Method:
Ultradent Opalescence PF Home and Ultradent Opalescence Boost Office were used as home and office bleaching agents. As for the restorative materials, nanofilled composite Filtex Z350 XT, the sub-micron composite Estelite Sigma Quick, and nanofilled glass ionomer Ketac N100 nano ionomer were used
Samples were fabricated using plexiglass discs of 6 mm diameter and 2 mm height in three groups: I (Filtex Z350 XT), II (Estelite Σ), and III (Ketac Nano) where n=90. Each group was further divided into three subgroups (n=10): A (home bleaching), B (office bleaching), and C (Distilled water) as control. Samples were bleached and rinsed following the manufacturer’s instructions for a two week period. Discoloration can be evaluated with different instruments and techniques. The Commission Internationale de I’Eclairage (CIE L*,a*,b*) system was chosen for image processing. Photos of samples were taken with a Nikon D200 digital camera and CIELAB color values were analyzed from digital raw images taken from the samples using software Photoshop CS3 Ver 10.0.
Result:
All dental restorative materials showed significant color changes (ΔE). Statistical significance was declared if the P value was ≤ 0.05. The mean color change of Estelite Σ (3.82±1.6) was the highest, followed by Ketac Nano (2.97±1.2). Filtex Z350 XT showed the least color change (2.25±1.0) with all bleaching agents.
Conclusion:
Sub-micron resin composite showed the highest color changes followed by Ketac nano-ionomer. The Nano filled composite was found to be highly stable in terms of color. Nano filled composite and glass ionomer showed better color stability compared to microfilled tooth color materials.