Análise da resistência de união adesiva de retentores intrarradiculares metálicos e estéticos cimentados em condutos irradiados com laser de diodo de alta potência (830nm)

Abstract

Após a irradiação os retentores foram cimentados com cimento de fosfato de zinco ou com cimento resinoso autocondicionante. As raízes foram seccionadas por meio de cortes transversais dos terços cervical, médio e apical, obtendo-se, assim, seis amostras de cada raiz. Cada uma das amostras foi submetida ao ensaio de resistência de união de maneira cega. Conclui-se que a resistência mecânica à compressão de retentores intrarradiculares em dentina previamente irradiada com laser de diodo de alta intensidade (λ= 830 nm) apresentou maiores valores na dentina intrarradicular tanto no regime contínuo como pulsado, sendo ligeiramente superior no regime pulsado. Foi 8 possível verificar que, nos terços médio e cervical, a irradiação com laser de diodo pulsado (P m = 1 W, I = 994 W/cm 2 ) resultou em maiores valores de resistência de união, com ambos os cimentos e ambos os tipos de núcleo.Houve diferença estatisticamente significante nos valores de união nos diferentes terços dos grupos tratados, sendo superior para o terço cervical (p < 0,05). Assim, a técnica de irradiação do conduto com laser de diodo mostrou-se eficaz no aumento da resistência de união de retentores intrarradiculares. 9 ANALYSIS OF BOND STRENGTH IN ESTECTICS AND METAL POSTS CEMENTED IN ROOT CANALS IRRADIATED WITH HIGH POWER DIODE LASER (830 nm)CLÁUDIA STREFEZZA AbstractThe aim of this study was to evaluate, in vitro, the bond strength of intracanal post cemented on irradiated dentin by a high intensity diode laser (λ = 830 nm), both continuous and pulsed regime. Metal or fiber glass posts were used and cemented with zinc phosphate cement or self-etching resin-based cement. Thus, the variables analyzed were the regime of irradiation, the type of post and type of luting agent on bond strength. These variables were analyzed in vitro the 3 root thirds (cervical, middle and apical) of 90 endodontically treated human teeth prepared to receive posts and irradiated with diode laser at high intensity (830 nm). After irradiation, posts were cemented with zinc phosphate or self-etching resin cement. The roots were transversely in the cervical, middle and apical thirds, resulting in six samples each root. Each sample was subjected to the test of bond strength blindly. We concluded that the mechanical strength of intracanal posts cemented on dentin irradiated by high intensity diode laser (λ = 830 nm)showed higher adhesion values in dentin, both for continuous and pulsed regime, being slightly higher in the pulsed regime. It was possible to verify that in the cervical and middle thirds, irradiation with pulsed diode laser (Pm = 1 W, I = 994 W/cm 2 ) resulted in higher bond strength using both cements and both types posts. There was a significant difference among the different thirds of the treated groups, being higher for the cervical third (p < 0,05). So, irradiation with diode laser was effective to increase the resistence of union of intrarradicular posts. 10