An outstanding treatment challenge related to aesthetic monolithic materials is to mask discolored substrates in aesthetic areas. The purpose of the study is to evaluate the substrate masking ability of different resin composite materials and the influence of their association with luting agents and substrates. Five types of 2M2 HT (high translucency) resin composite materials were selected: Vita Enamic [E] and four types of nanoparticle-filled composites Lava Ultimate [L], Cerasmart [C], Shofu HC [S], and Hyramic [H]. Resin composite Vita VM LC with different shades was used for the substrates: 2M2, 3M2, and CP2. Variolink Esthetic Try-inpastes neutral, light+, and warm+ colors were chosen to simulate the luting agent color. Optical parameters (TP (translucency), CR (contrast ratio), and OP (opalesce)) and color differences ΔE (chromatic difference) were calculated. Statistical analyses were performed to evaluate the comparisons between the groups and establish correlations. TP average values for all materials were in the range of 21.49-24.53. OP average values were in the rage of 6.31-7.85. OP is moderate positive correlated to TP and CR is negative and strong correlated to TP. Related to materials, average color changes decrease as following: E > H > C > L > S. Referring to the tryin material, warm colors induce marked color changes of the restoration. The differences of the color changes determined by all studied substrates are significant. For the final aesthetic aspect of the restoration, it is essential to consider the underlying dental structure, luting agent, and restoration material as a whole unit. The masking ability of the investigated resin matrix ceramic materials materials shows differences, the best behavior demonstrated Shofu HC and Lava Ultimate. Marked color changes are related to high chroma substrates. For substrates with a darker color, the association with warm try-in pastes lead to marked color changes, but with neutral and light try-in pastes at most perceivable.
Keywords: luting material; masking ability; resin-composite; substrate.