Evaluation of color stability and surface roughness of smart monochromatic resin composite in comparison to universal resin composites after immersion in staining solutions.

Abstract

Background: The color stability and surface roughness of resin composites are the primary factors influencing the qualities of restorative materials. This study aimed to assess the color stability and surface roughness of a smart monochromatic resin composite submerged in various staining solutions.

Materials and methods: Ninety-nine disc samples of composite resins (8 mm in diameter and 2 mm in thickness) were prepared and divided into three groups (n = 33): Group A, Omnichroma (Tokuyama Dental, Tokyo, Japan); Group B, Neo Spectra ST HV (Dentsply, Konstanz, Germany); and Group C, Filtek Z350XT (3MESPE) composite resins. The samples were assessed for color stability (M) via a Vita Easyshade spectrophotometer and surface roughness (Ra) with a profilometer before and after thermocycling for a total of 1000 cycles at 5°/55°C with a 15-second dwell time. Each group was subdivided into three subgroups according to immersion solution (n = 11): Subgroup I was submerged in distilled water as a control, Subgroup II was submerged in tea, and Subgroup III was submerged in coffee. Color assessment was performed after immersion periods of T1: 7 days, T2: 15 days, and T3: 30 days with a Vita Easyshade spectrophotometer. A color change (∆E00) was obtained via the CIEDE2000 color difference formula. Surface roughness was assessed with a profilometer after 30 days of submersion in the staining solutions.

Results: Among all the samples in the study groups, Omnichroma had the lowest color change value for all the immersion solutions at different time intervals (p < 0.001). The surface roughness of Omnichroma significantly differed after thermocycling (P = 0.075). However, Omnichroma had the least surface roughness compared with Neo Spectra ST HV (P = 0.026) and Filtek Z350XT (P = 0.024).

Conclusion: The color change and surface roughness of the supra-nanofilled (Omnichroma) resin-based composite were inferior to those of the nanohybrid (Neo Spectra) and nanofilled (Filtek Z350XT) composites.