Análise comparativa dos cimentos MTA cinza e branco associados ao álcool isopropílico

• Autor(a) principal: Maciel, Ana Carolina de Carvalho
• Data de Publicação: 2016
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/14046
• topic: Endodontics; Microbiology; Isopropanol; Biocompatibility; Cell culture; Cytotoxicity; Endodontia; Microbiologia; Isopropanol; Biocompatibilidade; Cultura de célula; Citotoxicidade; CNPQ::CIENCIAS DA SAUDE::ODONTOLOGIA::ENDODONTIA

The aim of this study was to investigate and compare the antibacterial effects, cytotoxicity, marginal adaptation and sealing ability of mineral trioxide aggregate (MTA), white and gray (Angelus, Londrina, Brasil), when combined with distilled water or isopropyl alcohol. The antibacterial effects of both formulations were evaluated by agar diffusion method using Staphylococcus aureus (ATCC25923) and Pseudomonas aeruginosa (ATCC27853) for selecting the suitable concentration of isopropyl alcohol. The antimicrobial mechanism by the generation of reactive oxygen species (ROS) was first analyzed using Escherichia coli strains: proficient (AB1157) and triple mutant (BW535), deficient in the repair mechanisms. The ROS generation was also analyzed by degradation of DNA plasmid (electrophoresis method) and with the DCF probe. The generation of reactive nitrogen species (RNS) was assessed by DAF probe. The cytotoxicity of the eluates was assessed by MTT test, with L929 cells. The marginal adaptation was evaluated by scanning electron microscopy (SEM). The sealing ability was performed using bacterial leakage assay. The results showed that the incorporation of isopropanol to MTA increased the inhibitory haloes in Gram-positive model (S. aureus-ATCC25923) (P <0.05). Adding 70% isopropanol to white and gray MTA cements increased antimicrobial activity against both E. coli wild (AB1157) and triple-mutant (BW535) strains (P <0.0001). The DNA plasmid was not completely degraded for the samples of white and gray MTA manipulated with 70% isopropanol. The white and gray MTA samples, handled according to the manufacturer, generated significantly more ROS (DCF probe) (P <0.0001 e P =0.0002) and RNS (DAF probe) (P =0.0002 e P =0.0003) than that manipulated with 70% isopropanol. The cements handled with distilled water were more cytotoxic than when associated with isopropanol solution 70% (P <0.05). The SEM analysis showed better adaptation to the cavity prepares when the samples were filled with MTA with 70% isopropanol, however the ex vivo bacterial infiltration test with Enterococcus faecalis (ATCC29212), was not statistically different from samples manipulated with isopropanol or water (P >0.05). We can conclude that the manipulation with isopropanol improved the antimicrobial activity of the MTA rendering less citotoxicity, without altering the sealing ability.