Influence of the composition and shades of ceramics on light transmission and degree of conversion of dual-cured resin cements

• Published in: Journal of applied oral science 2019-01, Vol.27, p.e20180351-e20180351
• Main Authors: Mendonça, Luana Menezes de, Ramalho, Ilana Santos, Lima, Livia Aguiar Santos Nogueira, Pires, Laís Alcântara, Pegoraro, Thiago Amadei, Pegoraro, Luiz Fernando
• Format: Article
• Language: English
• Subjects: Ceramics; Dental materials; Dentistry; DENTISTRY, ORAL SURGERY & MEDICINE; Fourier Transform Infrared; Original; Polymerization; Resin cements
• ISSN: 1678-7757; 1678-7765; 1678-7765
• DOI: 10.1590/1678-7757-2018-0351

Since the transmittance of ceramics can influence the degree of conversion (DC) of resin cements, ceramics composition and shade should be considered in the selection of resin cement. This in vitro study aimed to evaluate the effect of the transmittance of different composition, opacities and shades of ceramics on the degree of conversion of two dual-cured resin cements. Sixty discs were prepared from low translucency (LT) and medium opacity (MO) lithium disilicate ceramic, and zirconia ceramic (Z). Each group was subdivided into 5 subgroups (n=4) in shades A2, A3.5, B2, C2 and D3. The transmittance measurement was performed in a spectrophotometer. The Variolink II and Rely X U200 resin cements were photoactivated by LED (1400 mW/cm2) for 40 s through the ceramic discs and without the discs (control group). The DC was measured with infrared FTIR spectroscopy, immediately after light activation. Data were analyzed with Kruskall-Wallis and one-way ANOVA, following post-hoc comparisons by Tukey test and Pearson's correlation test (P