ABSTRACT
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)
Subject(s)
Humans , Female , Adult , Dental Veneers , Tomography, Optical Coherence , Esthetics, DentalABSTRACT
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.
Subject(s)
Humans , Fractures, Bone , Composite Resins , Dental Caries , Dental Restoration, Permanent , MolarABSTRACT
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.
Subject(s)
Tooth Demineralization/diagnosis , Nanotechnology/methods , Dental Enamel , Tomography, Optical Coherence/methods , Fluorides , In Vitro Techniques/methods , BrazilABSTRACT
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.