Surface Texture and Optical Properties of Self-Adhering Composite Materials after Toothbrush Abrasion

This study evaluated the surface texture and optical properties of two self-adhering composites and a nanofilled composite before and after toothbrush abrasion. Vertise Flow (Kerr), Fusio Liquid (Pentron Clinical) and Filtek Z350 XT (3M ESPE) composites were divided into 3 groups (n = 6). Disks of 12 mm diameter and 2 mm thick were made. All materials were light-cured with a LED light source for 40 seconds. Analyses of surface roughness, gloss retention and color stability were performed 24 hours after light curing and after 20,000 brushing cycles. Data were analyzed with analysis of variance (ANOVA) and Tukey's test (α = 5%).

Tukey's test ascertained that toothbrush abrasion resulted in rougher and matte surfaces for all composites tested. Filtek Z350 presented better gloss retention after abrasion. On surface roughness evaluation, there was no statistical difference between Fusio Liquid Dentin and Filtek Z350 resins (p > 0.05). Vertise Flow resin showed better color stability (ΔE), than the other two materials.

Nanofilled material presented better gloss retention but it did not produce the best results in aspects related to surface roughness and color stability compared to self-adhering composites.

A simulation of degradation process by using toothbrush abrasion produced a rougher and matte surface in all composites tested. The surface texture was not only related to filler's amount present in materials, but also with the organic matrix composition of them. The results suggested that the constant development of new materials, seeking for a technical simplification, seems an innovative attraction for dentist's clinical routine, even though larger studies are necessary to promote to everyone a better understanding and improvement of action and effectiveness of this new class of materials.