ABSTRACT
O objetivo desse estudo foi avaliar a radiodensidade de 7 cimentos resinosos: Panavia F (PA- Kuraray Medical), Enforce (En- Dentsply Latin America), Ecolink (Ek-Ivoclar Vivadent), Rely X ARC (Re-3M ESPE), Rely X Unicem (Un-3M ESPE), Multlink (Mk-Ivoclar Vivadent) e Variolink II (Vk-Ivoclar Vivadent). Os cimentos foram manipulados de acordo com as instruções dos fabricantes e inseridos em uma matriz acrílica de 1 × 1 × 10 mm3 (n = 8) e foto ativados por 40 segundos com luz halógena (750 mW.cm elevado a -2, Optilux 501). Após 24 horas de armazenamento no escuro em umidade relativa à 37 °C por 24 horas, os espécimes foram posicionados sobre filmes radiográficos juntamente com uma escala de alumínio. Os filmes foram expostos ao raio X com 60 kV, 10 mA, com a distância foco filme de 10 cm por 0,7 segundos. Os filmes foram revelados e a radiodensidade dos espécimes foi avaliada qualitativamente por ranqueamento utilizando-se os degraus da escala de alumínio, atribuindo do escore 1 para o mais radiolucente ao escore 10 para o mais radiopaco. Os dados foram analisados pelo teste de Kruskal-Wallis e de Dunn (p < 0,05). A mediana obtida para cada cimento foi: Pa= 2ª, En= 3ª; Ec= 3ª; Re= 3,5ª, Un= 4ab; Mk= 7b; Vk = 8b (medianas seguidas por diferentes letras indicam diferença estatística significante). Pôde-se concluir que os cimentos resinosos apresentam diferentes níveis de radiodensidade. O Panavia F, Enforce, Ecolink, and Rely X ARC foram os mais radiolucentes, o Unicem apresentou radiodensidade intermediária, e o Multilink e o Variolink II foram os cimentos que apresentaram maior radiopacidade.
The aim of this study was to evaluate the radiodensity of 7 resin cements: Panavia F (PA- Kuraray Medical), Enforce (En-Dentsply Latin America), Ecolink (Ek-Ivoclar Vivadent), Rely X ARC (Re- 3M ESPE), Rely X Unicem (Un?3M ESPE), Multlink (Mk- Ivoclar Vivadent) and Variolink II (Vk- Ivoclar Vivadent). The cements were mixed according to manufacturer's instructions and inserted into 1 × 1 × 10 mm3 (n = 8) acrylic molds and photo-activated for 40 seconds with halogen light (750 mW.cm to the -2 power, Optilux 501). After 24 hours of storage in relative humidity at 37 °C in a dark box for 24 hours, the specimens were positioned on the X ray films with an aluminum scale. The film was exposed to 60 kV and 10 mA X ray, with a focus-film distance of 10 cm for 0.7 seconds. The films were revealed and the radiodensity of the specimens was evaluated qualitatively by ranking according to the scale steps, with rank 1 for the most radiolucent to rank 10 for the most radiopaque. The data were submitted to Kruskal-Wallis and Dunntests (p < 0.05). The median obtained for each cement was: Pa= 2ª, En= 3ª; Ec= 3ª; Re= 3.5ª, Un= 4ab; Mk= 7b; Vk= 8b (medians followed by different letters differ among them). It can be concluded that resin cements showed different degrees of radiodensity. Panavia F, Enforce, Ecolink, and Rely X ARC were the most radiolucent, Unicem presented intermediary radiodensity, and Multilink and Variolink II were the most radiopaque cements.
Subject(s)
X-Rays , Radiography, Dental , Statistics, Nonparametric , Resin Cements , Dental CementsABSTRACT
This study evaluated the degree of conversion (DC) and ultimate tensile strength (UTS) of dual-cured resin cements heated to 50º C prior to and during polymerization. Disc- and hourglass-shaped specimens of Rely X ARC (RX) and Variolink II (VII) were obtained using addition silicon molds. The products were manipulated at 25º C or 50º C and were subjected to 3 curing conditions: light-activation through a glass slide or through a pre-cured 2-mm thick resin composite disc, or they were allowed to self-cure (SC). All specimens were dark-stored dry for 15 days. For DC analysis, the resin cements were placed into the mold located on the center of a horizontal diamond on the attenuated total reflectance element in the optical bench of a Fourier Transformed Infrared spectrometer. Infrared spectra (n = 6) were collected between 1680 and 1500 cm-1, and DC was calculated by standard methods using changes in ratios of aliphatic-to-aromatic C=C absorption peaks from uncured and cured states. For UTS test, specimens (n = 10) were tested in tension in a universal testing machine (crosshead speed of 1 mm/min) until failure. DC and UTS data were submitted to 2-way ANOVA, followed by Tukey's test (α= 5 percent). Both products showed higher DC at 50º C than at 25º C in all curing conditions. No significant difference in UTS was noted between most light-activated groups at 25º C and those at 50º C. VII SC groups showed higher UTS at 50º C than at 25º C (p < 0.05). Increased temperature led to higher DC, but its effects on resin cement UTS depended on the curing condition.