Evaluation of ceramic veneer adaptation by optical coherence tomography: a clinical report / Avaliação da adaptação de laminado cerâmico por tomografia de coerência óptica: relato de caso

Introduction: Ceramic veneers represent a treatment approach in aesthetic dentistry. They are indicated in cases of alterations in size, contour, form and color of the teeth. The clinical and radiographic examinations may not allow the correct identification of failures in the treatment with ceramic veneers. Objective: To report the use of Optical Coherence Tomography (OCT) for the evaluation and repair of an aesthetic oral rehabilitation involving ceramic veneers. Case report: A 24-year-old female patient complained of unsatisfied color change in the ceramic veneer placed on the right maxillary central incisor. The clinical examination showed color changes between the middle and incisal thirds of mesial surface of the tooth crown. The OCT sagittal images evidenced the presence of bubbles or gaps in the adhesive interface. The treatment consisted of repair of the restoration by infiltration of a composite resin. Conclusion: The OCT was found to be valid tool to evaluate the adaptation of the ceramic veneer placed on the maxillary central incisor (AU)

Introdução: Laminados cerâmicos representam uma abordagem de tratamento em Odontologia. São indicados em casos de alterações no tamanho, contorno, forma e cor dos dentes. O exame clínico e o emprego de radiografias convencionais podem não permitir a correta identificação de falhas no tratamento com laminados cerâmicos. Objetivo:Relatamos o uso da tomografia de coerência óptica (TCO) para avaliação da adaptação e reparo de uma reabilitação oral estética com laminados cerâmicos. Relato de caso:Paciente do sexo feminino, 24 anos, queixou-se de alteração de cor em laminado cerâmica cimentado no incisivo central superior direito. O exame clínico evidenciou alterações de cor entre os terços médio e incisal da superfície mesial do dente. As imagens obtidas por TCO mostraram a presença de bolhas ou gaps na interface adesiva da região. O plano de tratamento consistiu no reparo mediante infiltração de uma resina composta no local indicado pela TCO. Conclusão: A tomografia de coerência óptica se mostrou um método auxiliar eficaz para análise da adaptação do laminado cerâmico no incisivo superior direito. (AU)

Initial and pulp chamber concentration of hydrogen peroxide using different bleaching products / Concentração de peróxido de hidrogênio na câmara pulpar utilizando diferentes produtos clareadores

Objective: This study's aim was to quantify the hydrogen peroxide (HP) penetration into the pulp chamber of teeth submitted to different protocols of bleaching. Material and Methods: Ninety premolars were randomly divided into nine groups according to the bleaching agent protocol (n = 10): control (no bleaching), carbamide peroxide 10% [10% CP], carbamide peroxide 16% [16% CP], carbamide peroxide 22% [22% CP], hydrogen peroxide 4% [4% HP], hydrogen peroxide 6% [6% HP], hydrogen peroxide 7.5% [7.5% HP], hydrogen peroxide 10% [10% HP] and hydrogen peroxide 35% [35% HP]. The penetration of HP was measured via spectrophotometric analysis of the acetate buffer solution from the pulp chamber. The absorbance of the resulting solution was determined in a spectrophotometer and converted into equivalent concentration of HP (µg/ mL). To analyze the concentration of HP, the titration of bleaching agents with potassium permanganate was used. Data were subjected to ANOVA and Tukey's test for pairwise comparison (α = 0.05). Results: Higher concentration of HP in the pulp chamber was found in the HP 35% group (p < 0.0001). No significant difference between at-home protocols were observed (p = 0.64). Titration values showed that the concentration of the products was similar to that claimed by the manufacturer. Conclusion: It follows that the amount of HP that reaches the pulp chamber is not proportional to the concentration of whitening gels, but depends on the application time recommended by the manufacturers (AU)

