Influence of Activation Mode of Resin Cement on the Shade of Porcelain Veneers

Publicado em 20-05-2013

Ana Paula Rodrigues Magalhães, Paula de Carvalho Cardoso, João Batista de Souza; Rodrigo Borges Fonseca, Fernanda de Carvalho Panzeri Pires-de-Souza, & Lawrence Gonzaga Lopez,
Dental veneers; resin cements; color perception tests; polymerization; aging.


Purpose: The aim of this study was to evaluate the influence of resin luting cement’s activationmode in the final shade of porcelain veneers after accelerated artificial aging (AAA).
Materials and Methods: Porcelain veneers (IPS Empress Esthetic) were produced using a standardized shade (ET1) and thickness (0.6 mm). Twenty bovine teeth were collected, prepared, and divided into two groups: group I (n = 10)—light-cured group, only base paste was applied to the veneers; group II (n = 10)—dual-cured group, in which the same base paste used in group I and a transparent catalyst were proportionally mixed for 20 seconds and then applied to the veneers. The specimens were light-cured for 60 seconds each and were next subjected to AAA. They were submitted to color readings with a spectrophotometer in three instances: in the tooth surface (only the substrate), after the cementation and polymerization of the veneers, and after the AAA. The values of L*, a*, and b* were obtained and the total color change was calculated (E*). Values obtained were subjected to statistical analysis,
with a significance of 0.05.
Results: There were no significant differences between dual- and light-cured modes considering E*, L*, a*, and b* values obtained after aging (p > 0.05). Within the dual-cured mode there were no significant differences in E*, L*, a*, and b* values (p > 0.05).
Conclusion: No relevant differences were found between the two activation modes in color change. When submitted to aging, dual- and light-cured modes of the resin cement showed visually perceptible (E* > 1.0) color changes; however, within the threshold of clinical acceptance (E* > 3.3).