Staining Susceptibility of Microhybrid and Nanohybrid Composites on Exposure to Different Color Solutions

Abstract

Composite discoloration is considered one of the most significant disadvantages of dental restorations. The purpose of our study was to assess the color susceptibility of two esthetic composite filling materials, microhybrid composite (ValuxTM Plus) and nanohybrid composite (FiltekTM Z250 XT), to different solutions and compare the results among different measuring methods (Intraoral scanner, Easyshade spectrophotometer, and Vita classical shade guide). A total of 100 specimens were fabricated in this experimental study. Each sample was soaked in either Coca-Cola, orange juice, tea, coffee, or distilled water for 30 days. Color measurement was performed using the spectrophotometer, IOS 3Shape Trios, and Vita classical shade guide. L*a*b* values were recorded to determine the color changing (ΔE00). The significance level was p < 0.05. All samples showed clinically visible color changes after immersion in coffee, tea, orange juice, and Coca-Cola. The nanohybrid composite showed high color change when placed in tea (ΔE00 = 12.5) measured by the Intraoral scanner, spectrophotometer (ΔE00 = 23.21), and by Vita classical shade guide (ΔE00 = 25). Less color discoloration was perceptible in the microhybrid composite when immersed in Coca-Cola (ΔE00 = 1.78) measured by spectrophotometer, intraoral scanner (ΔE00 = 2.85), and measured by Vita classical shade (ΔE00 = 3.2). The results showed that measurements with the spectrophotometer and Vita classical shade guide were correlated. The results were analyzed using the chi-square and Wilcoxon signed-rank tests, and there was a significant difference (p < 0.001) in both composite resins for all the solutions, with microhybrid being more color stable. Microhybrid composite had more color stability than nanohybrid composite, especially when immersed in tea and coffee. The spectrophotometer with Vita classical shade guide showed better interrater agreement than with the intraoral scanner.

Properties of Nanohybrid Dental Composites—A Comparative In Vitro Study

“…The nanohybrid composites are designed for a complex dissipation of the mechanical solicitation within the microstructure to prevent particles delaminating and cracks propagating. This characteristic is sustained by the increased values of the compression and flexural strength of the nanohybrid structures [19,20]. Thus, a uniform filler distribution within the resin base is very important for a homogeneous material with constant mechanical properties.…”