Objetivo: o objetivo deste estudo foi quantificar a penetração do peróxido de hidrogênio (PH) na câmara pulpar dos dentes submetidos a diferentes protocolos de clareamento. Material e Métodos: Noventa pré-molares foram divididos aleatoriamente em nove grupos, de acordo com o protocolo do agente clareador (n = 10): controle (sem clareamento), peróxido de carbamida 10% [PC 10%], peróxido de carbamida 16% [PC 16%], peróxido de carbamida 22% [PC 22%], peróxido de hidrogênio 4% [PH 4%], peróxido de hidrogênio 6% [PH 6%], peróxido de hidrogênio 7,5% [PH 7,5%], peróxido de hidrogênio 10% [PH 10%] e peróxido de hidrogênio 35% [PH 35%]. A penetração de PH foi medida por análise espectrofotométrica da solução de tampão de acetato da câmara pulpar. A absorvância da solução resultante foi determinada em um espectrofotômetro e convertida em concentração equivalente de PH (µg / mL). Para analisar a concentração de PH, foi utilizada a titulação de agentes clareadores com permanganato de potássio. Os dados foram submetidos à ANOVA e teste de Tukey para comparação pareada (α = 0,05). Resultados: Foi encontrada maior concentração de PH na câmara pulpar no grupo PH 35% (p < 0,0001). Não foi observada diferença significativa entre os protocolos domiciliares (p = 0,64). Os valores de titulação mostraram que a concentração dos produtos era semelhante à reivindicada pelo fabricante. Conclusão: Conclui-se que a quantidade de PH que atinge a câmara pulpar não é proporcional à concentração de géis clareadores, porém depende do tempo de aplicação recomendado pelos fabricantes.(AU)

Fracture resistance of extensive bulk-fill composite restorations after selective caries removal

Abstract This study evaluated the effect of selective carious tissue removal on the fracture strength and failure mode of composite restorations in molars presenting only the buccal cusps. Deep cavities were prepared on the occlusal surface, and the lingual cusps were removed. Carious lesions in the middle of the pulpal wall were artificially induced with acetic acid (pH = 4.5) for 35 days. The demineralized dentin was left intact or was completely removed prior to restoration with a bulk-fill composite (n = 10). Images of the specimens were obtained by optical coherence tomography (OCT) before and after the caries induction/removal. The mechanical resistance to fracture by axial compressive loading and the failure type and extension were determined. The pulpal wall/composite interface of the fractured specimens was analyzed by OCT. The data were analyzed for significance with t-tests (α = 0.05). The deepest cavities and a more frequent occurrence of pulpal exposure were observed more often for non-selective carious tissue removal. The protocol of carious tissue removal did not affect the fracture strength (p = 0.554). An increased occurrence of catastrophic failures involving the roots was observed for non-selective carious tissue removal. Some occurrences of restoration displacement or cracks throughout the resin-dentin were observed only for the selective carious tissue approach. Selective carious tissue removal is a feasible approach to extensively damaged teeth since it reduced the occurrence of pulpal exposure and root fractures, without compromising the fracture strength.

Remineralizing Potential of Nano-Silver-Fluoride for Tooth Enamel: An Optical Coherence Tomography Analysis

Objective: To evaluate the use of nanosilver fluoride in the enamel remineralization process through optical coherence tomography. Material and Methods: All samples were submitted to demineralization process by pH cycling during 14 days and randomly distributed into three groups (n = 11): Nanosilver Fluoride (NSF), Sodium fluoride (NaF), and negative control. Optical coherence tomography images were acquired at three different moments: initial stage (T0), post caries formation (T1), and post pH cycling (T2). The integrity of the enamel surface and the measurement of the volume loss for the tissue after pH cycling in comparison to initial images were obtained from optical coherence tomography images. Results: After analyzing the exponential decay of A-scans from each group, it was possible to identify differences in light propagation among samples. In T1 it is not possible to visualize the dentin-enamel junction, probably due to the higher back scattering of the demineralized enamel, which does not allow light to reach the dentin. The decay curves obtained from NaF and nanosilver fluoride groups showed similar behavior, while the negative group showed lower extinction coefficient. Conclusion: Nanosilver fluoride showed the best effect against caries compared to conventional fluoride treatments.

