Estudo da permeabilidade dentinária a diferentes fotossensibilizadores empregados na terapia fotodinâmica

• Ano de defesa: 2011
• Autor(a) principal: Graciano, Ariane Ximenes
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual de Maringá; Brasil; Departamento de Odontologia; Programa de Pós-Graduação em Odontologia Integrada; UEM; Maringá, PR; Centro de Ciências da Saúde
• Palavras-chave em Português: Terapia fotodinâmica; Permeabilidade dentária; Cárie dentária; Fotossensibilizadores; Brasil.; Photodynamic therapy; Dentin permeability; Dental cavity; Dental permeability; Photosensitizers; Brazil.; Ciências da Saúde; Odontologia
• Link de acesso: http://repositorio.uem.br:8080/jspui/handle/1/2112

The photodynamic therapy (PDT) has been presented as a conservative alternative and promising for the decontamination of carious dentin acts as an adjuvant in the treatment of dental caries through its inactivation of microorganisms. The antimicrobial effect of PDT is the result of photochemical reactions that occur with the association of a photosensitizer (PS) and a light source applied at the affected site. The dentin permeability to PS used in PDT is an important factor for its occurrence since, if there is a minimal permeation of PS in the dentin, the effect of PDT is superficial. Meantime, if there is a high PS permeation, adverse effects may occur that are not yet known. Then, the aims of this study was evaluate in vitro using the photoacustic spectroscopy (PAS) the dentin permeability of different PS used in PDT, evaluate the effect of different concentration and exposure time of PS on dentin permeability, and evaluate in vitro using the photoacustic Fourier transform infrared spectroscopy (PA-FTIRS) to investigate chemical modifications between PS and dentin. So the PS Methylene Blue (MB), Toluidine Blue O (TBO) and Malachite Green (MG) with 0,1 mg/mL and 0,01 mg/mL concentration was applied in 24 dentin human samples, during 1, 5 or 30 minutes, and they were submitted to PAS to quantify the permeability. In PA-FTIRS, 3 dentin samples were used, one sample for each PS with 0,1 mg/mL. To investigate the PS impregnation in dentinal tubules 3 dentin samples were evaluates in optical microscopy and 6 dentin samples were used to evaluate the dentinal tubules characteristics in scanning electron microscopy. According to results the three PS permeated in dentin, the MB 0,1 mg/mL exposed during 5 minutes presented the highest average (0,246 mm) while the MG 0,1 mg/mL exposed during 5 minutes presented the lowest average (0,180 mm). The exposure time of 5 minutes (0,246 mm) or 30 minutes (0,245 mm) didn't influence in MB permeation behavior, on the other hand the TBO and MG varied on permeation behavior for periods of 5 minutes (0,220 mm and 0,180 mm), and 30 minutes (0,193 mm and 0,237 mm), respectively. For the period of 1 minute the three PS had similar permeation (0,150 mm). There weren?t chemical bonds between the PS and dentin, and occurred PS impregnation in dentinal tubules. Thus concludes that the PS evaluates have favorable capacity of permeation on dentin structure which enables their use in PDT for the decontamination of carious dentin as an adjunct in the treatment of dental caries.