Os dados foram gravados e submetidos à ANOVA de dois fatores e ao teste de Tukey (5%). SP (1,95±0,60) mostrou maior tensão (p<0,05) quando comparado com os demais (CPC - 0,52±0,74; CF - 0,50±0,75, GF - 0,23±0,48, CGF - 0,45±0,83). Todos os pinos mostraram maior tensão no terço apical (CPC - 1,40±0,65; SP - 2,30±0,44, CF - 1,80±0,45, GF - 1,20±0,45, CGF - 1,70±1,03) Menor tensão foi encontrado no terço cervical (CPC - 0,20±0.45; CF - 0,00±0 00, GF - 0 ,0±0,00, CGF - 0,00±0,00), exceto pelo SP (1,90±0,65), que não apresentou diferença estatística (p<0,05). Pinos customizados de fibra de vidro mostraram maior concentração de estresse na raiz quando comparados com pinos convencionais de fibra de vidro, que se mostraram com comportamento biomecânico mais favorável.

Endodontic posts are necessary to provide adequate retention and support when no sufficient remaining structure is available to retain the core. There are different materials and techniques to construct post-and-core, but there is no consensus about which one promotes better stress distribution on the remaining tooth structure. This study aimed to quantify and evaluate the distribution of stress in the root produced by customized glass fiber posts compared to different endodontic posts. Twenty-five simulated roots from photoelastic resin were made and divided into 5 groups: CPC, cast post-and-core; SP, screw post; CF, carbon fiber post; GF, glass fiber post; and CGF, customized glass fiber post. After cementing CPC and SP posts with zinc phosphate cement, and CF, GF and CGF posts with resin cement, resin cores were made for groups 2-5. Specimens were evaluated with vertical or 45° oblique loading. To analyze the fringes, the root was divided into 6 parts: palatal cervical, palatal middle, palatal apical, vestibular cervical, vestibular middle, and vestibular apical. The formed fringes were photographed and quantified. Data were recorded and subjected to two-way ANOVA and Tukey's test (5%). SP (1.95±0.60) showed higher stress (p<0.05) compared to the others (CPC-0.52±0.74; CF-0.50±0.75, GF-0.23±0.48 and CGF-0.45±0.83). All posts showed high stress in apical third (CPC-1.40±0.65; SP-2.30±0.44, CF-1.80±0.45, GF-1.20±0.45, CGF-1.70±1.03) Low stress was found in cervical third (CPC-0.20±0.45; CF-0.00±0.00, GF-0.00±0.00, CGF-0.00±0.00), except by SP (1.90±0.65), which showed statistical difference (p<0.05). Customized post showed high stress concentration at the root and conventional glass fiber posts showed more favorable biomechanical behavior.

Este estudo avaliou o efeito do tempo de aplicação do chá verde na resistência de união do esmalte após o clareamento. Amostras de esmalte foram obtidas a partir de 70 terceiros molares e aleatoriamente divididas em 7 grupos experimentais (G1-G7) e um grupo sem tratamento (G8). Os 7 grupos experimentais foram tratados como segue: G1, clareado com peróxido de carbamida a 10% (PC); G2, PC + gel de ascorbato de sódio a 10% (AS) por 15 min; G3, PC + AS por 30 min; G4, PC + AS por 60 min; G5, PC + gel de chá verde a 10% (CV) por 15 min; G6, PC + CV por 30 min; G7, PC + CV por 60 min. O PC foi aplicado na superfície do esmalte por 8 h, durante 14 dias. O AS foi aplicado nos grupos 2, 3 e 4 e o CV foi aplicado nos grupos 5, 6 e 7 de acordo com os tempos de aplicação descritos acima. Imediatamente após o tratamento, foi realizado o procedimento adesivo utilizando Adper Single Bond 2 e Filtek Z350XT. Em seguida, as amostras foram preparadas para o teste de microtração. A análise do padrão de fratura foi realizada em lupa estereoscópica. Os dados foram analisados através de ANOVA (2 fatores), testes de Tukey e Dunnett (α=5%). As médias (desvio padrão) foram: G1: 23,29 (3,20); G2: 25,18 (3,95); G3: 26,41 (5,40); G4: 30,17 (4,46); G5: 26,63 (3,43); G6: 22,02 (5,41); G7: 31,40 (3,35); G8: 31,4 (3,2). Todos os grupos apresentaram maior porcentagem de falhas adesivas. Em conclusão, os valores de resistência de união foram maiores que os dos grupos clareados somente quando os antioxidantes foram aplicados por 60 min.