Terrible triad of the elbow: influence of radial head treatment / Tríade terrível do cotovelo: a influência do tratamento da cabeça do rádio

Objective: To test the null hypothesis that patients with the terrible triad of the elbow (dislocation together with fractures of the radial head and coronoid process) who are treated with open reduction and internal fixation of the radial head have final results that are comparable with those of patients treated with arthroplasty or partial resection of the radial head. Methods: Twenty-six patients with the terrible triad of the elbow who were operated by a single surgeon were evaluated on average 23 months after the surgery (range: 16–36 months). There were 17 men and nine women of mean age 41 ± 13.4 years. The fractures of the radial head were treated by means of osteosynthesis (12 patients), arthroplasty (nine) or resection of a small fragment or no treatment (five). Fixation of the coronoid process/anterior capsule was performed in 21 patients. The lateral ligament complex (LLC) was repaired in all the patients, while the medial ligament complex (MLC) was repaired in three patients whose elbows remained unstable after treatment for the radial head and LLC, but without fixation of the coronoid process. Results: The mean final range of flexion and extension was 112°. The mean pronation was 70° and supination, 6°. The mean DASH score (Disabilities of the Arm, Shoulder & Hand) was 12 and mean MEPI (Mayo Elbow Performance Index) was 87. According to the MEPI scores, 21 patients (80%) had good and excellent results. There was no statistically significant difference in the results between the patients who underwent fixation of the radial head and those who underwent arthroplasty or resection of a small fragment. Conclusion: There was no difference between the patients treated with arthroplasty of the radial head and those treated with other techniques. .

Objetivo: Testar a hipótese nula de que os pacientes com a tríade terrível do cotovelo (luxação associada a fraturas da cabeça do rádio e do processo coronoide) tratados com redução aberta e fixação interna da cabeça do rádio têm resultado final comparável aos pacientes tratados com artroplastia ou ressecção parcial da cabeça do rádio. Métodos: Foram avaliados, em média aos 23 meses (16 a 36) após a cirurgia, 26 pacientes com a tríade terrível do cotovelo operados por um único cirurgião. Eram 17 homens e nove mulheres, com média de idade de 41 anos (± 13,4). As fraturas da cabeça do rádio foram tratadas com osteossíntese (12 pacientes), ou artroplastia (nove), ou ressecção de um fragmento pequeno ou nenhum tratamento (cinco). Fixação do processo coronoide/cápsula anterior foi feita em 21 pacientes. O complexo ligamentar lateral (LCL) foi reparado em todos os pacientes, enquanto que o complexo ligamentar medial (LCM) foi reparado em três pacientes cujos cotovelos persistiam instáveis após o tratamento da cabeça do rádio e do LCL, mas sem fixação do processo coronoide. Resultados: O arco final médio de flexão e extensão foi de 112°. A pronação média foi de 70° e a supinação, de 6°. O escore Dash (Disabilities of Arm, Shoulder & Hand) médio foi de 12 e o Mepi (Mayo Elbow Performance Index) médio foi de 87. De acordo com o Mepi, 21 pacientes (80%) tiveram bons e excelentes resultados. Não houve diferença estatisticamente significativa entre os resultados dos pacientes submetidos a fixação da cabeça do rádio e aqueles submetidos a artroplastia ou ressecção de um fragmento pequeno. Conclusão: Não há diferença ...

