RESUMO
Resin-based restorative materials, widely used to cement posts, may be influenced by irrigants used during endodontic chemical-mechanical preparation. This study evaluated the impact of endodontic irrigating solutions and adhesive cement systems on the push-out shear bond strength of glass fiber posts to root dentin. Ninety-six bovine incisors were divided into 12 groups (4 irrigants × 3 resin cements; n = 8). Prepared canals were irrigated with saline solution, 2.5% sodium hypochlorite (NaOCl), 5.25% NaOCl, or 2% chlorhexidine gel, and posts were cemented with RelyX ARC, Panavia F, or RelyX U100. The bond strength was evaluated by means of the push-out test, and results were subjected to analysis of variance. The mean bond strength observed for the combination of 5.25% NaOCl irrigant and RelyX U100 cement was significantly lower (8.82 MPa) than the values found for the other groups (P < 0.05). The other combinations of irrigating solution and resin cement had no adverse effect on the bond strength of the glass fiber posts to dentin.
Assuntos
Técnica para Retentor Intrarradicular , Cimentos de Resina/uso terapêutico , Irrigantes do Canal Radicular/uso terapêutico , Preparo de Canal Radicular/métodos , Animais , Bovinos , Colagem Dentária/métodos , Resistência ao CisalhamentoRESUMO
O mecanismo de ação dos agentes clareadores consiste de uma reação química de oxirredução, que pode ser acelerada por uma fonte de luz ou calor. Apesar do aumento de temperatura favorecer uma reação mais rápida este deve ser limitado, a fim de se evitar danos pulpares irreversíveis. Fontes de energia como laseres e LEDs estão sendo bastante utilizadas objetivando um clareamento seguro e efetivo, desde que utilizados com moderação. A associação dessas duas fontes levou ao desenvolvimento de aparelhos que apresentam duas unidades geradoras de luz, um sistema de luz fria emitida por LEDs e um sistema de luz laser de diodo. Este trabalho relata um caso clínico de clareamento de consultório que teve sua ação potencializada por LEDs associados ou não ao laser de diodo. Ambos os sistemas foram efetivos na ativação do agente clareador. Porém, a mudança de cor do gel clareador ocorreu mais rápida quando a associação LED/laser de diodo foi utilizada.
The action mechanism of bleaching agents consists of a chemical oxireduction reaction, which can be accelerated by a light or heat sources. Although the temperature increase contributes to a faster reaction, this should be limited in order to avoid irreversible pulp damages. Sources of energy like laser and LED's have been used aiming an effective and safe bleaching treatment, once their use is moderated. The association between these two sources provided the development of specific devices with two light unit generators, a system of cold light emitted by LED's and a diode laser system. This work reports an in-office bleaching clinical case which had the action potentiated by the use of LED's associated or not to a diode laser. Both systems were effective in the bleaching agent activation. However, the color change of the whitening gel ocurred faster when LED/diode laser association was used.
