Influence of the resin cement color on the shade of porcelain veneers after accelerated artificial aging

Resumo

Objectives: The aim of this study was to evaluate the influence of the color of the resin luting cement in the final shade of minimally invasive porcelain veneers after accelerated artificial aging (AAA). Material and methods: 20 bovine teeth were collected, prepared and divided into two groups. The roots were removed and the buccal surfaces were polished to obtain a flat surface. Porcelain discs (IPS Empress Esthetic) were produced to a standardized shade (ET1) and thickness (0.6mm). The teeth and the veneers surfaces were prepared according to manufacturer recommendations. For group I (n=10), the White-Opaque (WO) base-paste was used and for group II (n=10) the Yellow (Y) base-paste. Each specimen was photocured for 60 s. The specimens were next subjected to AAA. They were submitted to color readings with a spectrophotometer in three moments: after the preparation (only the substrate), after the cementation and polymerization of the veneers and after the AAA. Were obtained values of L*, a* and b* and the total color change was calculated (∆E*). Values obtained were subjected to statistical analysis in SPSS 17.0 for Windows with a significance of 0.05. Results: When comparing the cements, the Y cement showed higher ∆E*, lower L* and higher b* after AAA than the WO. Conclusion: Both cements could mask the substrate color. With AAA, only the Y shade showed a ∆E* clinically unacceptable, becoming more yellow (higher b*) and losing lightness (lower L*).