Ansiedade e desempenho: um estudo com uma equipe infantil de voleibol feminino / Anxiety and performance: a study of an infant female volleyball team

O objetivo deste estudo foi analisar a "ansiedade traço‟ e "ansiedade estado‟ e sua relação com o desempenho pré-competitivo e competitivo no voleibol. O caso estudado foi uma equipe de voleibol feminina infantil. Utilizou-se como instrumentos de medida os protocolos CSAI–II e o SCAT. A coleta de dados ocorreu nos locais de treinamento e durante os Jogos Colegiais 2005. Para a análise dos dados utilizou-se estatística descritiva e o teste “t” de Student. Os resultados indicaram: "ansiedade traço‟ pré-competitiva e competitiva sem diferenças significativas, porém na "ansiedade estado‟ observou-se diferença significativa (P=0,05) para o componente cognitivo. Verificou-se um equilíbrio entre os componentes da "ansiedade estado‟ na fase preparatória pelas vitórias em todos os jogos, o que se mostrou diferente na fase competitiva, onde a equipe sofreu duas derrotas. Conclui-se que a ansiedade pode afetar o desempenho das atletas na situação competitiva nesta modalidade e categoria estudada.

The objective of this study was to analyze trait anxiety and state anxiety and their relation with pre-competitive and competitive performance in volleyball. The case studied was a infantile female volleyball team. The measure instruments used were the CSAI-II and SCAT protocols. Data collection occurred in training stations and during High School games 2005. Data analysis was performed through descriptive statistics and Student's “t” test. The results indicated: pre-competitive and competitive trait anxiety with no significant differences, however in relation to state anxiety a significant difference was observed (P=0,05) in the cognitive component. A balance was verified between state anxiety components in preparation phase because of the winnings in all games, fact that was different in the competitive phase, where the team lost two times. It is concluded that anxiety can affect athletes' performance in competitive situation in the modality and category studied.

Fracture process characterization of fiber-reinforced dental composites evaluated by optical coherence tomography, SEM and optical microscopy

This study used optical coherence tomography (OCT) compared to scanning electron microscopy (SEM) and optical microscopy (OM) to evaluate qualitatively crack propagation and final fracture in restorative composite materials - Filtek Z250 and Filtek Z350 (3M ESPE) - with fiber reinforcement after cyclic loading. Samples were made using a split mold. Initially, 3-point bending tests were performed to determine the maximum force and tension at the fracture moment using samples without fiber reinforcement. Then, mechanical cycling tests were performed using samples with glass fiber embedded internally. The failures were analyzed using the 3 methods described before. OCT permitted good characterization of internal crack propagation of the dental composites, which, however, could not be visualized by either SEM or OM. OCT was proven to be laboratory research tool that is easy to use, does not require any specific preparation of the samples, and is less expensive than SEM.

Perspectives on in vitro fungal diagnosis with UV light

O aumento na incidência de infecções fúngicas e a crescente habilidade dos organismos em adquirirem resistência a tratamentos antimicrobiais tornam necessária a introdução de métodos de identificação rápida de fungos e bactérias. Em dermatologia, técnicas ópticas que exploram luz ultravioleta, como o método de Wood, apresentam-se como importantes ferramentas para o diagnóstico clínico de infecções dermatológicas. Neste trabalho são exploradas técnicas de espectroscopia óptica por fluorescência na identificação de fungos. O método aplicado utiliza diferentes fontes de luz ultravioleta (lâmpada, LED, Laser) para excitar opticamente cromóforos de alguns de fungos (in vitro). Seis espécies de fungos (Microsporum gypseum, Microsporum canis, Trichophyton schoenleinii, Trichophyton rubrum, Epidermophyton floccosum e Fusarium solani) foram investigadas. Os resultados obtidos demonstram que algumas das limitações no diagnóstico de fungos com lâmpada de Wood podem ser superadas utilizando análises espectroscópicas refinadas. A largura espectral e o comprimento de onda de pico da fluorescência emitida pelos fungos são parâmetros que podem ser usados na distinção de microorganismos de espécies diferentes. Foi verificado também que, com a excitação óptica de fungos por LEDs, a luz emitida pelos microorganismos apresenta as mesmas características espectrais da fluorescência obtida com a excitação por uma lâmpada de Wood. Os resultados aqui apresentados indicam a possibilidade do uso de LEDs e LASERs no diagnóstico clínico de infecções fúngicas.