In vitro evaluation of discoloration and surface alteration in self-adhesive resin cements using CIELAB and 3D profilometry.

BACKGROUND

Self-adhesive resin cements (SARCs) are widely used in the field of restorative dentistry due to their simplified application and adequate bonding properties. However, their long-term color and surface stability, particularly under the influence of pigment-rich dietary substances, remain a critical concern in aesthetic restorations.

OBJECTIVES

The aim of the study was to evaluate the color stability and surface roughness of 4 contemporary SARCs after immersion in various staining media using digital photography.

MATERIAL AND

METHODS

A total of 160 disc-shaped specimens (n = 40 per group) were fabricated from 4 SARCs: Maxcem Elite™ (MXC); G-CEM ONE™ (GCO); SpeedCEM® Plus (SPC); and RelyX™ Universal (RLX). The specimens were immersed in artificial saliva, coffee, red wine, or matcha tea at 37°C for 0 (T0), 7 (T1), 14 (T2), 21 (T3), and 28 (T4) days. Color changes (ΔE₀₀) were measured, and surface roughness parameters were evaluated using 3D laser scanning microscopy. The statistical analysis was performed using linear mixed models (LMMs) and Tukey's honestly significant difference (HSD) post hoc test (α = 0.05).

RESULTS

All materials showed visually perceptible color changes (ΔE₀₀ > 1.1). The highest discoloration and roughness values were observed in MXC, especially after exposure to red wine. RelyX™ Universal exhibited the greatest resistance to staining and surface degradation. 2-Hydroxyethyl methacrylate (HEMA)-based SARCs (MXC, GCO) were more susceptible to pigment infiltration and roughness increase than urethane dimethacrylate (UDMA)-based cements (RLX, SPC).

CONCLUSIONS

The aesthetic stability of SARCs is influenced by both material composition and exposure to staining agents. Red wine caused the most severe discoloration and surface changes, followed by coffee, matcha tea and artificial saliva. Higher water sorption and surface roughness were associated with increased staining. Preserving surface integrity is essential for maintaining the long-term aesthetic performance of SARCs.