Autores: Jaime Portugal, Luis Pires Lopes, Miguel Fonseca
Instituição: Faculdade de Medicina Dentária de Lisboa, Centro de Matemática da Universidade Nova de Lisboa
Valor da bolsa: 300.00€
Apresentação durante o evento IADR em Dubrovnik, Croácia | 2014-09-10
Resumo:
Objectives: To evaluate the effect of zirconia pigmentation and exposure time on the ability to light cure resin cement through three zirconia ceramic systems.
Methods: Five ceramic blades, 0.6 mm thickness, were made for each zirconia system in study. Resin cement (Variolink II Base) disc shaped specimens (5mm x 0.5mm) were prepared. The resin was light cured (1420 mW/cm2 - Bluephase 20i) through ceramic blades. Forty-five experimental groups were set according to the several possible combinations between three ceramic system (LAVA, ICE Zirkon Translucent and Prettau Zirkon), three ceramic pigmentation (no pigmentation, A1, A4), and five exposure time (10, 20, 30, 40 and 50 seconds) (n=5). The ability to light cure was determine by Knoop microhardness evaluation. Data were statistically analyzed with 3-way ANOVA followed by Tukey post hoc tests (Alfa=0.05).
Results: Zirconia systems (p<0.05), zirconia pigmentation (p<0.05) and exposure time (p<0.05) had a significantly effect on microhardness. We also observed a statistically significant interaction between exposure time/pigmentation (p<0.05), zirconia system/pigmentation (p<0.05) and exposure time/zirconia system/pigmentation (p<0.05). Photopolymerization for 50 seconds had the higher microhardness but not statistic significantly different for 30 and 40 seconds. Between the different zirconia the ICE Zirkon Translucent has the higher microhardness. The results obtained with the three pigmentations were all different and A4 was significantly higher. No pigmentation decreased mean microhardness.
Conclusions: The ability to light cure resin cement through zirconia framework is influenced by zirconia system, zirconia pigmentation and exposure time.
Keywords: zirconia, pigmentation, resin cement, microhardness, Light curing.