This study evaluated the effect of green tea application time on the bond strength of enamel after enamel bleaching. Enamel samples were obtained from 80 third molars and randomly divided into 7 experimental groups (G1-G7) and 1 group without treatment (G8): G1, bleached with 10% carbamide peroxide (CP); G2, CP + 10% sodium ascorbate gel (SA) for 15 min; G3, CP + SA for 30 min; G4, CP + SA for 60 min; G5, CP + 10% green tea gel (GT) for 15 min; G6, CP + GT for 30 min; G7, CP + GT for 60 min. The CP was applied onto the enamel surface for 8 h for 14 days. The SA was applied in groups 2, 3 and 4, and the GT was applied in groups 5-8 according to the above described application times. Immediately after treatment, the specimens were bonded with Adper Single Bond 2 and Filtek Z350XT. The specimens were prepared to microtensile bond strength analysis. Fracture mode analysis was performed using a stereoscopic loupe. The data were statistically analyzed by two-way analysis of variance, the Tukey's and Dunnett's tests (=5%). The means (standard deviation) were: G1, 23.3 (3.2); G2, 25.2 (3.9); G3, 26.4 (5.4); G4, 30.2 (4.5); G5, 26.6 (3.4); G6, 22.0 (5.4); G7, 31.4 (3.3); G8, 31.4 (3.2). All groups had a high percentage of adhesive failures. In conclusion, the bond strength values were higher than the value in the bleached group only when the antioxidants were applied for 60 min.

AIM: To evaluate the effects of three hydrogen peroxide (HP) concentrations on enamel mineral content (MC), following three peroxide applications and using three methods to measure the MC. METHODS : Forty samples were obtained from bovine incisors and randomly divided into 4 groups (n=10). The control group remained untreated, while the experimental groups were tested for three HP concentrations (10%, 35% and 50%). The HP gel was applied 3 times on the enamel surface for 30 min per application and the samples were analyzed after each application. The MC of the enamel was determined before and after bleaching using Fourier transform (FT-Raman) spectroscopy and micro energy-dispersive x-ray fluorescence spectrometry (µEDXRF). The calcium (Ca) lost from the bleached enamel was quantified with an atomic absorption spectrometer (AAS). The data were analyzed statistically by ANOVA, Tukey and Dunnett´s tests (p<0.05). RESULTS: The FT-Raman showed a decrease in MC for all bleaching treatments, without influence of the different HP concentrations or the number of applications. µEDXRF did not detect any changes in MC. CONCLUSIONS: Ca loss was observed by the AAS, with no difference among the three HP concentrations. The FT-Raman and AAS analyses detected MC reduction and Ca loss after HP bleaching.

Este estudo avaliou a variação de temperatura na câmara pulpar durante a fotoativação de duas resinas compostas (Filtek P90 – compósito à base de silorano e Heliomolar – compósito à base de metacrilato) com as unidades foto-ativadoras (UFs) luz de quartzo-tungstênio-halogênio (QTH) ou diodo emissor de luz (LED) e utilizando espessuras de dentina (0,5 e 1,0 mm). Cavidades padronizadas (2×2×2 mm) foram preparadas em 80 incisivos bovinos, as quais foram aleatoriamente divididas em 8 grupos de acordo com os métodos de fotoativação e espessura da dentina. Filtek P90 e Heliomolar (ambos na cor A3) foram utilizadas com seus respectivos sistemas adesivos (Primer P90 auto-condicionante / adesivo P90 e adesivo Excite). Todos os experimentos foram realizados em um ambiente controlado (37°C). As variações de temperatura (°C) foram mensuradas usando um termômetro digital conectado a um termopar tipo-K. Os resultados foram analisados estatisticamente por ANOVA e teste de Tukey (α=0,05). Para interação compósito/espessura de dentina, o aumento da temperatura foi estatisticamente superior para a espessura de dentina de 0,5 mm (40,07°C) quando comparado com a espessura de dentina de 1,0 mm (39,61°C) para a Filtek P90. Para a interação compósito/UFs, o aumento de temperatura foi estatisticamente superior para o Filtek P90 (39,21°C – QTH e 40,47°C – LED) quando comparado ao Heliomolar (38,40°C – QTH e 39,30°C – LED). Compósitos à base de silorano promovem maior aumento da temperatura na câmara pulpar em relação aos compósitos à base de metacrilato.

This study evaluated the temperature variation in the pulp chamber during photoactivation of two restorative composite resins (Filtek P90 silorane-based composite and Heliomolar methacrylate-based composite) with either a quartz-tungsten-halogen (QTH) or light-emitting diodes (LED) light-curing unit (LCU) and using dentin thicknesses (0.5 and 1.0 mm). Standardized cavities (2x2x2 mm) were prepared in 80 bovine incisors, which were randomly assigned to 8 groups according to the photoactivation method and dentin thickness. Filtek P90 and Heliomolar (both in shade A3) were used with their respective adhesive systems (P90 self-etch primer / P90 adhesive bond and Excite adhesive). All experiments were carried out in a controlled environment (37°C). The temperature variations (°C) were recorded using a digital thermometer attached to a K-type thermocouple. The results were analyzed statistically by ANOVA and Tukey's test (α=0.05). For composite/dentin thickness interaction, temperature increase was significantly higher in 0.5 mm dentin thickness (40.07°C) compared with 1.0 mm dentin thickness (39.61°C) for Filtek P90. For composite/LCU interaction, the temperature increase was significantly higher for Filtek P90 (39.21°C - QTH and 40.47°C - LED) compared with Heliomolar (38.40°C - QTH and 39.30°C - LED). The silorane-based composite promoted higher temperature increase in the pulp chamber than the methacrylate-based composite.